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LIST OF TECO COMMANDS, TECO VERSION 1132
Last updated 9 March 1985. Z=232280
(Note that a caret followed immediately by another character signifies a
control character, except inside FS flag names, where that is not necessary
because control characters are not allowed.)
^@:
<n>^@ for nonnegative <n>, is the same as ".,.+<n>". For negative <n>, is
the same as ".+<n>,.". "10^@XA" puts the 10 characters after the
pointer in a string in qreg A.
<n>,0^@ returns -<n>; this is often useful. <m>,<n>*0^@ returns -<m>;
it undoes the ",<n>". In other words, it extracts the first of two
args. If you want <m> instead of -<m>, use another ,0^@.
<m>,<n>^@
returns the value <n>-<m>.
<m>,<n>:^@
returns <n>,<m>.
^A Inclusive-or (an arithmetic operator).
Used in a file specification as the first or the second filename to
stand for the default first name.
^B A command for cleaning up after failing searches. If the last search
was successful, ^B does nothing. If the last search failed, ^B moves
to the end of the range searched if it was a forward search; to the
beginning, if it was a backward search. :^B does the same thing for
failing searches but does FKC after successful ones.
Inside search string is a special char which is matched by any
delimiter character. The set of delimiter chars is specified by the
contents of q-reg ..D; initially, the delimiter characters are
precisely the non-squoze characters (that is, all except letters,
digits, ".", "%" and "$").
May be used in a file specification as the first or second file name to
stand for the default second name.
^C when typed in from console, terminates the command string, and starts
execution. If the command executes without error, TECO returns to its
superior without flushing the type-in buffer. When proceded, it will
automatically redisplay the buffer on display consoles. When TECO
returns, AC 2 will contain the address of the 7-word "buffer block"
describing the current buffer--see the section "buffer block" at the
end. To type in a ^C in a TECO command string, use ^]^Q^C, which is
specially arranged to inhibit the normal action of ^C at command string
read-in time. A ^C encountered as a command is an error.
^F inserts its string argument, after deleting the last thing found with
an S search or inserted with I or \ (won't work if pointer has moved
since the S, I or \ was done). Precisely, ^F is the same as FKDI.
^G causes a "quit" by setting FS QUIT to nonzero. The consequences of
that depend on the value FS NOQUIT. Normally, FS NOQUIT is 0; ^G
will then stop whatever TECO is doing and return to its top-level loop,
or to the innermost ^R invocation if any, to read more commands (but
first TECO will redisplay the buffer). In particular, it will cancel a
partially typed-in command string. All unread input except the ^G
itself is flushed. On printing terminals, output is also discarded.
(If FS NOQUIT is -2 or less, this is inhibited). If FS NOQUIT is
positive, ^G still sets FS QUIT but that has no effect. Thus, a
program can inhibit quitting temporarily, or quit in its own manner by
testing FS QUIT itself. If FS NOQUIT is negative, setting FS QUIT
nonzero causes an ordinary error (whose error code is "QIT"), which may
be caught by an errset (:< - >). If FS NOQUIT is less than -1, then
in addition the input and output on the terminal are not discarded.
^H backspace; it is illegal as a command.
^I tab; in bare TECO, it is a self-inserting character. In EMACS, or
whenever FS ^I DISABLE is appropriately set, it is equivalent to a
space. In bare TECO, it inserts itself as well as the following string
argument, so that Tab is equivalent to I Tab. This was intended to be
typed by the user himself; using it in a macro is foolish.
Tab characters in the buffer or in typeout are displayed using tab
stops at a spacing controlled by FS Tab Width.
^J line feed; flushes current value.
^K<string>
valrets a string argument to DDT with dollar signs replaced by
altmodes. (To cause a dollar sign to be valretted, use "^]^Q$"
(ctl-close ctl-Q dollar)). If the command string contains an P
command, TECO command execution will continue with the character after
the altmode ending the text string of the ^K. ^K causes TECO to
believe that the screen has been clobbered, so it will automatically
clear the screen and redisplay everything at the next opportunity. To
avoid this, use "@^K" (if for example you know DDT will not type
anything out, and will P the TECO).
When TECO executes the .VALUE, AC 2 will contain the address of the
7-word "buffer block" describing the current buffer--see the section
"buffer block" at the end.
^L form feed; clears screen on displays (when executed, not when typed).
See F+ for more details.
^M carriage return; flushes current value. If FS STEP MACRO is a string,
it is executed. (If there is a ^J after the ^M, it is skipped over
first.) If FS STEP MACRO is a nonzero number, ^M does these things
designed to step through the program a line at a time: it displays the
buffer unless there was typeout recently, then reads in a character and
acts according to it. Most characters simply tell ^M to return so that
more commands will be executed. However, there are the following
special characters:
^F quit. Like ^G, but ignores the setting of FS NOQUIT and does
a real quit.
^P end stepping. Zeroes FS STEP MACRO and then proceeds without
stepping.
^R enter ^R mode. On return from ^R, another character will be
read and decoded.
^N:
<n>^N sets the FS LINES flag to <n>. Like "<n>FS LINES". FS LINES
controls the number of lines used for buffer display and, on display
terminals, for all other output.
:^N complements the FS TTMODE flag (initially 0). TECO normally displays
the buffer on printing terminals only if this flag is set. User buffer
display macros should exhibit similar behavior.
:<n>^N like "<n>^N :^N"
Note: ^N in a search string is a special char which is matched by any
char other than the char after the ^N in the search string.
^O<filename>
bigprints <filename> on the device open for output.
In a search string ^O is a special character signifying "OR" i.e., it
divides the search string into two strings either of which will satisfy
the search. Thus, SFOO^OBAR will find either FOO or BAR, whichever is
encountered first.
^P alphabetic (ASCII) or numeric sort command. The entire buffer, or the
part within the virtual boundaries, is sorted, after being divided into
sort records (i.e., things to be sorted) on the basis of the arguments
given to the command in the form of three TECO command strings
following the ^P, separated by altmodes.
(Notes: (1) two successive null args will result in a premature end of
command input, so use spaces where needed; (2) a dollar sign in any arg
will be replaced by an altmode; (3) the three args will be left in
q-regs ..0, ..1, ..2).
The three expressions are used to divide the buffer into sort records,
each of which has a sort key. A sort key may be any substring of the
record, or it may be a number. The records and keys are found as
follows:
1. The pointer is moved to the beginning of the buffer, which is the
beginning of the first sort record.
2. The first command string is executed. If the key is to be a
substring of the record, this command string should leave point at the
beginning of the key. If the key is to be a number, it does not matter
what this command string does.
3. The second command string is executed. If this command string
returns a value, that value is the key. Otherwise, this command string
should leave point at the end of the key.
4. The last command string is executed. This should move the pointer
to the end of the sort record, which is also the beginning of the next
record.
5. If step 3 or 4 leaves the pointer at the end of the buffer, the
creation of sort records is complete, and the sort takes place.
Otherwise, go back to step 2.
Sort records and keys may be variable length. No character (i.e., a
shorter key) sorts before ^@, and keys are considered left-justified
for the comparison. Numeric keys are always "less" than any string
keys. Failing search commands are not errors while scanning for sort
records, unless the FS S ERROR flag is nonzero. It is recommended
that this flag be set, since code is easier to debug if all searches
which are supposed to be allowed to fail have an explicit colon.
There is nothing to prevent overlapping records from being specified;
the sort will copy each record so the overlap region will be
duplicated. Insertion and deletion are allowed but know that TECO
remembers the boundaries of records and keys as character numbers, so
deleting chars from a record already delimited will shift chars from
the next record into it, etc. The sort is stable. :^P sorts in
reverse order. If FS ^P CASE is nonzero, ^P ignores case; that is, it
sorts lowercase letters as if they were the corresponding uppercase
letters.
^Q ^Q in a search string causes the next char to be quoted, i.e., it is
treated as an ordinary char even if it normally has a special meaning
("^Q^Q" is a normal ^Q; ^Q works only at execution time, not at command
string read-in time, so rubout cannot be ^Q'd). This also works inside
file name specifications.
^R MODE
^R real time edit feature, intended mainly for display terminals. The
position of the pointer is represented by the terminal's hardware
cursor, rather than by any printed characters (^R ignores the contents
of ..A, except on printing terminals).
All non-control-non-rubout characters are normally self inserting; the
others are normally editing commands. The user may redefine any char-
acter by means of the FS ^RCMAC flag. In ^R mode echoing is turned
off, so typed-in characters manifest themselves only by their effect on
the displayed buffer contents (but see FS ^R ECHO).
Any command may be given a numeric argument, which most commands
(including all characters that insert themselves) treat as a repetition
count. If no argument is specified, 1 is the default, but commands can
distinguish between an explicit 1 and a defaulted 1. The argument is
computed as follows:
<arg> = <basic arg> * (4 ** <exponent-of-4>)
where <basic arg> is the explicit argument, if any, or 1 otherwise. An
explicit argument is given with ^V or by control-digits. <expt-of-4>
is initially 0 and incremented by ^U. All commands except argument-
setting commands discard their arguments even if they don't use the
arguments. Three flags contain the argument data: FS ^R ARG contains
the explicit argument, if any, else 0; FS ^R EXPT contains the
exponent of 4; FS ^R ARGP, if zero, indicates that no arg has been
specified (neither the explicit arg nor the exponent of 4); if 1,
indicates that only an exponent of 4 has been specified, and the basic
arg is still 1; if 3, indicates that an explicit arg has been speci-
fied. The 4 bit, if set, indicates that the argument should be
negated. (Control-Minus sets this bit.) All three are zeroed after
any command that doesn't identify itself as an argument setting command
by clearing FS ^R LAST.
Any character may have a program associated with it, using the FS
^RCMACRO command. If that is done, when that character is typed, TECO
will execute the program instead of inserting the char or using it as a
built-in command. The definition of a character may also be treated as
a q-register in the "Q", "U", "X", "G", "[", "]", "M" and "FQ"
commands; see "Q" for directions. When the program is executed, q-reg
..0 will contain the character being handled.
When errors take place inside ^R, or in macros called from ^R, after
printing the error message TECO returns control to the innermost
invocation of ^R (unless FS *RSET or ..P is nonzero). The same thing
happens for quits. See ..P.
One may wish to have a mode in which most editing commands are
disabled, and most characters that are normally editing commands are
self-inserting instead. The FS ^RSUPPRESS flag, when nonzero,
suppresses all built-in commands except rubout and all user defined
commands whose definitions do not begin with "W". (Since "W" at the
beginning of a macro is a no-op, the only reason to have one there is
to prevent suppression.) When a character is suppressed as a command,
it becomes self-inserting. An additional feature is the FS CTL MTA
flag; when it is negative, all control-meta-letters (and ctl-meta-[, ],
\, ^ and _) have their definitions suppressed; this mode is useful when
editing TECO commands.
In "replace mode", printing characters overlay a character instead of
making the line longer. Replace mode is controlled by FS ^R REPLACE,
which see for more details. A more general facility for changing what
ALL printing characters do is FS ^R NORMAL. If this is nonzero, it
counts as the definition of all "normal" characters. That is, the
definition which all printing characters initially have says to do
whatever FS ^R NORMAL directs, and otherwise (if it is 0) insert or
replace.
You can redefine all "normal" characters whose Lisp syntax in ..D is
")" by putting a function in FS ^R PAREN. This function will be
executed IN ADDITION to the actions for handling all "normal" charac-
ters. This is good for something to point out the location of the
matching open-parenthesis.
Normal characters which you don't redefine in one of those ways will
sometimes be subject to system echoing, when that is implemented. This
improves efficiency so it is done whenever it is safe. Characters
which have been redefined and thus made not normal cannot be echoed by
the system. If you redefine what "normal" means by making FS ^R
NORMAL nonzero, system echoing will be turned off entirely. Sometimes
Space is redefined with a definition which never does anything but
insert a space unless the horizontal position is beyond a certain point
(at which point it will typically break the line). Then it is desir-
able to enable spaces to be echoed when the cursor has not reached that
column. This can be done by means of the FS ^R EC SD flag. Set it to
the definition which Space has in that case, and set FS ADLINE to the
column up to which it is safe to echo Space. Then, when Space actually
has that definition, the system will be told to echo spaces but only up
to that column.
By setting FS ^R INHIBIT nonzero, you inhibit display updating. But
^R still remembers what is necessary, and as soon as FS ^R INHIBIT is
zero again the updating will be done.
Conversely, you may wish to inhibit the feature which causes redisplay
to be suspended when input is available. Setting FS D FORCE nonzero
does this.
The ^R-mode input dispatch table is actually indexed by 9-bit TV
character code. Each 9-bit code can be redefined. The list of ^R-mode
initial definitions that follows refers to the characters obtainable on
non-TV's--in other words, the 9-bit characters which are the results of
reading in the 14-bit codes 0000 through 0177, which are precisely the
9-bit characters which are equivalent to some 7-bit ASCII character. A
subsystem which is not TV oriented need not worry about the 9-bit
character set; by using FI, and FS ^RCMACRO always without the atsign
modifier, it can handle ASCII characters throughout. TECO will
automatically do the conversion to and from 9-bit characters on TV's.
For those who wish to handle the 9-bit character set, the definitions
of all 9-bit characters are listed in the section "TECO's character
sets," along with the appropriate conversions between character sets.
One may wish to have some operation (such as filing the buffer away)
performed every so often while in ^R mode. See "..F" for how to do
this using the "secretary macro" feature. FS ^R DISPLAY can be set to
a macro which will be run every time ^R is about to do nontrivial
redisplay.
Although ^R mode is intended for display terminals, the creation of
large macro-systems intended for use with ^R mode has made it necessary
for ^R to work at least marginally on printing terminals. Since the
physical cursor is not suitable, the ordinary TECO cursor is used
(whatever is in ..A). The buffer is displayed only when the screen is
"cleared", such as by giving the built-in ^L command. Also, unless FS
^RECHO > 0, characters actually read by the ^R-mode command loop are
typed out, although echoing is still turned off. This echoing can be
made to happen even on displays by making FS ^RECHO negative (this is
unwise to do if there is no echo area).
Setting FS ^R SCAN to nonzero causes ^R commands to try to imitate
printing terminal line editors by echoing the characters that they
insert/delete/move over. In this case, FS ^R ECHO should be set to 1.
FS ^R MAX is the maximum size deletion or insertion which ^R will try
to print in the fancy way. If you define FS ^R TTM1, it gets to try
to handle any redisplay ^R does not have a way of handling. See its
definition. Note that ^R recognizes insertion, deletion, and cursor
motion from the values returned by the user's command definitions--see
the following paragraph.
Macros and ^R - reducing redisplay:
Whenever control passes from normal TECO to ^R (that is, when a ^R is
executed, when a @V is executed within a ^R-mode macro, or when a
^R-mode macro returns), ^R must be able to update the screen according
to the changes that have been made in the buffer since the last time ^R
mode lost control. ^R can do that in a way that makes no assumptions,
but that way is slow. If information is still available on what areas
of the buffer were changed, that info can be passed to ^R in the form
of numeric args, and ^R will save time by assuming the info to be
correct. If the info is not correct, the screen will not be properly
updated. The options are: no args--the usual case--means assume
nothing. One arg means that the buffer has not changed, although the
pointer may have moved. The actual value of the arg does not matter in
this case. Two args should specify a range of the buffer outside of
which nothing was changed. ^R will limit redisplay to that range if
possible. ^R also knows what to do about macros that type text out; if
Q..H is nonzero when ^R is entered or returned to, ^R will not do any
displaying until it has read one character (and executed it, unless it
is a space). If the selected buffer when you return to ^R is not the
same one that was selected when ^R was previously in control, then it
doesn't matter what args you give.
If you like ^R mode, try:
:I..G EL 90^S ^R :I..B Q..H"N 90^S ' ^R
The commands are:
Control-Minus
negates the argument of the next command.
Control-digits
accumulate a numeric argument for the next command. Thus,
control-5 ^N will move down five lines.
^A go to beginning of current line (0L). With argument, <arg>-1L.
^B go back over previous character (R)
^C complements the state of the comment mode switch. Types "C"
for comment or "T" for text at the bottom of the screen, to say
what mode you're in. When in comment mode, the ^N and ^P
commands begin by going to the end of the line and if the last
character is a semicolon, deleting it and any preceding tabs.
Then, after moving to the next or previous line, if the line
has a semicolon in it the pointer will be left after the
semicolon; otherwise the pointer will move to the end of line,
and enough tabs will be inserted to move the pointer at least
to the specified comment column, followed by a semicolon.
Numeric argument is ignored.
^D deletes the next character after . (D) If FS RUBCRLF is
nonzero, ^D before CRLF deletes both the CR and the LF.
^E moves to end of line (:L). With argument, <arg>:L.
^F goes forward over the next character (C)
^G flushes any numeric argument or case-shift, unsets the mark if
it had been set, and resets the case-lock. When ^R is actually
in control (as opposed to a macro running inside ^R), ^G's
quitting action is suppressed, and ^G acts as a command
instead. Thus, it does not flush any type-in.
^H (backspace) inserts itself.
^J (linefeed) inserts itself.
^K kills to eol (K). With arg, <arg>K. The text deleted is put
in q-reg ..K.
^L redisplays the screen (used to recover from datapoint lossage).
Chooses a new window. A numeric argument specifies the number
of lines of buffer to display--useful on printing terminals.
On displays, if only a part of the screen is being used at the
moment, only that part is cleared.
^M inserts a carrage return-line feed.
^N goes to next line (L). With argument, <arg>L.
^O inserts a CRLF, then backs over it. "^Ofoo" is equivalent to
"foo^M" but often requires less redisplay. With argument,
inserts <arg> CRLFs and backs over the last. If you want to
insert several lines in the middle of a page, try doing ^U^U^O
before and ^U^U^K afterward.
^P goes to previous line (-L). More generally, -<arg>L.
^Q inserts the following character directly, regardless of its
meaning as a command. If the char isn't already in the input
buffer, ^Q will prompt with a "Q" at the bottom of the screen.
An argument to ^Q causes it to insert the same character <arg>
times. ^Q is not affected by replace mode; the quoted
character is always inserted.
^R causes the column the pointer is at to become the comment
column. Argument is ignored.
^S reads a character and searches for it. "^SA" in ^R mode is
like "SA" in TECO.
^T sets the ^R-mode mark at the current pointer position. The
mark is really the value of FS ^RMARK and is used by the ^X
and ^W commands in ^R mode. If FS ^R MARK holds -1 there is
no mark; that is the case initially and after any insertion,
deletion or quit in ^R mode. Attempting to use the mark when
there is none rings the bell.
^U increments the exponent-of-4 for the next command. This
usually is the same as repeating it 4 times. Does not use any
previous argument, but leaves it around for the next command.
^V sets the basic arg for the next command. The argument is
composed of digits optionally preceded by a minus sign, echoed
at the bottom of the screen and turned into a number in the
current radix (FS IBASE). The first non-digit terminates the
arg and is treated as a command. ^G will flush the argument.
^W kills everything between the current pointer position and the
mark, putting the deleted text in q-reg ..K. If there is no
mark, nothing is deleted and the bell is rung.
^X sets the mark at the current pointer position, and moves the
pointer to where the mark had been; in other words, exchanges
the mark and the pointer. Does nothing if there is no mark.
Do this several times to see both ends of the range that a ^W
command would delete.
^[ (altmode) terminates edit
^] reads a q-reg name and executes that q-reg as a macro. The
q-reg should contain ordinary TECO commands, not ^R mode
commands. The numeric arg to the ^] will be given to the macro
which will see it as the value of ^Y (If no argument is
specified, ^Y will be 1, but F^X will indicate that the macro
had no argument). The macro may return values to ^R telling it
which areas of the buffer may need redisplay (see below). If
the macro is to return values, it should end with a space--
otherwise, the values might get lost within TECO. Example:
".,( G..K .) "
gets q-reg ..K and returns 2 values limiting the range of the
buffer in which changes took place.
^? (rubout) deletes bacwards (-D). If FS RUBCRLF is nonzero,
rubout when the pointer is after a CRLF deletes the whole CRLF.
ctl-rubout
deletes backwards like rubout, except that tabs are converted
to spaces and the spaces are deleted one at a time.
^S:
^S in a search string is a special character which should be followed by a
Lisp-syntax value and matches any character whose Lisp syntax in Q..D
matches the specifed syntax value. For example, ^S( matches any
character whose Lisp syntax is "(".
<n>^S if <n> is positive, sleep for <n> 30ths of a second. If <n> is
negative, sleep until system run time (what FS UPTIME gets) = -<n>.
<n>:^S sleep for at most <n> 30ths of a second, returning immediately if there
is any input available. Returns the value of FS LISTEN (nonzero if
input is available).
^U display in the user-specified manner the directory of the current
default device. That is, invoke the user's buffer display macro if
any; otherwise on display consoles display in the standard manner, but
do nothing on printing terminals. These are the same actions TECO
always takes at the end of any command string whose last command was an
E-command.
Note: if ^U is typed as the first character of a command string, it is
executed immediately when read.
^V pops the "ring buffer of the pointer". ^V when the first character of
a command string acts immediately, resetting the pointer to the value
it had before the last time it was moved. Successive ^V's will undo
earlier changes of the pointer. Up to 8 changes are remembered to be
undone. Motion caused by the use of ^V in this manner does not get
saved to be undone. ^V not the first character typed is slightly
different. It pops the ring buffer into the pointer, and returns as
its value the number that then remains on the top. If that returned
value is put in Q..I (which is what gets pushed on the ring buffer at
the end of the command string) you can fool TECO's top level into
thinking that the pointer was not moved by the command string that just
finished, so nothing will get pushed back on the ring buffer (this is
exactly what ^V as the first character typed does). If TECO's top
level is not in use, the program that is running must be hacked up to
push explicitly on the ring buffer (using <n>^V) in order for anything
to appear on it. If ^V attempts to jump out of the buffer, the pointer
is not moved, but the ring buffer is popped. A "NIB" error happens.
:^V returns the value on the top of the ring buffer, without popping it or
changing the pointer.
<n>^V is equivalent to <n>FS PUSHPT. It pushes <n> onto the ring buffer
unless <n> equals whatever is at the top of the ring buffer.
<n>:^V pushes <n> onto the ring buffer unconditionally.
^W pops all the way to top level, exiting from any break-loops and not
running the user defined error handler in ..P.
^X Only defined inside macro. Its value is the first arg of the M command
which called the macro. See the F^X command for a more sophisticated
way for macros to examine their arguments. Note: ^X typed as the first
character of a command tells TECO to type out the whole error message
associated with the most recent error. If the flag FS VERBOSE is zero
(normally true on printing terminals) TECO normally types only the
3-letter code. Use ^X to see the whole message if you don't recognize
the code.
In search string is a special char which is matched by any character.
May be used in a file specification as the first or the second filename
to stand for the default first name.
^Y like ^X, only second or only arg of the M command. If ^Y is the first
char typed in in a command string, the most recently typed command
string longer than 7 characters (not counting the 2 altmodes) is
inserted in the buffer. This is a loss recovery procedure.
may be used in a file specification as the first or second file name to
stand for the default second name.
^Z normally causes an interrupt to DDT when typed. However, one can be
given to TECO by quoting it with ^_ , in which case it is a normal
command: with no arg, its value is a pseudo-random number.
<n>^Z inserts <n> random letters before the pointer.
Altmode terminates following text argument to certain commands; two successive
altmodes terminate a command string in the bare TECO command loop, and
begin execution of the commands in the command string. Execution of an
altmode as a command depends on the setting of FS NOOP ALTMODES. If
the flag is >0 (old-fashioned mode), altmode acts like the ^_ command.
If the flag is negative (default mode), altmode is a no-op. If the
flag is zero (losing mode), altmode is an error as a command.
^\ exits from the innermost macro invocation, unwinding the q-register pdl
to the level it had when the macro was entered, and popping all itera-
tions that started inside that macro. Note that if Q..N is popped this
way, its previous contents (before the pop) will be macroed (after the
pop is done). This enables macros to arrange arbitrary actions to be
performed whenever the macro is exited, no matter for what reason. See
also FS BACK RETURN.
:^\ exits from the innermost macro invocation, without unwinding the
q-register pdl. It does pop iterations.
^] string substitution
^] is not really a command. It is a special character that makes it
possible to substitute the contents of a q-reg into the TECO command
stream at any point (such as, inside an I or S command). ^] is pro-
cessed when TECO reads a character from the command buffer (i.e.,
before anything like insertion or execution is done to the character.).
It gobbles the next character and decodes it as follows:
^A sets the one-character flag (see below) then reads another
character and interprets it as if it had been typed after a ^].
^Q gobbles another character and returns it to TECO superquoted
(i.e. It will not act as a text terminator, in a search string,
it will have no special effect, etc.)
^R is the beginning of the name of a q-reg to be substituted.
^S cause the superquote flag to be turned on (see below) then read
another character as in ^A
^T cause the delimiter flag to be turned off (see below) then read
another character as in ^A
^V followed by a q-register name, causes the char whose ASCII
value is in that q-register as a number to be substituted in.
That is, after ^^AU0, ^]^V0 will substitute an "A".
^X reads a string argument to the M command that called the
current macro, and substitutes it in. ^]^X pushes the current
command buffer onto a special pdl, then causes the normal macro
pdl to be popped one level (the macro pdl is pushed onto each
time an M command is executed. It is also pushed onto by
^]<q-reg name> (see below)). TECO will then proceed normally,
reading from what is essentially a string argument to the
current macro, until an altmode is encountered. This altmode
will not be passed to TECO, but will instead cause the command
buffer to be repushed on the macro pdl and the special pdl to
be popped, thus restoring the state of the world. If a real
altmode is desired in a string argument, ^]$ (dollar sign)
should be used. If TECO had been in any state other than read-
ing commands (e.g., reading a string to be inserted) then the
characters read in the string argument will be protected from
being taken as text delimiters. Thus I^]^X is guaranteed not
to terminate somewhere in the macro argument. If this is for
some reason undesirable, a ^T (see above) should be used
between the ^] and the ^X (^]^T^X). Characters are not normal-
ly protected from being interpreted specially in searches, etc.
If this is desired, use ^S (eg. ER^]^S^X bar will cause the
file <macro argument> bar to be selected for read, even if the
macro argument has spaces, semicolons, etc. in it.). If the
one character flag had been on only one character will be read
as an argument instead of an entire string.
^Y acts like ^]^X, but only one character is taken from the previ-
ous command level. Has the same effect as ^]^A^X. Additional
^] calls will be chained through, with the final character com-
ing from the last command level not indirected.
^[ (altmode--usually printed "$")
pass a superquoted altmode back to TECO (same as ^]^Q )
^] pass an actual ^] to TECO
" pass a superquoted doublequote back to TECO.
$ (dollarsign)
pass an ordinary altmode back to TECO (see ^X above)
. is the beginning of a q-reg name. Multi-character q-regs such
as Q..A can be substituted with ^] just like single-character
q-regs.
0-9 the current command stream (executing macro) is saved and TECO
begins reading command characters from the contents of the
specifed q-register 0-9. After all of the characters in that
q-register, which must contain a string or buffer, have been
read, reading of the macro which contained the ^] itself will
resume. Delimiter protection and superquoting are handled as
for ^]^X. For example, I^]1 is equivalent to G1 (Note: G1 is
optimized to be much faster than I^]1), because any altmodes
in the string in q-register 1 will be delimiter protected so
that they do not terminate the I command. S^]1 will search
for whatever string is in Q-register 1. Altmodes in the string
will not end it, but ^B, ^N, ^O, etc. will have their normal
special functions. S^]^S1 superquotes the string and makes
even those characters behave like ordinary ones. The contents
of the q-register are saved so that storing into the q-register
while they are being read does no harm.
@ @ ("indirect") causes the characters substituted in by the ^]
to be treated as if they in turn had a ^] in front of them.
Thus, after :IA.B, ^]@A will substitute q-reg .B. After
:IA.Bfoo, ^]@A will substitute the contents of .B, followed by
"foo". I may change that if I can see an easy way.
A-Z like 0-9 (insert q-reg)
^^<char>
(ctl caret) has the value of the 7-bit ASCII code for <char>.
^_ (Note that in order to type this character to a program, it must be
typed twice, due to ITS hackery.) Ends execution of the command string
"successfully"; the TECO will log out if disowned, or return to its
superior if a ^C ended the typed-in command string. Otherwise, or
after TECO is P'd, TECO will reset all stacks (if FS *RSET is 0),
then maybe display the buffer or directory (using the user's supplied
macros in Q..B and Q..G if any), and go on to read another command
string. It is not wise to use this as a nonlocal exit from a macro;
that is what F< is for. The main use is to restart TECO's command
reading loop at the current stack levels--useful when a user-defined
error handler wants to transfer to a TECO break loop. TECO's command
loop puts a ^_ at the end of every command string to make sure that it
gets control back when the command string terminates. Otherwise, in a
break loop, control would return right back to the suspended program.
(Space)
Spaces around arithmetic operators are ignored. Spaces between two
values in lieu of an arithmetic operator count as a "+", except that
spaces by themselves before a command that can use an argument do not
count as an argument.
!<label>! defines <label> for use by O command (q.v.).
This contruct is also the standard way of putting comments in TECO
macros. It is ignored in execution. However, quotes and angle
brackets inside the label are counted when quotes are being balanced in
a conditional or angle brackets in an iteration. This is useful,
because if the commands in a conditional need to have unmatched quotes
you can put in matching quotes inside a label to make the whole thing
balance. The same is true for unmatched brackets in an iteration. For
example:
Q1"N !"! FTYou're losing'
or < Q1; EDFOO < !>! >
" starts a conditional. The character after the " gives the condition.
It is followed by conditionalized commands, up to a matching '. If an
else-clause is desired, the ' should be followed immediately by "#,
with perhaps CRLFs, spaces, or comments (see "!") in between, followed
by the contents of the else-clause, followed by another '. A condi-
tional may return a value. The conditionalized commands must be
balanced as to quotes. If some commands contain unmatched quotes,
place extra quotes inside a label (see "!") to balance them out.
The argument to the conditional is normally gobbled up by the condi-
tional, and the first conditionalized command receives no argument; see
F" for a variant conditional that passes the argument along instead.
FS STEPMAC will be processed on entry to a successful conditional.
The conditions that now exist are:
Char: Condition succeeds if numeric arg to " is
A the ASCII code for an alphabetic character.
B the ASCII code for a delimiter character
C the ASCII code for a non-delimiter character.
D the ASCII code for a digit.
E zero.
G positive.
L negative.
N nonzero.
U the ASCII code for an "upper-case" character (anything other
than 140 through 176 octal).
Any condition can be reversed with a ":"; thus, 0:"E fails.
The delimiter characters are those characters which are specified as
delimiters by the contents of q-reg ..D. Initially, q-reg ..D is set
up to specify that all non-squoze characters are delimiters, but the
user can change that by setting q-reg ..D. Squoze characters are
letters, digits, ".", "%" and "$".
Conditionals operate by skipping the text up to the matching ' if they
fail, and doing nothing if they succeed. If the ' terminating a fail-
ing conditional is followed by "#, they will be skipped as well. If
the conditional succeeded, they would be executed--and "# is really a
conditional that always fails.
A special kind of conditional that returns a success or failure code
can be obtained by putting a ' after the ", as in "'E. This kind of
conditional does not skip any code. Instead, it just returns -1 for
"success" and 0 for "failure". Such conditionals are useful because it
is easy to AND or OR them together and then test the result. For
example, an expression whose value is the signum of the number in q-reg
0 is: Q0"'L-(Q0"'G)
# exclusive or (an arithmetic operator).
$ (dollar sign) the old lower-case edit mode:
"-1$" is the same as "-1F$/" (first dollar, then altmode).
"0$" is the same as "0F$" (first dollar, then altmode).
"1$" is the same as "1F$".
For more info, see the "F$" command (that's dollarsign, not altmode).
%<q> increments the number in q-reg <q> by 1, and returns the result as a
numeric value. Meaningless if the q-reg contains text.
& logical and (an arithmetic operator)
' terminates a conditional (see "). This character is actually a no-op
when executed. It is for the " to search for if the condition fails.
(,) fill usual role of parentheses in arithmetic calculations. However,
they are more general in that not merely arithmetic operations but
arbitrary commands can be enclosed within them. The value within the
parentheses is simply the value returned by the last command before the
close. If the open was preceded by an arithmetic operator, arithmetic
is immediately done on that value. Otherwise, the close merges the
values from inside the parentheses with the values saved by the open.
Thus, 1,(2) and 2(1,) are both equivalent to 1,2. The colon and atsign
modifier flags are also merged in that the open saves them and clears
them, and the close restores and merges them: they will be on after
the close if either they were on before the close or they were on after
the open.
Parentheses can also be used where a q-register name is called for; the
value returned by the last command before the close is used as the
"contents" of the q-register. This construct is allowed only with
commands that only examine the q-register, not with commands that store
into it (since there is no place to store into). See the Q command for
this. See also F( and F) for variants of these commands.
* multiplication (an arithmetic operator). Note that in TECO there is no
operator precedence. Evaluation of arithmetic operators is left-to-
right.
+ addition (an arithmetic operator).
, separates arguments for commands taking two numeric arguments. Doesn't
affect the colon and atsign flags.
- subtraction (an arithmetic operator).
. equals the number of chars to left of the pointer.
..n Q-registers
..0,..1,..2
"^P" sort puts its 3 arguments into these q-regs. These q-regs are
also used by "F^A".
..A holds the string to be used to represent the cursor in standard buffer
display. Initially "/\" on displays, "^A^B" on Imlacs (looks like an
I-beam), and "-!-" on printing terminals (of course, TECO's default is
not to display the buffer on printing terminals unless FS TTMODE is
set). In the cursor, backspaces always really backspace and all other
control characters are treated as non-spacing characters.
..B holds the user buffer display macro. After each command string whose
last command was not an E-command, TECO does "normal buffer display",
as follows:
If ..B is 0, as it initially is, the default is: on graphics devices,
do "standard buffer display"; on printing terminals, do so only if FS
TTMODE is set; otherwise do nothing. For details of standard buffer
display, see "@V".
If q-reg ..B is nonzero, TECO simply macroes it. Normal buffer display
in this case consists of whatever that macro happens to do.
Q-reg ..H and flags FS ERRFLG and FS ERROR will contain information
about the command string that just ended. If either Q..H or FS ERRFLG
is nonzero, there is text on the screen that should not be immediately
covered over. The buffer display macro should check ..H and not dis-
play if it is nonzero. FS ERRFLG need not be checked, since if -1, it
will automatically cause all typeout on the first line of the screen to
be ignored on displays. This is the right thing if the buffer display
macro doesn't wish to worry about errors. If it is desirable to write
on the first line and overwrite the error message, just zero FS
ERRFLG.
..D holds the delimiter dispatch table, which tells several commands how to
treat each of the 128 ASCII characters. These commands are FW, FL, "B,
"C and the special search character ^B. The treatment of the character
with ASCII code <n> is determined by the values of the characters in
positions 5*<n>+1 and 5*<n>+2 in the delimiter dispatch table.
The first of the dispatch characters says whether the character <n> is
a delimiter. The dispatch character should be " " for a delimiter and
"A" otherwise. This dispatch character is used by FW, "B, "C and ^B.
The second dispatch character describes the character's syntax in LISP.
The possibilities are "(", ")", "/", "'" "|", " ", "+" and "A". Each
says that the character <n> should be treated by FL and @FW as if it
were an open, a close, a slash, etc. "+" is treated the same as "A" by
the FL command. The distinction between "A" and "+" is there to be
used by certain TECO programs.
Initially, the first dispatch character is "A" for squoze characters
(letters, digits, "$", "%" and "."), and " " for all others. The
second dispatch character is set up to reflect the default LISP syntax
definitions as closely as possible.
The delimiter dispatch must be at least 640 characters long so that
every character has a dispatch entry. ..D should always contain a
buffer or a string; if it holds a number an error will result.
..E holds the output radix for = and \. Initially decimal. Negative
radices work--somewhat. If the radix is 0 or 1, the next attempt to
use it will change it to decimal and also cause an error "..E".
..F holds the ^R secretary macro. If nonzero, it will be macroed every
(FS^RMDLY) characters while ^R mode is in use. More precisely, the
counter FS ^RMCNT is decremented each time through ^R's main loop, and
if it becomes 0, it is reset from FS ^RMDLY and ..F is macroed. ..F
is also macroed whenever the outermost level of ^R mode is exited (but
not when inner recursive invocations of ^R are exited). When ..F is
macroed because ^R is being exited, the FS ^RMODE flag will be 0;
otherwise it will be nonzero. If you are using ..F to save the buffer
in a file, then when you temporarily bind the buffer or put strange
crud in it, you should also bind ..F to 0 to prevent the buffer from
being saved while it is meaningless. Do not bind FS ^R MDLY, though;
then, if the time to run ..F comes up while in this state, TECO will
make sure to run it as soon as it becomes nonzero again.
..G holds the user-specified directory-display macro. Whenever TECO wants
to display the directory in the usual manner (that is, when ^U or E^U
is executed or at the end of a command string whose last command was an
E-command), if this q-reg isn't zero TECO will simply macro it (other-
wise, TECO has defaults--see "^U"). When that is done, q-reg ..H will
contain useful info.
..H is the "suppress display" flag. It is set to zero at the start of each
command string, whenever the screen is cleared. It is set nonzero when
any typeout or display takes place, except for error message typeout.
TECO's default is not to display the buffer if this q-reg is nonzero at
the end of the command string. User buffer and dir display macros
should also look at this flag. If ..H is nonzero on entering or
returning to ^R, ^R will wait until a character is typed in (and
executed, unless it is a space) before allowing any redisplay.
..I at the start of each command string, .'s value is saved in this q-reg.
At the end of each command string, Q..IFS PUSHPT is done. Those
actions are what enable the ^V command to work.
..J initially 0, if this q-reg contains a string that string will appear on
the screen just above the echo area, on the same line that --MORE--
sometimes appears on. The --MORE-- will still appear, following the
..J string, if it is appropriate. The displayed string is not updated
immediately when ..J is changed, but rather at the next opportunity for
redisplay of the buffer or the next time typeout reaches the bottom of
the screen. It is possible to put a buffer in ..J but that has the
problem that TECO will not always be able to detect it when the buf-
fer's contents change, and thus will not be able to update the screen
when it should. If the string in ..J is too long, it is truncated to
make sure that the --nn%-- or --MORE-- can fit. If recomputing ..J
when you want it to change is too inconvenient, you can arrange for ..J
to be recomputed when it is about to be displayed. See FS MODE
CHANGE.
..K each ^K or ^W command in ^R mode puts the deleted text in this q-reg so
it can be reinserted if desired.
..L whenever TECO is started, this q-reg is executed. Also, after an EJ,
the macro loaded into ..L is run. When a TECO dump file is made with
@EJ, ..L should contain a macro to do whatever must be done when the
file is loaded back in. However, since that macro would be re-executed
if TECO were G'd afterward, it should replace itself with something
innocuous that just resets the terminal-related flags.
If a ..L macro can exit, it should do so with a ^_ to start up the TECO
command reading loop. A CNM error will occur if the ..L macro tries to
return any other way. ..L should no longer be used for resetting
terminal-type-dependent options. Use FS TTY MACRO for that.
..N This q-reg is special in that whenever it is popped by automatic
unwinding of the q-register pdl, the previous contents are macroed
after the pop. Thus, it is possible for a macro to set up an action
that will be performed when the macro is exited, no matter what causes
it to be exited, by pushing Q..N and putting the commands for that
action in Q..N. For example,
[0 .U0 [..N :I..N Q0J
saves . in such a way that it will always be restored. That string,
unfortunately, has a timing error in that a ^G-quit after the [..N will
find an inconsistent state. The remedy is to use the FN command which
is the same as "[..N:I..N":
[0 .U0 FN Q0J
Within a macro that has already set Q..N up in this way, the easiest
way to add another action to be performed is to append to ..N using
:I..N^]^S..N<new-stuff>. Note that popping Q..N explicitly with ]..N
does not macro it. If you wish explicitly to pop ..N and macro the old
value, the way to do it is "-FS QPUN". "M..N]..N" has the disadvan-
tage that when ..N is executed it is still on the q-reg pdl; that may
make it execute improperly and also is a timing error.
..O this q-reg is defined to hold the current buffer. That is, all the
commands that use "the buffer" use whatever buffer happens to be in
Q..O at the time. An attempt to put a string or number in Q..O causes
an error.
..P holds the user-defined error-handler macro, if any. Whenever an error
occurs that is not caught by an errset, this macro will be invoked. If
it is 0, TECO will instead print out the error message and set up for
"?" in the normal manner. The executing command string will have been
pushed on the macro pdl, so FS BACKTRACE can be used to examine it.
Also, the arguments will have been saved with "(" so that they can be
examined with ")F(=". FS ERROR will contain the error code for use
with FE or FG in obtaining the error message. Note that the error
handler is invoked for quits and when TECO is restarted, as well as
after errors; at those other times FS ERROR will be zero. If the
error handler prints an error message in the main program area of the
screen, it may wish to allow buffer display to occur as usual but
prevent the error message from being overwritten by it. Setting Q..H
to zero permits buffer display, and setting FS ERRFLG to minus the
number of lines of error message preserves them. The FG command takes
care of this automatically.
The error handler can return to the erring program with ")^\" or "F)^\"
(return whatever you like, but make sure to close the parentheses
somehow). However, do not expect the command that signalled the error
to be retried.
To abort the entire computation which got the error, the correct thing
to do is FS ERR THROW. This will return to the innermost error catch
(:@< ...>) or ^R level. If there is none of those, it will return to
the top level of TECO. You may also use F; to return to a catch that
was made at a higher level, or use ^W to pop out to TECO's top level
loop.
To make a break loop, just do a ^_ which will transfer to TECO's
command string reader.
If an error happens while the error handler is being entered, in order
to prevent an infinite error loop TECO does an automatic ^W command to
pop all stacks and prints "error entering error handler". Stack
overflow for any reason is likely to cause this since the error handler
requires stack. Any error in the error handler is likely to cause a
series of recursive errors, fill the stack, and cause this response.
..Q holds a q-vector which serves as the symbol table for TECO variables,
such as QFoo accesses. The symbol table is in the format that FO
likes. Initially, the q-vector in ..Q has only one element, which
contains 2, the default number of words per symbol table entry. See FO
and Q for more details.
..Z initially holds the same thing as ..O (the initial buffer), on the
assumption that your main editing will be done in it, so that if you
accidentally leave something else in ..O you can do Q..ZU..O to recover
and not lose all your work.
/ division (an arithmetic operator).
0-9 a string of digits is a command whose value is a number. If it is not
followed by a ".", the normal input radix (the value of FS IBASE,
initially 8+2) is used. If the number ends with ".", the radix used is
the value of FS I.BASE, initially 8. An attempt to type in a number
too large for a 36-bit word to hold will cause a "#OV" error, unless
the radix is a power of 2.
: used before certain commands, modifies function of that command in a
way described separately for each such command. Arithmetic operators
and comma do not affect the colon flag. Parens save it just like
arguments, and don't deliver it to the commands inside the parens.
Commands that don't return values always turn it off; commands that do,
either ignore it or use it and turn it off.
; does nothing if arg<0. Otherwise sends command execution to char after
next > (see < description). If no arg, uses value returned by last
search (see S) as arg.
:; like ;, but with the opposite condition: end iteration if arg is <0,
or last search succeeded.
@; like ;, but exit iteration if arg is EQUAL to zero.
:@; like ;, but exit iteration if arg is NOT EQUAL to zero.
< begin iteration. Commands from here to the matching > are executed
over and over, until a ; command decides to exit the iteration. It
does so by scanning forward, counting <'s and >'s seen, until an
unmatched (since the ;) > is passed. Because of the way ; works,
commands inside iterations following a ; must be balanced as to angle
brackets. If a command contains an unmatched bracket, you can use an
opposite bracket inside a label to balance it out. Within the
iteration, the sequence !<!> can be used to mean "jump to the beginning
of the iteration." The !<! is needed to avoid confusing any ; commands
earlier in the iteration. It is an error if the iteration remains
unterminated at the end of the macro level it began on. Within
iterations, failing searches do not cause errors, unless FS S ERROR is
nonzero (as it is in EMACS) to disable this "feature".
<n>< iterates <n> times (or until a ; command exits). The !<!> construct
must not be used in such an iteration since, if the count has run out,
it will not do its job. Use !<!@> if you want to jump to the beginning
without decrementing the count.
<m>,<n><
ignores <m>.
:< begin errset. This is like < except that errors occurring inside it
are caught and will return after the >. TECO will not print any error
message nor run the error handler in ..P. Instead, the error message
string will be returned as the value of the ">" which ends the errset.
If the errset returns normally (no error) the value is 0. The
canonical application for errset is 1:< EDFOO BAR > which deletes FOO
BAR if it exists but avoids any problem if the file does not exist.
TECO's built-in error messages all start with a 3-letter code that says
what kind of error it is; use a F~ to compare the error message string
against a specific prefix.
Note also that :< iterates like <. Perhaps you want "1:<"? Errsets do
not prevent failing searches from erroring (luckily), and prevent any
iterations outside them from doing so. An iteration inside an errset
will still prevent searches from erroring inside it despite the errset.
Of course, to really win, you should set FS S ERROR. An errset has no
power through a call to ^R or through an error catch (:@<). The
innermost errset, ^R, or error catch is what determines how an error
will be processed.
:@< begin error catch. An error catch specifies a place for control to
return to after an error has been processed (error message printed or
error handler in ..P run). It differs from an errset (:< with no @) in
that the errset grabs control without letting the error message be
printed. The canonical application for an error catch is in a command
loop which allows the user to give many different commands. An error
in one of the commands should be reported as usual, but the error
should not cause the command loop to be exited. Every call to ^R
implicitly contains an error catch. Note that :@< iterates just like
<. If you want it to execute only once, do 1:@<. The command FS ERR
THROW is a way to return control to the innermost error catch (where
^R levels count as error catches). The value returned by the error
catch will be 0 if it was exited normally, by falling through the end.
If FS ERR THROW was used to exit, then the value will be the argument
given to FS ERR THROW.
= is for printing numbers:
<n>= types out <n> in the current output radix, and a CRLF. The output
radix is kept in q-reg ..E . It is initially 8+2.
<m>,<n>= types both <m> and <n>, with a comma between.
:= is like = but omits the CRLF.
@= is like = but types in the echo area. @:= also works.
> end of iteration, errset or catch (see "<", ":<", "F<").
@> end of iteration, etc., except that the iteration count is not
decremented. !<!@> is a good way to jump back to the beginning of the
iteration without decrementing the count.
? if this is the first char input after typeout of an error message from
TECO several command chars before the one causing the error will be
typed. Otherwise, enter trace mode, or, if in trace mode already,
leave trace mode. When in trace mode all command chars are typed out
as they are executed. Trace typeout never uses the first line so that
error messages won't wipe it out. The flag FS TRACE is nonzero when
in trace mode.
:? leaves trace mode whether in it or not.
@ is a modifier command which alters the action of the following command
(except for a few commands which ignore it and pass it on to the next
command). Many commands which take string arguments interpret the @
modifier to mean that the first character after the command should be
used as the string delimiter, instead of Altmode. But not all string
argument commands do this, so you must check the individual command.
The older form of the @ command is the ^ command, so most old TECO
programs will contain ^ instead of @. ^ was changed to @ because it
could be confused with control characters.
A if no arg, append next page of input file to current contents of
buffer, i.e., like "Y" only don't empty buffer first. If virtual
buffer boundaries are in use, the appended text goes just below the
upper virtual boundary. Does not close the input file.
<n>:A appends <n> lines of the file (but won't append beyond page boundary).
Uses the same conventions for throwing away padding as "Y" does. Does
not close the input file.
@A appends all the rest of the file. A cross between "A" and "@Y".
Closes the input file.
<n>A value is the 7-bit ASCII value of char arg chars to the right of the
pointer. Note that "0A" is the character immediately to the left of
the pointer and "-<n>A" is the character <n>+1 characters left of the
pointer. If .+<n>-1 is not within the bounds (real or virtual) of the
buffer, a "NIB" error occurs.
<m>,<n>A
is like <n>A except that when <n>A would cause a "NIB" error, <m>,<n>A
will return <m>. Thus, 13,1A will return 13 iff the pointer is either
at the end of the buffer or before a carriage return.
B normally 0. Actually, the number of the first character within the
virtual buffer boundaries--but that will be the first char in the
buffer (char number 0) unless you have used FS BOUND or FS V B to
change that.
C moves in the buffer relative to pointer:
<n>C move pointer <n> chars to the right (1 char, if no arg). If that's out
of the buffer, a "NIB" error results.
:C like C, but returns -1 ordinarily, or 0 if C without colon would cause
an error. :C is to C as :S is to S.
D delete arg chars to right of pointer. If arg<0, delete to left of
pointer.
"E" commands
E is the prefix for most operations on files.
E^U<dir>
displays in the usual manner the directory of the device specified in
the string argument, or the default device. More precisely, reads the
string arg and sets defaults, then does "^U".
E?<file>
tries to open <file>, and returns 0 if successful. Otherwise, the
value is the system error code which describes why the file cannot be
opened. In any case, the file does not stay open, and the open input
file if any is not interfered with. The file's reference date is not
set. If the device is USR:, the job will not be created if it does not
exist.
E_<old><new>
makes a copy of the file <old> and names it <new>. I/O is done in
ASCII block mode. The currently open input and output files are not
affected. :E_ is similar but transfers the date of the input file to
the output file. @E_ puts the real filenames of the input file into
the defaults before reading the output file name, making it easy to
preserve the version number.
EC close the input file, if any. This should always be done whenever an
input file is no longer needed; otherwise, one of the system's disk
channels will be tied up. @Y, EE and EX automatically do an EC. All
other input operations always leave the input file open.
ED<file>
deletes <file>.
:ED deletes the currently open input file.
@ED<file>
on Twenex, deletes and expunges <file>. On ITS, same as plain ED.
EE<file>
like infinity P commands then EF<file> and EC.
EF<file>
files output accumulated by PW and P commands with the name <file>.
<file> may not contain a device or SNAME; they must have been specified
when the file was opened (with EI or EW) and may not be changed.
:EF files the output without renaming the output file.
EG is a semi-obsolete command for getting random info. It inserts in
buffer on successive lines
the current date (as YYMMDD),
the current time (as HHMMSS),
TECO's current sname,
TECO's default filenames for E-commands,
the real names of the file open for input
the date in text form,
a 3-digit value as follows:
1st digit = day of week today (0 = Sunday)
2nd digit = day of week of 1st day of year
3rd digit should be understood as binary:
4-bit = normal year, and after 2/28
2-bit = leap year
1-bit = daylight savings time in effect.
(this line is blank on Twenex)
and the phase of the moon.
There are better ways to get most of these things: FS FD CONV, FS D
FILE, FS D SNAME, FS I FILE.
EI opens a file for writing on the default device. The filenames used
will be "_TECO_ OUTPUT". When the output file is closed, it will
normally be renamed to whatever names are specified. However, if the
TECO is killed, or another output file is opened, anything written will
be on disk under the name "_TECO_ OUTPUT_"
:EI like EI, but uses the current filename defaults instead of "_TECO_
OUTPUT". This is useful for opening on devics which do not support
rename-while-open fully, such as the core link. Use :EF to close the
file without renaming it.
@EI like EI, but opens an old file in rewrite mode if there is one, rather
than creating a new file in all cases. Together with FS OFACCESS and
FS OFLENGTH this can be used to update an existing file in arbitrary
ways. However, what you really want to use is:
@:EI like @EI but uses the default filenames rather than "_TECO_ OUTPUT".
EJ<file>
restores the complete environment (q-reg values, buffer contents, flag
settings, etc) from the specified file, which should be in the format
produced by @EJ. This restores all q-regs, buffers, and flags to what
they were when the file was dumped. Exception: pure (:EJ) space is
not changed, nor is FS :EJPAGE. After loading, TECO restarts itself,
which implies that if a nonzero value was loaded into Q..L, it will be
macroed. This is intended to be used in init files, for loading up
complicated macro packages which would take a long time to load from
source files. If the file isn't a dump file, or was dumped in a
different TECO version, an "AOR" error occurs.
@EJ<file>
dump all variable areas of TECO on the file open for writing (it must
already be open), and file it under the specified filenames. One
should not write anything in the file before doing "@EJ". Files
written with @EJ can be loaded into a TECO with the EJ command, or they
can be run as programs directly, in which case they will bootstrap in
all the constant parts of TECO from the canonical place: .TECO.;TECPUR
<TECO version>. They also contain indirect symbol table pointers to
that file, so that attempting to load the symbols of an @EJ'd file will
load TECO's symbols. If you @EJ a file TS FOO on your home directory,
then FOO^K will always get you that environment.
:EJ<file>
inserts the specified file into core, shareable and read-only, and
returns a string pointer to the beginning of it. :EJ assumes that FS
:EJPAGE points to the lowest page used by :EJ's, and inserts the file
below that page (updating the flag appropriately). Memory is used
starting from the top of core and working down to page 340. See the
sections "buffers - internal format" and "buffer and string pointers -
internal format" for information on what can go in the file.
An ordinary ASCII text file is not suitable for :EJ'ing. A file to be
:EJ'ed must, first of all, be a single string whose length (including
its header) must be a multiple of 5120 (1K words of characters).
Within that string live the other strings or whatever that are the data
in the file. Their format is unrestricted except that the first thing
in the file (starting after the header for the file as a whole) should
be a string which is the file's "loader macro" which must know how to
return the data in the file when asked for it. The loader macro should
expect to be called with the name of the desired data (as a string) as
the first argument (^X), and a pointer to the whole file (as a string)
as the second argument (^Y). The reason for passing it the pointer to
the file is so that the loader itself can be pure (independent of the
particular file containing it). The pointer to the file, plus 4, gives
a pointer to the loader itself, if the loader wishes to examine its
body. The loader macro should return as its value the string which is
the value associated with the specified name. If the name is undefined
in the current file, the loader should pass the request on to the
loader in the next file. The next file can be assumed to start right
after the end of the current one, so that ^Y+FQ(^Y)+4 is a pointer to
it. If there is another file, FQ of that will be positive; otherwise
(this is the last file in memory) FQ of that will be -1. If there are
no more files, the loader should return 0. The goal is that several
files with different loader macros should be :EJ'able in any order, and
yet allow things to be loaded out of any of them at any time.
EL display in the standard manner the directory of the default device.
This command does not use the user's buffer display macro; in fact, the
buffer display macro might well use this command.
EM insert in buffer file directory of the default device. On Twenex, any
pre-comma arg specifies don't include author name, and a post-comma arg
is passed to the JFNS call.
EN<old><new>
renames the file <old> to have the name <new>. The device and SNAME
may not be changed; they should not be specified in <new>.
EP<file>$
does ER<file>, then bigprints file name twice on device(s) open for
writing.
EQ<from><to>
creates a link named <from> pointing to the file <to>. devices COM:,
TPL: and SYS: are understood. (ITS only) An attempt to link to a
non-disk device is an error.
ER<file>
opens <file> for input. The "Y", "A" and "FY" commands in various
forms may be used to read from the file. As soon as the file is no
longer needed (eg, if all of it has been read), an "EC" should be done
to close the input channel. "@Y" and "EE" do an automatic "EC". FS IF
ACCESS, FS IF LENGTH, and FS IF CDATE make it possible to get or set
various parameters of the file.
<n>ER is similar but specifies open-mode <n> (actually, <n> IOR 2). <n>
should be even!! <n>=4 specifies image mode, which makes a difference
for file directories. This is only meaningful on ITS.
<n>,ER<file>
bits in <n> are interpreted as follows:
1: opens an input file and does not change its reference date. This is
defined to work on all operating systems.
2: opens an input file in "thawed" mode. This is probably only useful
on Tenex, where it allows multiple readers of the file.
4: (Twenex only) does not open the file at all, just does a GTJFN.
FS IF CDATE, FS IF NAME, and FS IF FDB can still be used, though.
ET<file>
sets the default filenames to <file>.
:ET (Twenex only) does a GTJFN reading from the terminal, to provide file-
name completion, etc. The numeric argument is the left-hand flags for
the GTJFN. The flag FS :ET MODE controls which filenames' default
values are provided for the GTJFN. The pre-comma argument is the
prompt string; on Tops-20 this is used for setting up a call to the
COMND JSYS. On Tenex, it is simply typed out in the echo area; so this
is the correct way to prompt when reading a filename.
EW<dir>
like EI but device specified by following text string rather than by a
numeric arg.
:EW<file>
like EW, but uses the specified filenames instead of "_TECO_ OUTPUT".
This is useful for opening on devics which do not support
rename-while-open fully, such as the core link.
@EW<dir>
like EW, but opens an old file in rewrite mode if the file exists,
rather than creating a new file in all cases. Together with FS
OF ACCESS and FS OF LENGTH, this can be used to update an existing
file in arbitrary ways. However, what you really want to use is:
@:EW<file>
like @EW but allows filenames to be specified rather than using "_TECO_
OUTPUT".
EX<file>
(Twenex only) if a file is open for output, does EE<file>, then
instructs the EXEC to repeat the last CCL type command (load, execute,
compile, debug).
EY<dir>
like EL but specified device and SNAME. On Twenex, the entire string,
if provided, is used, including wildcards, for the GTJFN. Also, on
Twenex, a numeric argument specifies the JFNS format.
EZ<dir>
like EM but etc.
E[ push the input channel, if any. Saves the current input file and
position in it, or saves the fact that no file is open. Useful for
reading in a file without clobbering any partially read input file.
Note: for this and the next three commands ("E]", "E\", "E^"), the
file open for input must be randomly accessible (=DSK). The one open
for output need not be. FS PAGENUM and FS LASTPAGE are saved by E[
and restored by E].
E] pop the input channel. If any input file was open, the rest of it is
flushed. Further input will come from the file that was popped. (see
"E[".)
E\ push output channel. (see "E[".)
E^ pop output channel. If an output file is open, it is closed without
being renamed, so it is probably filed as "_TECO_ OUTPUT". (see "E[".)
"F" commands
F further decoded by the next character as follows:
F^@:
<m>,<n>F^@
returns 2 values, which are <m> and <n> in numerical order. Thus,
"1,2F^@" and "2,1F^@" both return 1,2. "<m>,<n>F^@T" is the same as
"<m>,<n>T" except that the former will never cause a "2<1" error.
<n>F^@ returns, in numerical order, 2 args that delimit a range of the buffer
extending <n> lines from the pointer. Thus, "<n>F^@T" is the same as
"<n>T".
<n>@F^@
is like <n>F^@ but treats in CRLFs, not just CRs.
F^A:
<m>,<n>F^A<q>
this command scans the range of the buffer from <m> to <n> using the
dispatch table in q-register <q>. That is, each character found in the
buffer during the scan will be looked up in the dispatch table and the
specified actions will be performed. The dispatch table should be a
string or buffer with at least 128*5 characters in it--5 for each ASCII
character. Each character seen has its ASCII code multiplied by 5 to
index into the table, and the 5 chars found there are executed as TECO
commands. When that is done, the char that was found in the buffer is
in Q..0 as a number, point is after the character if forward, before if
backward, Q..3 holds the dispatch table that was in use (so that the
dispatch commands can change it if they wish) and Q..2 holds the end of
the range to be scanned. For forward scans, it is in the form of the
distance between the end of the range and Z; for backward scans, it is
the distance between the end of the range and B. Thus, deleting or
inserting characters never requires changing Q..2. The use for chang-
ing Q..2 is moving the end of the range--for example, stopping the scan
early (do ZU..2). Nothing forbids the macro to change point--that is a
fine way to skip over characters that are "quoted" by others.
For efficiency, if the first of the 5 chars in the dispatch table is a
space, the 5 are not macroed. Instead, the second character, minus 64,
is added into Q..1, and the third is specially decoded. " " means no
action; this feature makes to easy to skip over most chars, keeping
track of horizontal position. Other permissible third characters are
"(" and ")". Their use is in counting parens or brackets. "(" means
that if the scan is backwards and Q..1 is positive, the scan should
terminate. ")" means that if the scan is forward and Q..1 is negative,
the scan should terminate. If an open-paren-like character is given
the dispatch " A( " and the close is given " _) ", the same dispatch
table may be used to find the end of a balanced string going either
forward or backward. "F^A" may be given 0 or 1 arg--it turns them into
2 the way "K", "T", etc. do.
<m>,<n>@F^A<q>
the atsign modifier causes the scan to go backwards.
<m>,<n>:F^A<q>
scans like F^A but expects its dispatch table to be a q-vector contain-
ing string pointers. As with ordinary F^A, to each ASCII character
there corresponds a word of the dispatch table, but this word should
normally contain a pointer to a string to be executed when the charac-
ter is seen. Thus, you can macro strings longer than 5 characters
without having to use up lots of q-registers to hold them. Alterna-
tively, the dispatch table word may contain five characters starting
with a space, which are interpreted as in an ordinary F^A. Thus,
simple characters that need only to be skipped over are no slower than
in an ordinary F^A. The use of q-registers ..0, ..1, ..2 and ..3 is
just like that in ordinary F^A.
F^B:
<ch>F^B<string>
searches for the character <ch> in <string>. <ch> should be the ASCII
code for a character. If that character does not occur in <string>, -1
will be returned. If the char does occur, the value will be the
position of its first occurrence (eg., 0 if it is the first char).
<pos>,<ch>F^<string>
is like <ch>F^B but searches starting at position <pos> in the string.
If no occurrence is found past there, the value is -1.
@F^B<string>
searches the buffer from point forward for a character NOT belonging to
<string>, and then returns .,<address of that character>. If such a
character is not found, .,Z is returned.
-@F^B<string>
searches the buffer backwards from point for a character NOT belonging
to <string>, and then returns <address of that character>,<point>. If
no such character is found, B,. is returned.
<x>,<y>@F^B<string>
searches the buffer from <x> to <y> (which can be either forward or
backward) for a character NOT belonging to <string>, and then returns
.,<address of character> or <address of character>,., whichever puts
the smaller value first.
@:F^B<string>
is like @F^B with no colon except that it searches for a character
which IS a member of <string>. It takes the same sorts of arguments
that non-colon @F^B takes, and returns the same sorts of values.
F^E<string>
replace <string> into the buffer at point. Replacing means inserting,
and deleting an equal number of characters so that the size of the
buffer does not change. The advantage of this command over "I<string>
FKD" is that the gap need not be moved.
<n>F^E<string>
replaces <string> in at <n>. Point does not move. Like ".( <n>J
F^E<string> )J".
<n>:F^E<q><string>
replaces <string> into the string or buffer in q-reg <q> starting at
the <n>'th character. This is the only way that the actual contents of
a string can be altered, although other commands copy pointers to
strings, or create new ones. If this command is done, it may be
necessary to sweep the jump cache (see "F?") if the string being
altered might be a macro that might contain "O" commands.
F^F: F^F is the forward-only S-expression parser.
<s>,<e>F^F
parses LISP s-expression from the starting value of point to address
<e>, assuming that the state at the starting point is <s>, and returns
the state at the ending point, leaving point there.
A "state" includes all the essential information about the surroundings
of a given spot in a LISP expression. Its right half is the depth in
parentheses. Its left half is made up of several bits:
100,, => this spot is inside a comment.
4,, => this spot is between vertical bars.
2,, => the preceding character is an atom constituent or slash, or
is slashified, and we're not in a comment.
1,, => the following character is slashified.
Usually it is fine just to use zero for all the bits. Using a negative
number as an initial state specifies a negative paren depth and makes
all the bits zero.
Several Q-registers are set up on return:
Q..0 receives the address of the last comment-start or vertical-bar
open encountered. It is useful when you find that the ending point
is inside one or the other.
Q..1 receives the address of the last unmatched "(", or -1 if there
was none encountered.
Q..2 receives the address of the start of the last complete
s-expression (ie, its termination was passed), or -1 if no
s-expression begun has terminated.
Scanning stops either at address <e>, or when the parenthesis depth
becomes zero. Aside from this termination condition, the depth is used
only as a relative quantity, so you can choose the initial depth to
obtain the desired termination condition, or make it far away from zero
to disable the feature.
To use F^F to move forward, choose an initial parenthesis depth that
will make it stop at the appropriate place. To use F^F to move back-
ward, go to the beginning of a top-level s-expression, or the beginning
of the buffer, and scan forward to the point you are trying to move
from. The value in Q..1 or Q..2 will tell you where to move to. To
determine whether a line has a comment on it, scan from such a known
point to the end of that line (before the CRLF). When the F^F returns,
it will tell you whether that point is inside a comment. If it is,
Q..0 will address the semicolon.
:F^F is like F^F, except that it stos scanning if it passes the start of an
atom. It also stops when plain F^F stops. It is useful for such
things as making sure that an F^F doesn't run away from you because
there was a very long s-expression where you expected an atom.
F^G:
<m>,<n>F^G<q>
Performs a local variable value swap on an EMACS-format buffer table
<q>. <m> should be the index in <q> (in words) of the entry whose
local variable values are to be swapped. <n> is the offset within the
entry of the first local variable. The number of local variables is
determined from the length of the entry, which is the first word of the
entry. Each local variable is described by two words: the first is
the name; the second, the swapped-out value (the global one, for the
selected buffer; the local one, for other buffers). The name of a
local variable is either a string, for a QFOO-type variable, or the
:FSQPHOME of a short-name q-register or ^R-mode character definition
or FS flag.
Each swapped-out value is exhanged with the value cell of the variable,
found by looking the name up in q-reg ..Q if it is a string, or by
using it as an address if it is a number. A number must represent a ^R
character, a q-register, or an FS flag. Suitable numbers can be
obtained by pushing the location involved and then looking at -1:FS QP
HOME: [A -1:FS QP HOME( ]A) returns the address of q-register A;
[^^@ -1:FSQP HOME( ]^^@), that of the definition of ^@; F[^R REPLACE
-1FS QP HOME(F]^R REPLACE), the code for FS ^R REPLACE. To turn
such an address into a string containing the name of the q-register,
use @FS QP HOME.
The @ and : flags make F^G transfer data only onw way instead of swap-
ping. @F^G copies the current values into the local symbol table, but
does not change the current values. :F^G copies from the local symbol
table setting the current values.
F^K<prompt>
is a command that reads a string argument. If the current macro was
called by another macro, without the @ flag (see @), the string
argument is read from the caller as if by ^]^X. In this case, the
<prompt> is ignored. If the current macro was run as the definition of
a ^R-mode character, or was called with the @ flag to pretend that it
was called directly by ^R, the string argument is read by doing M*F
Hook*. The <prompt> string should be read as an argument by that
macro, which the user is responsible for defining. In addition, F^K
can be given one or two numeric arguments which will be passed on to
*F Hook*.
In either case, the string argument is returned as a string object as
the value of the F^K command. If you like, you can make the *F^K Hook*
macro exit the macro containing the F^K in the event that the user rubs
out past the beginning of his argument. This can be done with -3 FS
BACK RETURN.
:F^K can be used by a macro to tell whether it was called from the internals
of TECO or from another macro. It returns -1 if the macro was called
from the internals of TECO or was called with @M. Otherwise, it
returns a positive number.
F^R reports to ^R that completely unknown changes to the buffer have taken
place, and that ^R should not assume that any of the information it
remembers from previous display is still valid.
<m>F^R is a no-op, to round out F^R with zero or two args, so that you can
pass to F^R any args you might have returned to ^R, with equivalent
results.
<m>,<n>F^R
reports to ^R that the range of characters <m> to <n> has changes made
in it, and needs to be redisplayed. This is like doing <m>,<n>@V
except that F^R never actually does the redisplay; it just causes it to
be done at the next opportuntity. F^R should not be used unnecessar-
ily. For example, once a macro uses F^R, it cannot be used on any
buffer except the one the next ^R up is displaying.
<m>,<n>@F^R
reports to ^R that screen lines <m> through <n>, not including <n>,
need redisplay. This is used for exiting minibuffers. It is very
important that the text previously displayed on line <n> be unchanged
in the buffer and still belong on that line.
:F^R asks ^R to verify that the window in FS WINDOW is still valid, and
choose a new valid one if it isn't. This operation is extremely fast
when the window is still valid, because it assumes that FS ^R VPOS is
up to date. If you want it to assume nothing, do a plain F^R first.
Normally, the previous window is kept if it is still valid. To insist
on re-centering point, do -1FS WINDOW first to flush the old window.
<n>:F^R
asks ^R to choose a new window putting point on line <n> of the window
area. <n> is relative to FS TOPLINE. The old window is never
re-used. FS ^R VPOS is not depended on.
@:F^R is like :F^R, except that on a terminal with insert/delete line capa-
bility ^R will attempt to move text on the screen IMMEDIATELY so as to
optimize redisplay later. The number of lines up or down to move the
text is determined by assuming that FS ^R VPOS is valid.
<n>@:F^R
is like <n>:F^R, but moves text on the screen if possible.
F^S:
<m>,<n>F^S<q>
searches the buffer or word aligned string in <q> for a word containing
<n>, starting at word <m>. If one is found, its index is returned;
otherwise, -1 is the value. The index of one occurrence can be used as
<m> in the next call to find the next occurrence.
<m>,<n>:F^S
searches the ^R character definition table instead of a buffer. In
other respects it is like F^S.
F^X within a macro, this command returns as its values the arguments that
were given to the macro. As many values are returned as args were
given. To find out how many there were, use F^Y.
F^Y returns a value saying how many args it was given. For example, WF^Y
returns 0; W1F^Y, 1; W1,F^Y, 2; W1,2F^Y, 3. The : and @ flags are also
indicated by bits in the value; :F^Y returns 4 and @F^Y returns 8.
1,2:@F^Y returns 15. The modifier flags, and the previous arguments,
are flushed.
F^^<^R-char>
F^^ takes the name of a ^R-character definition, as a q-reg, and
returns the 9-bit character code for the character. For example,
F^^.^R. returns the code for Control-., which is 256 octal.
<string>:F^^
:F^^ is used to test whether a string contains a valid short q-register
name. The string is passed as a string pointer in a prefix argument.
If the string contains a short q-register name then the :FS QP HOME of
that q-register is returned. Otherwise, zero is returned.
F"<condition>
F" is a conditional. It works like ", except that whereas " throws
away its argument after testing it, F" returns its argument, whether it
succeeds or fails. Thus, QA-QBF"LW'+QB implements max(QA,QB). (a
better way, though, is QA,QBF^@, before any command which ignores a
pre-comma argument).
F$ is used to read or set the status of case conversion on input and case
flagging on output, for terminals that do not have lower case. What
those features do when activated is described below. F$ controls them
thus: with no arg, returns the value of FS CASE and inserts in the
buffer before the pointer the case-shift char, if any, and the case-
lock char, if any. With an arg, sets FS CASE to that arg, and takes
a string argument whose 1st char becomes the new case-shift, and whose
2nd char becomes the new case-lock. (if the chars are the same it is
only a case-shift) (if there are no chars, you get no case-shift or
-lock, etc) the old case-shift and case-lock, if any, become normal
characters before the string arg is read. Thus, repeating an F$
command will not screw up.
Case conversion on input:
When FS CASE is nonzero, all letters are normally converted to the
standard case, which is upper case if FS CASE is positive; lower if
negative. The case-shift char causes the next char to be read in the
alternate case. The case-lock char complements the standard case
temporarily (it is reset for each cmd string). The case-shift quotes
itself and the case-lock. The "upper case special characters" which
are "@[\]^_" are not normally converted, but if one of them is preceded
by a case-shift it will be case shifted into a "lower case special
character" (one of "`{|}~<rubout>"). (note that case conversion
happens during command execution now, so that it makes sense to change
modes in the middle of a command string. However, no case conversion
is done on characters that come from macros) (note also that it doesn't
work well to have FS CASE and FS *RSET simultaneously nonzero, for
complicated reasons).
Case-flagging on output:
If FS CASE is odd, chars in the nonstandard case (and the "lower case
special characters") will be preceded by case-shifts on typeout from
the buffer. If FS CASE is even, no flagging is done.
F( is like ( except that whereas ( returns no values, F( returns its
arguments. F( therefore facilitates putting the same information in
two places without the use of a q-reg.
<n>F(<m>)
converts <n> feet <m> inches to inches.
F) resembles ), but whereas ) returns its arguments combined with the
values stored by the matched (, F) returns precisely its arguments.
The data saved by the corresponding ( is discarded.
F* reads and ignores a string argument. Useful in macros because
"F*^]^X" reads and ignores a string argument passed to the macro.
F+ clears the screen. Like "^L", but does not separate pages in files.
If only a part of the screen is in use (FS LINES or FS TOP LINE is
nonzero), only that part is cleared. To be sure to clear the whole
screen, bind both of those flags to 0 around the F+. On non-erasable
displays such as Tektronixes, this does clear the screen, even though
TECO does not otherwise treat such terminals as displays. On printing
terminals, a CRLF is typed.
F6<string>
returns a word of SIXBIT containing the first six characters of
<string>.
<sixbit>F6
interpreting <sixbit> as a word of SIXBIT, converts it to ASCII which
is then inserted in the buffer before the pointer.
<sixbit>: F6
returns a string containing the characters of <sixbit>. @F6 is an
obsolete equivalent command.
F;<tag>
is a "throw", a la LISP. See "F<" below.
F<!<tag>! ... >
is a catch. If anywhere in the arbitrary code which may replace the
"..." a "F;<tag>" command is executed, control will transfer to after
the ">" that ends the catch. If no "F;" is executed, the catch acts
like an iteration, so if the code should be executed only once, "1F<"
should be used. When a "F;" or throw happens, all macros, iterations
and errsets entered within the catch are exited and the q-reg pdl is
unwound to the level it had at the time the catch was entered.
Example:
F<!FOO! [A FIUA QAI QA-32"E F;FOO' ]A>
reads characters from the terminal and inserts them, up to but not
including the first space, and does not modify the q-reg pdl (never
mind that this macro might be improved). If a throw ("F;") is done to
a tag that does not belong to any catch containing it, an error "UCT"
occrurs, at which time nothing has been unwound. The ">" ending a
catch will return 0 if the catch was exited normally; if it was thrown
out of, the argument given to the throw will be returned (or 1 if there
was no argument). Note that case is not significant in the F; or in
the F<.
:F< is an errset and a catch at the same time! Amazing what happens when
your program works by simply examining a bunch of flags!
F= does an ordered comparison of strings. If "F=" has numeric args, they
specify the range of buffer to be used as the first comparison string.
Otherwise, the "=" should be followed by the name of a q-reg which
should hold the first comparison string. The second comparison string
should follow the command as a string argument, as for the "I" command.
(the @ modifier works just as it does for the "I" command) the two
strings are compared, and if they are equal 0 is returned as the value
of the "F=" command. If the first string is greater, a positive value
is returned; if the second, a negative value. If the value isn't 0,
its absolute value is 1 + the position in the string of the first
difference (1 if the first characters differ, etc.). A string is
considered to be greater than any of its initial segments.
F? mbox control; argument is bit-decoded. No arg, or arg=0, implies
arg=30 .
bit 1.1 - close gap.
May be needed for communication with other programs that don't
understand the gap.
bit 1.2 - GC string space.
Useful before dumping out, or if it is suspected many strings have
recently been discarded.
bit 1.3 - sweep the jump cache.
Necessary if a string's contents have been altered by the F^E command,
and might be a macro that might have contained "O" commands. Also
necessary if :EJ is used after increasing the value of FS :EJPAGE
(thus replacing one file with another in core).
bit 1.4 - flush unoccupied core.
Good to do every so often, or if it is likely the buffer has just
shrunk.
bit 1.5 - close the gap, if it is > 5000 characters long.
It is good to do this every so often, in case the user deletes large
amounts of text; say, whenever excess core is flushed.
FA performs text justification on a range of the buffer specified by 1 or
2 args (as for K, T, commands, etc.).
The idea is that whenever you edit a paragraph, you use FA or a macro
that uses FA to re-justify it. The line size is kept in FS ADLINE .
A CRLF followed by a CRLF, space or tab causes a break. So does a
CRLF, space or tab as the first character of the text being justified.
An invisible break can be produced before or after a line by beginning
or ending it with space-backspace. CRLFs that do not cause breaks are
turned into spaces. Excess spaces that wind up at the end of a line
are deleted. Other excess spaces are retained. Thus, to win, you
should insert spaces after all ends of sentences which are at the ends
of lines, before you call FA. You might insert spaces at the ends of
all sentences, but you can presume that they are already there, when
desired, in the middle of the line. Spaces at the beginning of a line
are treated as part of the first word of the line for justification
purposes, to prevent indentation of paragraphs from changing. The last
part-line of stuff to be justified is only filled. Tabs prevent
justification of what precedes them on a line; to prevent filling, you
must put in a break (use sp-bs). I suggest using "FA" in the following
macro:
[0 Z-^YU0
^XJ <.,Z-Q0FB.
^O?
; :0L I >
!""Make sure .'s and ?'s at end of line have spaces!
^X,Q0FA !actually justify!
]0
If you want indented paragraphs, simply indent them the right amount
when you type them in. "FA" will leave the indentation alone. "FA"
knows about backspace. Sometimes it is desirable to put a space in a
word. To do that, use space-backspace-space.
Tab characters in the buffer or in typeout are counted using tab stops
at a spacing controlled by FS Tab Width.
@FA like "FA" but only fills (doesn't justify)
FB bounded search. Takes numeric args like K, T, etc. Specifying area of
buffer to search, and a string argument like S, N, etc. The colon and
atsign flags are used as they are by other search commands. :FB is
like :S, not like :L. That is, :FB returns a value indicating extent
of success, and searches the same range of the buffer as FB with no :.
If two args in decreasing order are given searching is done in reverse.
With one negative arg, the search is forward, but through a range that
ends at the pointer.
FC takes arguments like K and converts the specified portion of the buffer
to lower-case. Only letters are converted.
@FC converts a specified portion of the buffer to upper case.
<ch>:FC returns the upper-case equivalent of the character whose numeric code
is <ch>, as a numeric code. Meta-bits in <ch> are passed through
unchanged. :FC may also be given a string pointer as argument. It
returns a new string containing the upper-case of its argument.
FD a list manipulating command whose main use is in "<arg>FDL", which
moves down <arg> levels of parens. FD returns a pair of args for the
next command. If <arg> is positive, they specify the range of the
buffer from the pointer rightward to the first character that is <arg>
levels up; if negative, leftward to the first character -<arg> levels
up.
FE inserts a list of TECO error messages and explanations in the buffer
before the pointer, one message per line.
<arg>FE inserts only the line describing the error of which <arg> is the error
code. <arg> might have been returned by an errset, or might be the
value of FS ERROR . Since error codes are actually strings, <arg>FE
is equivalent to G(<arg>) I<crlf>
@FE<errname>
returns the error code associated with the given error name <errname>.
Only the first three characters of <errname> are used. This is useful
for analysing anticipated possible errors and recovering appropriately.
Another way to do that is to compare the first three characters of the
error code, which is a string, against the expected ones, with F~.
:FE inserts a list of FS flag names in the buffer before the pointer, one
name per line.
FG does error processing. With no argument, it simply rings the termi-
nal's bell. Given the @ modifier, it also throws away type-ahead.
Given a nonzero numeric argument (which should be s string), FG prints
its contents as an error message (obeying FS VERBOSE). Accompanying
the numeric argument with the : modifier causes the error message to be
typed at the top of the screen (think of : FT). Unlike most commands
that do typeout, FG does not change Q..H, so that typing an error
message will not inhibit buffer display or ^R redisplay. Instead, FG
sets FS ERRFLG so that the next buffer display will not overwrite the
line(s) occupied by the error message.
FI input one character from the terminal and return its ASCII value.
(same as vw without the v) if the "mode" (in q-reg ..J) has changed,
the new value will be put on the screen, unless input is already
waiting when the FI is executed.
:FI similar to FI, but doesn't flush the character. It will be re-read by
the next FI or by TECO's command string reader.
@FI is like FI, but returns a character in the 9-bit TV character set,
rather than converting it to ASCII as FI does.
In the TV character set, the 400 bit means "meta", the 200 bit means
"control", and the bottom 7 bits are a printing character (if < 40, it
is one of the new TV graphics, or else it is a formatting character).
Note that there exist controlified lower case letters different from
their upper case counterpart (for example, 341 octal is control lower
case a).
@:FI analogous.
FJ insert the TECO job's command string as read from DDT in the buffer.
Will normally end with a CR-LF but may be null.
FK returns minus the value of FS INSLEN; that is, minus the length of the
last string inserted by "I", "G" or "\", or found by a search or "FW".
FK is negative except after a successful backward search, or backward
"FW". Thus, "SFOOFKC" will move to the beginning of the FOO found.
"-SFOOFKC" will move to the end of the FOO found. See also the ^B
command in this context. "SFOOFKDIBAR" will replace FOO with BAR.
See "^F". "IBLETCHFKC" inserts BLETCH and backs over it.
FL parses lists or S-expressions:
<arg>FL a list maniulating command, that returns 2 values specifying a range of
the buffer. If <arg> is >0, the range returned is that containing the
next <arg> lists to the right of the pointer; if <arg> is <0, the range
is that containing <arg> lists to the left of the pointer. This
command should be followed by a command such as K, T, X, FX ... which
can take 2 args; the specified number of lists will be deleted, typed,
put in q-reg, etc. To move to the other side of the lists, do
"<arg>FLL". The syntax parsed by FL is controlled by the delimiter
dispatch table in Q..D; the character types known are "A", " ", "|",
"/", "(", ")" and "'", and any character can be redefined to be of any
of those types.
:FL is like FL, but stops before the ( that starts the list instead of
after. -:FL stops after the ), etc.
<arg> @FL
is like "<arg>FL", but refers to <arg> s-expressions rather than <arg>
lists. An s-expression is either a list or a LISP atom, whichever is
encountered first. "@FW" is used to find LISP atoms when necessary.
@:FL stops before the next s-expression--if it is a list, it stops
before the (, and if it is quoted it stops before the quote.
FM:
<m>,<n>FM
attempts to move the pointer so that the cursor will appear at hpos
<n>, <m> lines below where it started out. "FM" without the "@"
modifier can move only toward the end of the buffer. It operates by
moving the pointer downward in the buffer until either 1) the exact
desired absolute hpos and relative vpos have been reached, in which
case "FM" simply returns, or 2) the end of the buffer is reached, which
causes a "NIB" error, or 3) the line below the desired one is reached,
in which case it is known that the desired combination of hpos and vpos
does not exist, so FM reverses its motion until it is back on the
desired line, then issues a "NHP" error. "FM" tries to avoid leaving
the cursor between a CR and the following linefeed. "FM" will not
currently work if ^R mode has never been entered, but it need not be in
^R mode. The ":" modifier causes "FM" to accept any hpos greater than
or equal to the second argument as a condition for success, rather than
demanding exact equality. The "@" modifier causes "FM" to scan toward
the beginning of the buffer rather than toward the end. The first
argument should not be positive. The algorithm is otherwise unchanged
and ":" has the same meaning (accept any hpos >= the specified one).
FN is the same as [..N :I..N. It is needed because it elminates the
possibility of a ^G-quit between the push and the insert. If such a
quit happened, the previously set up undo action would be performed
twice instead of once, and that might have bad results. To perform the
opposite action--pop and macro Q..N - just do "-FS QPUN".
The ..N macro has no effect on the value(s) returned by the macro that
set it up. The atsign flag allows the user to specify a string
delimiter, as with the I command.
FO<q><name>
binary-searches tables of fixed-length entries. It is intended for
searching and constructing symbol tables. <q> should be a q-vector or
pure string containing the table, and <name> the item to search for.
The table's data must be an integral number of words. The first word
of the table must contain the number of words per table entry; the rest
of the table is then divided into entries of that size. TECO
initialized this size to 2 words per entry, but it can be made larger.
The first word of each entry should be the entry's name, as a TECO
string pointer. This name is what FO will match against its string
argument. The second word of each entry should be the value; the use
of any extra words is up to the user. The entries' names must always
be kept in increasing order, as F~ would say, or FO's binary search
will lose. Also, they should not contain leading, trailing, or
multiple spaces, or any tabs. Their case is ignored.
FO, without colon, will return the value from the entry if the name is
found; otherwise, an UVN or AVN error results.
@FO allows only exact matches. Abbreviation is not allowed.
:FO returns the offset (in words) of the entry found; if the name is
not found, :FO returns minus the offset (in words) of the place the
name ought to be inserted in the table. The offset of the first entry
in the table is 1, to skip the word in the front that contains the
entry size.
<arg>FO is like plain FO except that if the name is undefined <arg> is
returned as its "default value". Ambiguous names still cause errors.
Here is a macro that uses FO to create variables that can then be used
with the Q<name> construction:
[0 :I0 ! Get variable name in Q0 !
! Find it, or where to put it if not found !
[1 :FO..Q 0U1
Q1"L ! If not found, put it in !
Q..Q[..O ! Symbol table lives in ..Q !
-Q1*5J 10,0I 10R ! Make space at right place !
! Install string containing variable name !
Q0,.FSWORD'
If this macro is put in QV, then MVFoo will create a variable named
Foo.
If the table is a pure string, the data must start on a word boundary,
which means that the string's header must start in the second character
in its word. In addition, the pointers to the entries' names are taken
to be relative to the table itself. That is, the "pointer" should be
an integer which, when added to the TECO string pointer to the table,
should give a TECO string pointer to the name of the entry.
FP:
<obj>FP
returns a number describing the data type of the object <obj>. The
possible values are (in DECIMAL):
-4 A number, not even in range to point into pure or impure string
space.
-3 A number that is in range for pure string space but does not
point at a valid string header.
-2 A number that is in range for impure string space but does not
point at a valid string header.
-1 A dead buffer.
0 A living buffer.
1 A Q-vector.
100 A pure string.
101 An impure string.
FQ<q> returns the number of characters in q-reg <q> (-1 is returned if the
q-register contains a number).
FR tells TECO to update the displayed mode from q-reg ..J, provided it has
changed, and no terminal input is available. :FR erases the mode line.
"FS Flags"
FS reads in a flag name as a text argument. Flag names may be any length,
but only the first six characters are significant. Spaces are totally
ignored. Only enough of the flag name to make it non-ambiguous is
required. However, in programs, abbreviation should be minimized. The
result of the FS is the current value of the flag. If an argument is
given to the FS and the flag can be set, it is then set to that value.
If a flag can be set, to make its value the second operand of an arith-
metic operator put the FS command in parens. Otherwise, FS will think
it has an arg and set the flag. Flags labeled "read-only" do not
require that precaution. Flags currently implemented are:
FS % BOTTOM specifies the size of the bottom margin as a percentage of the
number of lines being displayed. Initially 10. Rather than
let the cursor appear inside the bottom margin, TECO will
choose a new buffer window--unless the bottom of the buffer
appears on the screen already.
FS % CENTER specifies where TECO should prefer to put the cursor when
choosing a new window, as a percentage of the screen from the
top. Applies even if the end of the buffer appears on the
screen--in fact, the purpose of this variable is to make sure
that when you go to the end of the buffer some blank space is
provided to insert into without total redisplay. Initialy 40.
FS % END specifies (as a percentage of total size) the size of the area
at the bottom such that TECO should never choose a new window
putting the cursor in that area. Initially 30.
FS %OPLSP (read only) nonzero if the terminal is inferior to a LISP job
(actually, if the superior has set the %OPLSP bit in the
.OPTION variable of the TECO).
FS % TOP the size of the top margin. Analogous to FS %BOTTOM.
Initially 10.
FS %TOCID (read only) nonzero if the terminal can insert and delete
characters. This flag reflects the bit with the same name in
the terminal's TTYOPT variable, and it is updated whenever TECO
is restarted or FS TTY INIT is done.
FS %TOFCI (read only) nonzero if the terminal can generate the full 9-bit
character set. See FS %TOCID.
FS %TOHDX (read only) nonzero if the terminal is half-duplex. See FS
%TOCID.
FS %TOLID (read only) nonzero if the terminal can insert and delete
lines. See FS %TOCID.
FS %TOLWR (read only) nonzero if the terminal can generate lower case
characters. See FS %TOCID.
FS %TOMOR (read only) nonzero if the user wants --MORE-- processing, in
general. See FS %TOCID.
FS %TOOVR (read only) nonzero if the terminal is capable of overprinting.
See FS %TOCID.
FS %TOROL (read only) nonzero if the user has selected scroll mode. See
FS %TOCID.
FS %TOSAI (read only) nonzero if the terminal can print the SAIL
character set. See FS %TOCID.
FS *RSET initially 0. Nonzero suppresses automatic unwinding of TECO's
various pdls each time through the top level loop. In other
words, when FS *RSET is non-zero, errors not caught by errsets
enter break-loops in which q-regs may be examined (unless the
user's error-handler macro in q-reg ..P intervenes). The
break-loop may be returned from with ")^\", or thrown out of
with "^W" or "F;". The suspended program and its callers may
be examined with FS BACKTRACE. For more info on break-loops,
see under q-reg ..P.
FS .CLRMOD (normally -1) If < 0, TECO clears the screen whenever it gets
the terminal back from its superior. If 0, that is not done
(used mainly for debugging TECO). If > 0, screen clearing is
totally eliminated, even if requested by the program (use this
for debugging macros that try to destroy trace information).
FS .KILMOD normally -1. If 0, FS BKILL doesn't actually kill.
FS .TYI BACK backs up the pointer FS .TYI PT by one step. Back up the
pointer n steps and then you can use FS .TYI NXT n times to
get the n previous input characters.
FS .TYI NXT is used to extract from the ring buffer of saved type-in
characters. See FS .TYI PT.
FS .TYI PT is TECO's pointer into the ring buffer of the last 60 input
characters. All input characters read by TECO are saved in
this buffer, for the sake of programs to tell the user what he
typed by mistake. This pointer is used in conjunction with FS
.TYI BACK and FS .TYI NXT, for extracting the contents of the
ring buffer. This is done with the following code:
FS .TYIPT[1 [2
< FS .TYINXT U2
do something to print the character in Q2.
FS .TYIPT-Q1@;>
Each FS .TYI NXT extracts the next character from the buffer
and advances the pointer. When the pointer has been advanced
all the way around to its original position, the entire buffer
has been printed.
After an input character is read and stored in the buffer, FS
.TYI PT is initialized to point at that character. Though FS
.TYI PT is changed by ths use of FS .TYI NXT and FS .TYI
BACK, this has no effect on how input characters are stored.
FS :EJ PAGE is the number of the lowest page used by :EJ'd shared pure
files. Initially 256. If multlipied by 5*1024, and then added
to 400000000000 (octal), the result is a suitable string
pointer to the last file :EJ'd. :EJ looks at this flag to
figure out where to insert the next file to avoid clobbering
the previous ones. It is an error to set this flag explicitly
to a value lower than it already has; when it is set to a
higher value, the intervening pages are removed from the
address space.
FS :ET MODE (Twenex only) controls how filename defaults are used by the
:ET command. A bit mask of version, type, name, directory, and
device (from 1 to 20 respectively).
FS ADLINE is the line-size used by the FA command.
FS ALTCOUNT the number of 's that TECO has seen at interrupt level. That
is, an approximation to the number of command strings that the
user has typed ahead. Useful in user-defined buffer display
macros (q-reg ..B).
FS BACK ARGS (read-only) returns the arguments of a macro call level up on
the stack. It returns 0, 1, or 2 values, as F^X does. The
argument to FS BACK ARGS is either the positive number of a
frame counting from the bottom (0 = the outermost frame), or a
negative number counting back from the currently executing
macro (which, by the way, has no stack frame and cannot be
referred to in either way).
FS BACK DEPTH (read only) is the number of macro call frames on the stack.
This does not include the currently executing macro.
FS BACK PC returns the PC of a macro call frame. Which frame, is
specified as in FS BACK ARGS. The PC of a frame is the number
of the next character to be executed, relative to the beginning
of the string.
<m>,<n>FS BACK PC
sets the PC of the frame specified by <n>, to <m>.
FS BACK QP PTR (read-only) gives the level of the bottom of a macro call
frame's q-register pdl frame. This is the level which a ^\
done in that macro will unwind to. The macro call frame is
specified as for FS BACK ARG.
FS BACK RETURN (write-only) returns control to the macro call frame specified
as for FS BACK ARG. If control left that frame not with an M
but via an exit from within a TECO command (such as a ^R),
control is returned to that command. -1 FS BACK RETURN is
equivalent to ^\.
FS BACK STRING (read-only) returns a pointer to the string or buffer being
executed by macro frame specified as for FS BACK ARG.
Sometimes a macro frame will be executing a string constant
internal to TECO. There cannot be a string pointer to such an
object, so a byte pointer to the object (a number, according to
FQ) will be returned instead. All you can do with such values
is compare them.
FS BACKTRACE used to see what program is running at higher levels of the
mcro pdl. The program is inserted in the buffer, and point is
put at the place it is executing. The macro call frame is
specified just as for FS BACK ARGS.
FS B BIND is useless, but F[ B BIND and F] B BIND are useful for
pushing to a temporary buffer, or popping back from one. F[ B
BIND pushes ..O, then does FS B CREATE, but with the extra
feature that if an error happens instead of just popping back
..O, the temporary buffer will be killed. That is because
instead of doing ]..O, F] B BIND will be done, which is just
like FS B KILL with no argument.
If after creating a buffer with F[ B BIND you change your mind
and want to keep it, pop the previously selected buffer off the
pdl with the ] command. The F[ B BIND will no longer be on
the stack to kill the new buffer when you return.
An argument to F[ B BIND specifies the initial size of the
termporary buffer in characters.
<n>FS B CONS returns a newly cons'ed up buffer <n> characters long. The
contents are all initially zeros, and the pointer starts out at
the beginning of the buffer. If <n> is not specified, 0 is
assumed. When a buffer is newly created it is at the top of
memory. The closer a buffer is to the top of memory, the more
efficient it is to do large amounts of insertion in it.
FS BCREATE is like FS B CONS U..O--the buffer is selected instead of
returned.
FS BKILL see q-reg ..O. FS BKILL is used for freeing buffers
explicitly. With an argument, it frees the argument, which
should be the result of applying the q command to a q-reg
containing a buffer. Attempting to kill the currently selected
buffer is an error. For example, QAFS BKILL kills the buffer
in qa. After that is done, qa still contains a buffer pointer,
but it has been marked "dead". If there were other pointers to
the same buffer in other q-regs, TECO will regard them too as
"dead" buffer pointers. An attempt to select the buffer using
one of those pointers will result in an error. FS BKILL may
be used without an argument, in which case it pops the q-reg
pdl into Q..O, and if the new value of Q..O is different from
the old, the old value is killed.
FS BOTHCASE (initially 0) >0 => searches ignore case of letters. That is,
the case used in the search string is irrelevant, and either
lower or upper case will be found.
<0 => searches ignore case of special characters also ("@[\]^_"
= "`{|}~<rubout>").
FS BOUNDARIES reads or sets the virtual buffer boundaries (this command
returns a pair of values) the virtual boundaries determine the
portion of the buffer that most other commands are allowed to
notice. Normally the virtual boundaries contain the whole
buffer. See the B, Z and H commands, and FS V B and FS V Z.
FS BS NO LF if nonzero inhibits the LF that follows backward motion or
rubbing out, in ^R mode on printing terminals.
FS CASE like F$ (F-dollar) but neither inserts the case-shift and
case-lock if no arg, nor expects a string arg. That is, it
gets or sets the numeric quantity which determines the standard
case and whether to flag on output.
FS CCL FNAME (Twenex only) a string, in the same format as FS D FILE, of
the jfn given in AC1 if TECO was started at the CCL entry
point; or zero if it was not or the filename has already been
read. Discards the JFN unless given an atsign modifier.
FS CLK INTERVAL
is the interval between real-time clock interrupts, in 60'ths
of a second. If it is zero, real-time interrupts do not
happen. Note that real-time interrupts are not actually
processed unless/until TECO is waiting for input. Their main
use is for saving the buffer if the user walks away from the
terminal without saving it. FS IN COUNT may be useful with
real-time interupts, and FS MODIFIED. Setting FS CLK
INTERVAL postpones the next clock interrupt to one full
interval in the future.
FS CLK MACRO is the real-time interrupt handler macro. If the macro types
out, it must not leave Q..H set.
FS CTL MTA if negative suppresses the ^R-mode definitions of all control-
meta-letters (and ctl-meta-[, \, ], ^ and _) to make it easy to
insert control characters. This mode is convenient for editing
TECO commands.
FS CNG BUFFER a circular buffer of insertions/deletions made in FS TOP BUF.
A new value for this should be created whenever a user buffer
is created and FS TOP BUF should be set equal to that buffer.
Entries in FS CNG BUFFER are in pairs; the first word is an
amount of change and the second is the position of the change
(the position of an insert is the cursor position before the
insertion and the position of a deletion is the cursor
postition after the deletion). Use FS NEW CNG to update this
for recent changes before accessing it. Use Z to check it's
size. Point for it points to the next position that would be
written to. This is updated by explicit calls to FS NEW CNG
and when the gap moves.
This can be used to implement marks which are automatically
updated for insertions and deletions before them in the buffer.
To do this, record point in FS CNG BUFFER when the updating
mark is created and step through FS CNG BUFFER to its current
point, updating the mark for the changes seen along the way,
when the mark is accessed. See the MARKER library for an
example of how this is done.
This can also be used to relate a mark referenced in a disk
file to the corresponding position in a buffer which contains
an edited version of that file.
FS DATA SWITCHES
(read only) the contents of the PDP10 console switches.
FS DATE (read only) is the current date and time, as a number in
file-date format. It can be fed to FS FD CONVERT or to FS IF
CDATE.
FS D DEVICE is the current default device name, as a numeric sixbit word.
See F6.
FS DD FAST (read only) is nonzero if the current default device is a fast
device--that is, the local machine's disk.
FS D FILE is the current default filename (that ER would use) as a
string pointer. Do G(FS D FILE) to insert it in the buffer.
This flag is very useful for pushing and popping with F[ and
F]. The exact format of the string is the SNAME, a semicolon,
a space, the device name, a colon, a space, the FN1, a space,
and the FN2. To extract specific names from the string, search
for spaces (or colon or semicolon) not preceded by a ^Q. Note:
on ITS, the default device name will never be DSK:. It will be
the name of the local machine instead. This is so that
comparison of two filenames which have been passed through the
defaults and read out with FS D FILE will not say they are
unequal because one has device DSK: and the other the machine
name.
FS D FN1 is the current default first file name, as a numeric sixbit
word. See F6.
FS D FN2 is the current default second filename, as a numeric sixbit
word. See F6.
FS D FORCE is to be used to "force out" a buffer redisplay for which the
normal mechanism of deferring redisplay for input and later
resumption will not do the right thing (such as, because the
buffer being displayed is not the one permanently selected).
Setting FS D FORCE nonzero has two effects: it forces the
redisplay through to completion without considering the
presence of input, and it inhibits updating the mode line.
FS D SNAME is the current default SNAME, as a numeric sixbit word. See
F6.
FS D VERSION is the current default file version number; actually, a reflec-
tion of FS D FN2. If the default FN2 is numeric, FS D
VERSION is that fn2 as a number. If the default fn2 is ">" or
"<", FS D VERSION is respectively 0 or -2. Otherwise, FS D
VERSION is -1. Writing -1 into FS D VERSION has no effect;
writing any other value sets the default fn2 appropriately. On
Twenex, versions are always numeric, so all values have their
usual meaning.
FS D WAIT if set nonzero causes TECO to pause slightly before each line
of output. This should give better overall response on slow
displays. It will make things much worse on fast displays, and
slightly worse on printing terminals. This flag is initialized
by FS TTY INIT and at startup, according to the terminal
speed.
FS ECHO ACTIVE if nonzero says that output has been printed in the echo area
during this ^R command, so ^R should clear the echo area when
it next wants to read a command. Clearing is not done by the
FI command; only when the next distinct ^R command is to be
read. Commands which wish to type in the echo area and not
have their output erased can set this flag to zero. The FG
command does, when it types in the echo area. FS ECHO FLUSH
must be nonzero to enable this feature. Otherwise, the echo
area is never cleared gratuitously.
FS ECHO CHAR when a ^R command starts being executed, holds the character
that invoked it; set to -1 if anything is typed out; on
printing ttys, if this flag is still not -1 when the command
returns to ^R, the char is echoed. The command can set this
flag itself to control the echoing. It can set the flag to a
string, also. Then, if the command must be echoed, the whole
contents of the string will be typed.
FS ECHO DISPLAY
(write only) like FS ECHO OUT, but outputs in display mode, so
that ITS ^P-codes may be sent. See .INFO.;ITS TTY for details
on available options.
FS ECHO ERRORS if nonzero, causes error messages to be printed in the echo
area.
FS ECHO FLUSH if nonzero, enables the automatic clearing of the echo area
after each ^R command which uses it. See FS ECHO ACTIVE for
details of how to control this.
FS ECHO LINES the number of lines at the screen bottom to be used for command
echoing. Default is 1/6 of screen size, except 0 on printing
terminals. If this flag is set to -<n>, echoing is turned off,
and there are <n>-1 echo lines. Thus,
-1FS ECHOLINES makes no echo and no echo area;
-5FS ECHOLINES makes no echo but a 4 line echo area;
0FS ECHOLINES makes echo but no echo area.
Even if echoing is off, FS ECHOOUT may be used.
FS ECHO OUT (write only) is used for outputting to the echo area. If the
argument is a number, it is taken as the ASCII code for a
character to be typed. If the argument is a string, all the
characters in it are typed. Characters are output as they
would actually echo. Thus, sending a CR will actually do a
CRLF, and sending a ^A will print either downarrow (in :TCTYP
SAIL mode) or caret-A.
FS ERR same as FS ERROR if read; if written, causes an error with the
error code that is written in it. Thus, to cause a "You Lose"
error with 3-letter code LUZ, do :I*LUZ<tab>You Lose FS ERR.
Your error message should not contain any CRLFs. Users who
wish to generate errors themselves with the same codes that
TECO uses should use TECO's standard strings for those errors
(that is, do @FE IFN FS ERR) so that comparing FS ERROR
against @FE values will still work.
FS ERRFLG is used to signal the buffer display routine (whether built-in
or user-written) that an error message is on the screen and
should not be overwritten. Its value is -<n> if the first <n>
lines contain an error message, or nonnegative if there is
none. If typeout is done when FS ERRFLG is negative, TECO
will not actually type the first <n> lines of it. The <n>+1st
line of typeout will appear in its normal position, beneath the
error message. By that time, FS ERRFLG will be zero again.
FS ERROR the error code of the most recent error. Errors caught by
errsets are included. A TECO "error code" is now just a string
containing the text of the error message. Everything up to the
first tab is the "brief" part of the error message; if FS
VERBOSE is 0, that is all that TECO will print out. You can
see if an error was (for example) an "IFN" error by doing F=(FS
ERROR)IFN and seeing if the result's absolute value is 4. It
still works to compare against @FEIFN, which returns the
standard string that TECO always uses for internally-generated
IFN errors.
I.T.S. I/O errors now have messages starting with "OPNnnn"
where nnn is the I.T.S. open-failure code. Macros which used
to decode I/O errors by numeric comparison must switch to using
F=, since the strings for such errors are consed up by TECO as
needed.
FS ERR THROW (write only) return control to the innermost error-containing
command loop. This could be either an error catch command (:@<
... >), a ^R level, or the top level TECO command loop. This
command is the correct way for a user error handler (..P) to
abort the computation which got the error. The argument given
to FS ERR THROW is returned from the error catch, if it
happens to throw to an error catch. Otherwise, the argument is
discarded.
FS EXIT (write only) does a .BREAK 16, using the argument to FS EXIT
as the address field. See DDT DOC for a description of what
the arguments mean. "100000." is a good value. AC 2 will
contain the address of the 7-word "buffer block" describing the
current buffer. See the section "buffer block" at the end.
FS EXPUNGE (T(w)enex only) expunges the connected directory. FS MSNAME
can be used to connect to a directory so as to expunge it.
FS FDCONVERT converts numeric file dates to text and vice versa. If there
is a numeric arg, it is assumed to be in the format for its
file dates, and converted to a text string which is inserted in
the buffer. The form of the string is dd/mm/yy hh:mm:ss. In
this case, no numeric value is returned. If there is no arg, a
text string is read from the buffer starting at ., and . is
moved over the string. The string should be in the format
inserted by FS FDCONV with argument, and will be converted to
a numeric file date which will be the value of FS FDCONV. See
FS IFCDATE and FS OFCDATE. <n>:FS FD CONV returns a string
containing the printed representation of the file date <n>,
instead of inserting it in the buffer. Twenex uses ODTIM and
IDTIM, and so is less picky about date formats it will accept.
Also, a second argument to FS FSCONV is used as the ODTIM
format flags.
FS FILE PAD the character used to pad the last word of files written by
TECO. Normally 3 (for ^C).
FS FLUSHED is nonzero if a --MORE-- has been flushed, and type-out is
therefore suppressed. The flag is positive if the flushage was
due to a rubout, negative otherwise. You can stop generating
type-out when FS FLUSHED is nonzero, or you can clear it to
make type-out start actually appearing again.
FS FNAM SYNTAX controls TECO's filename readed. If 0, when only one filename
is present, it is used as the fn2 (this is the default). If
positive, a lone filename is used as the fn1. If negative, a
lone filename is used as the fn1 and automatically defaults the
fn2 to ">". The default TECO init file uses this flag to
process a DDT command line.
FS FORK JCL (Twenex only) gives a command line (jcl) for the inferior fork
invoked via the next FZ command.
FS GAP LENGTH (read only) the length of the gap. This is the value of EXTRAC
(see "buffer block").
FS GAP LOCATION
(read only) the buffer position of the gap. This is GPT-BEG
(see "buffer block").
FS HEIGHT (read only) number of lines on the screen, on display terminals
(including --MORE-- and command lines). On printing terminals,
wil be a very large number.
FS HELP CHAR contains the character to be used as the HELP character.
Normally, it contains the code for C-_. However, you may want
to bind it to -1 from time to time to prevent HELP from being
recognized (such as, in the C-Q command).
FS HELP MAC is a macro to be executed if the HELP character is typed. HELP
is Top-H on TV's, ^_H on any terminal. If FS HELP MAC is
zero, the HELP character is ignored as a ^R command, and
returned (as 4110 octal) by FI and VW.
FS H POSITION (read-only) returns the number of character positions there
would be to the left of the type ball if the contents of the
buffer (or at least everything after the previous carret) were
printed on a hardcopy terminal with backspaces really backing
up and tab stops every FS Tab Width columns.
FS HSNAME is the user's home directory. The home directory is a little
more permanent than the working directory (FS MSNAME) and is
used for storing things that permanently belong to the user,
such as the RMAIL file, which do not have their own special
directories the way init files do.
FS I&D CHR if nonzero, tells TECO to try to use the insert and delete
character operations to speed redisplay. Initialized nonzero
if the terminal handles those operations. Don't set it nonzero
otherwise!
FS I&D LINE if nonzero, tells TECO to try to use the insert and delete line
operations to speed redisplay. Initialized nonzero if the
terminal handles those operations. Don't set it nonzero
otherwise!
FS IBASE the input radix for numbers not followed by "." (initially
8+2)
FS I.BASE the input radix for numbers ended by ".". Initially 8.
FS IF ACCESS (write-only) sets the access pointer of the current input file
--the argument is the desired character address in the file.
FS IF CDATE the creation date of the currently open input file. Arg and
value are in numeric file date form - see FS FD CONVERT.
FS IF DEVICE (read-only) is the device name of the current or most recent
input file, as a numeric SIXBIT word.
FS IF DUMP (ITS only) is the dumped-bit of the currently open input file.
FS IF FDB (Twenex only) is used for reading and writing the file
descriptor block of the current input file. <n>FS IF FDB
returns word <n>, and <m>,<n>FS IF FDB sets it to <m>.
FS I FILE (read-only) is the name of the current or most recent input
file, as a string. The format is like that of FS D FILE.
FS IF FN1 (read-only) is the first file name of the current or most
recent input file, as a numeric SIXBIT word.
FS IF FN2 (read-only) is the second file name of the current or most
recent input file, as a numeric SIXBIT word.
FS IF LENGTH (read-only) the length, in characters, of the currently open
input file; or -1, if that length is unknown (because the file
is on a device for which the fillen system call is
unimplemented). Error if no file is open.
FS IF LINKP (read-only) -1 if the currently open input file was reached by
tracing a link; zero otherwise. Always zero on Twenex. On old
versions of ITS it is also always zero.
FS IF MTAPE (write-only) executes a .MTAPE call on the input file. The
last argument is the .MTAPE operation. A preceding argument
specifies the count (default is 1). It is not clear that this
feature really works.
FS IF REAP is the don't-reap bit of the currently open input file.
FS IF SNAME (read-only) is the SNAME of the current or most recent input
file, as a numeric SIXBIT word.
FS IF VERSION (read-only) is the version number of the open input file, or -1
if there is none or its FN2 isn't numeric.
FS IMAGE OUT outputs arg as to the terminal as a character in superimage
mode. Returns no value. If the argument is a string pointer,
the contents of the string are output.
FS IN COUNT is an old name for FS TYI COUNT.
FS INSLEN length of last string inserted into the buffer with an "I", "G"
or "\", or found with a search command or "FW". FS INSLEN
will be negative after a backward search or "FW" with negative
arg. See "FK" and "^F".
FS INVMOD if nonzero, causes the mode line to be displayed in inverse
video on terminals which support it.
FS JNAME (read only) returns the JNAME of the job TECO is running in, as
a numeric SIXBIT word, which can be converted into text by the
F6 command. Note that the XJNAME is also available, and might
be better for your purpose--see FS XJNAME.
FS JRN EXECUTE (write only) opens a journal file for execution (replaying).
The default filenames are used. With a colon modifier, the
journal file being replayed is closed. See the section on
journal files for more information.
FS JRN IN (read only) is nonzero when a journal file is being replayed.
FS JRN INHIBIT if nonzero causes input to be taken from the terminal even
though a journal file is being replayed. This is how FS JRN
MACRO can offer the user a recursive ^R to fix things up after
a quit.
FS JRN INTERVAL
The value of this flag controls how often the journal file
being written is updated on disk. It is in the form of a
number of commands. It is initially 50.
FS JRN MACRO This macro is called whenever TECO attempts to read a command
from a journal file being replayed and finds a colon or a ^G
character in the file. The colon or ^G is passed to the macro
as a numeric argument. In the case of ^G, this macro should
execute a ^R, and then quit by setting FS QUIT to -1. In the
case of a colon, the macro should read more characters from the
file using FS JRN READ and act on them. The format of these
characters is not specified.
FS JRN OPEN (write only) opens a journal file for writing. The default
filenames are used. With a colon modifier, the output journal
file is closed. See the section on journal files for more
information.
FS JRN OUT (read only) is nonzero when a journal file is being written.
FS JRN READ (read only) reads a character from the input journal file being
replayed. If there is none, it returns a random value.
FS JRN WRITE (write only) outputs its argument, a character or string, to
the journal file being written. It does nothing if no journal
file is being written.
FS LAST PAGE (read only) set to -1 when an input file is opened; set to 0 as
soon as the last char of the file is read in. Saved by E[ -
E]. Updated by FS IF ACCESS. Thus, FS LAST PAGE; will exit
an iteration if there is no more to be read.
FS LEDEFS (initially 0) specifies the correspondence between definitions
of ^R command characters and the function codes of the local
editing protocol. Its value should be a qvector containing
pairs of elements: alternating definitions and function codes.
The definitions are macros or built-in functions, the same as
would go in FS ^R CMAC. The function codes are documented in
the local editing protocol.
FS LEDEFS can also have a string value. In this case, when
the value is wanted, the string is executed as a macro. It
should set FS LEDEFS to a qvector as described above.
If FS LEDEFS is zero, the local editing protocol is not used.
FS LINES (initially 0) determines the number of lines displayed by
standard buffer display, and, for display terminals, the number
of lines to use at all. 0 => a full screen on displays, 2
lines on printing terminals. <n> not zero => <n> lines.
FS LISPT normally 0, this flag is set nonzero if TECO is started at 2 +
its normal starting address. This is intended to indicate to
TECO programs that passing of text between TECO and its
superior is desired.
FS LISTEN returns nonzero if there is input available to be read by "FI".
If given an arg, then if no input is available, the arg is
typed out using FS ECHOOUT.
FS LOAD AV (Twenex only) returns the system load average.
FS MACHINE (read only) returns the name of the machine TECO is running on,
as a numeric SIXBIT word, which can be turned into text with
F6. On ARPANET Twenices, this returns the local hosts hostname
as a string.
FS MODE CHANGE
if nonzero means that FS MODE MACRO needs to be run eventual-
ly, to update the contents of ..J. Whenever TECO is consider-
ing updating the mode line, depending on the value of this flag
it may run FS MODE MACRO first. That macro can recompute ..J
to display the current state of things. FS MODE CHANGE is set
to zero before FS MODE MACRO is called.
The precise condition is: if FS MODE CHANGE is positive, do
run FS MODE MACRO. If FS MODE CHANGE is negative, its
absolute value is compared with twice the value of FS QP PTR;
if the latter is less, do run FS MODE MACRO. Thus, if FS MODE
MACRO sets FS MODE CHANGE based on the current value of FS QP
PTR, it can arranged to be called again if control returns to
an outer level on the stack. See Q..J and FR.
FS MODE MACRO if nonzero is the macro used to update Q..J when the mode line
is about to be displayed. See FS MODE CHANGE and Q..J and FR.
FS MODIFIED is the current buffer's modified flag. This flag is set
nonzero whenever the buffer's contents are changed. It can be
read or written by the user at any time. Each buffer has its
own flag, but only the selected buffer's flag is accessible.
The intended use is for deciding whether a file must be written
back to the disk. When this flag is nonzero, a star appears at
the end of the mode line. See also FS READ ONLY and FS X
MODIFIED and FS ^R STAR.
FS MP DISPLAY (write only, ITS only) outputs text to the main program area in
display mode (^P is special). The argument may be a single
character or a pointer to a string, whose entire contents are
output.
FS MSNAME is the user's working directory name (set up from the SNAME
that TECO was given when it started up), as a numeric SIXBIT
word, which can be converted into text by the F6 command. On
Tenex or Tops-20, this is the connected directory and writing
into it is used to connect to another directory.
FS NEW CNG (write only) used to force an update to FS CNG BUFFER when
that buffer needs to be accessed.
FS NOCEOL if nonzero, signifies that the terminal in use does not have
the clear-to-end-of-line function. Programs may wish to clear
the screen at times if this flag is set, if they know that
clearing the screen would result in faster redisplay afterward
on such terminals.
FS NOOP ALTMODE
if negative, altmode is always a noop as a command. If 0,
altmode is an error as a command. If >0, always ends execution
(as ^_ does). Initially -1. The old treatment of altmodes was
as if this flag were set to 1.
FS NOQUIT gives the user control of TECO's ^G-quit mechanism. See "^G".
FS OF ACCESS (write-only) sets the access pointer in the output file. The
argument must be a multiple of 5. If the last output done did
not end on a word boundary, rather than throwing away the
remaining characters, an error occurs. FS OF LENGTH gives the
length of the file, if you want to append to the end.
FS OF CDATE the creation date of the currently open output file, in numeric
file-date form.
FS O FILE returns the filenames of the last output file explicitly
closed, as a string. The format is like that of FS D FILE.
The intended use is for finding out what version number was
actually written.
FS OF LENGTH returns the length in characters of the currently open output
file, or -1 if it cannot be determined.
FS OF MTAPE (write-only) does a .MTAPE call on the output file. The last
argument is the .MTAPE operation. A preceding argument
specifies the count (default is 1). It is not clear that this
feature really works.
FS OF VERSION (read-only) is the version number of the last output file
closed, or -1 if that file's FN2 was not numeric.
FS OLD FLUSHED Saves the value of FS FLUSHED when that is set to zero, on
returning to ^R. Thus, a ^R command can check FS OLD FLUSHED
to see whether the previous command had output which was
flushed.
FS OLD MODE is the last ..J value actually displayed in the mode line.
Setting this flag to zero will force redisplay of the mode
line.
FS OLD Z is the value of Z the last time FS NEW CNG was called.
FS OSPEED The terminal's output line speed in baud, or 0 if the speed is
not known.
FS OS TECO returns the operating system TECO is running on, 0 for ITS, 1
for 20X, 2 for 10X.
FS OUTPUT if nonzero, suppresses output to the EW'd file. Output
commands (P, etc) are errors.
FS PAD CHAR (T(w)enex only) is the character to use for padding terminal
output. Normally it is a Rubout (177). For some terminals a
null (0) is better. Some may set it to 0 automatically. -1
means use an actual delay instead of padding characters. This
may make some terminals work better, and may be more efficient
of CPU time; however, it will not work across networks of any
sort.
FS PAGENUM the number of formfeeds read (with non-atsign Y and A commands)
from the input file since it was opened.
FS PJATY this is negative if TECO has detected that the terminal was
temporarily taken away from it. A negative value here will
cause the whole screen to be refreshed at the next opportunity.
FS PROMPT the ASCII value of the prompt character (initially 38 for "&").
TECO will prompt on printing terminals only, whenever it is
about to read from the terminal, and FS PROMPT is not 0.
FS PUSHPT (write-only) pushes its argument on the "ring buffer of the
pointer", but only if the argument differs from the value
already at the top of the ring buffer. See the ^V command.
Note that TECO's top level loop does Q..IFS PUSHPT each time
it is about to read in a command string.
FS QP HOME:
<n>FS QP HOME returns a string which says where the q-register pdl slot <n>
was pushed from. <n> can be a nonnegative offset from the
bottom of the stack or a negetive offset from the top. The
string will contain the name of the q-register of FS flag that
was pushed, as, for example, "QA", "Q.^RX", "QFoo", "FS
DFILE", or "*" (for a [(...) ). "*" isn't really a q-register
name, but what would be any better?
<n>:FS QP HOME returns the address of the q-register which q-register pdl slot
<n> was pushed from (for a variable, returns the name of the
variable). Such numbers will be equal for two slots pushed
from the same place in the same TECO. They are also used with
F^G.
<n>@FS QP HOME turns a q-register address returned by :FS QP HOME into a
string such as plain FS QP HOME would return. @FS QP HOME
may be useful in for decoding the local q-register home numbers
used with the F^G command.
FS QP PTR the q-register pdl pointer (0 if nothing has been pushed, 1 if
one q-reg has been pushed, etc.) <n> FS QP PTR sets the
pointer to <n> if <n> > 0; adds <n> to it if <n> is negative.
It is illegal to increase the pointer value with this command.
FS QP SLOT <n> FS QP SLOT reads q-reg-pdl slot <n>. <m>,<n>FS QPSLOT
sets it to <m>. The first slot is numbered 0. If <n> is
negative, it is treated as FS QPPTR+<n>. Thus, -1FS QP SLOT
is the last slot pushed.
FS QP UNWIND (write only!) like FS QP PTR but pops slots back into the
q-reg's they were pushed from instead of simply decrementing
the pdl poinetr. This unwinding is automatically done when an
error is caught by an errset, and at the end of each command
string, and by ^\ and FS ^REXIT. If Q..N is popped by this
command, it is macroed first (see ..N). If <n> is negative,
<n>FS QP UNWIND pops -<n> slots.
FS QUIT ^G-quit works by setting this flag negative. Whenever quitting
is possible (see FS NOQUIT) and FS QUIT is negative, quitting
will occur (and FS QUIT will be zeroed automatically). When
TECO's quitting is inhibited, the user can test this flag
explicitly to do his own special quitting.
<n>FS Q VECTOR (a pseudoflag) returns a newly cons'ed up q-register vector,
<n> characters long. <n> should normally be a multiple of 5.
The contents are initialized to zeros, and the pointer is at
the beginning of the qvector. A q-vector is really a buffer,
each word of which is marked by the garbage collector. See the
section on data types.
FS RANDOM reads or sets the ^Z command random number generator's seed.
FS READ ONLY if nonzero makes it an error to modify the buffer. This flag
is actually per-buffer, so when you set it, you set it only for
the currently selected buffer.
FS REAL ADDRESS
returns the value of BEG, the character address of the
beginning of the current buffer. Useful for communicating with
other programs that need to be given addresses of data in their
commands. Also useful for executing the buffer as PDP10 code
(do FS REALAD/5U0 M0; the code should be position-independent,
expect its address in accumulator 5, and start with SKIP (skip
never) instruction. Its argument will be in AC 3.).
FS REFRESH if nonzero, is macroed each time TECO really clears the whole
screen. It is given no args and its values are ignored. The
screen will already have been cleared.
When only part of the screen is in use (because FS LINES and
FS TOP LINE call for that), the only time that TECO will clear
the whole screen is when it is continued after having been
stopped, the primary use of this hook is to put back on the
screen whatever is supposed to be in the part of the screen not
being actively used for display.
Functions which remove part of the screen from active use can
sometimes be entered recursively, each one removing a few more
lines from use. Each of them might supply an FS REFRESH to
refresh those lines. What ought to happen is that all the FS
REFRESHes are executed, in the order they were set up. To
make this happen, any function which sets up an FS REFRESH
should save the previous contents elsewhere, and the new FS
REFRESH should call the old one first thing.
FS REREAD (usually -1) if nonnegative, FS REREAD is the 9-bit TV code
for a character to be re-read. Putting 65 into FS REREAD will
cause the next "FI" command to return 65 (and set FS REREAD
back to -1).
FS RGETTY 0 if printing console, otherwise equal to the tctyp word of the
terminal. However, it is better to decode the FS %TOCID,
etc., flags than to decode FS RGETTY when trying to determine
what kind of display the terminal is, and what functions it can
perform. On Twenex it is actually allowed to set this variable
in case the system is mistaken about your terminal type. What
it must be set to is the TECO internal type code for the
terminal you are using; and not all types are assembled in on
any particular Twenex site.
FS RUB CRLF if nonzero causes the initial definitions of ^D, rubout and
control-rubout to delete both characters of a CRLF at one blow,
as if it were a single character.
FS RUB MACRO if nonzero is a macro to be called to perform the ^R commands
Rubout and C-D when they have explicit numeric arguments. The
normal definitions of the two characters call this macro in
that case.
FS RUNTIME (read-only) TECO's runtime in milliseconds.
FS SAIL if nonzero, the terminal is assumed to be able to print non-
formatting control chars as 1-space graphics. TECO outputs
them as they are instead of outputting an ^ and a non-ctl char.
Terminal initialization zeros this flag if the terminal's TOSA1
bit is 0 (this bit is set by :TCTYP SAIL).
FS S ERROR if 0, as it is initally, a failing serach within an iteration
or a ^P-sort key is not an error--it simply fails to move the
pointer. If not 0, such searches cause sfl errors like all
other searches.
FS SHOW MODE if nonzero, causes FR to type out the mode line (Q..J) on
printing terminals, if it has changed since last printed. Has
no effect on displays.
FS S HPOS (read only) is the horizontal position of point, taking control
characters, tabs, CRs, etc. to appear the way they are current-
ly being displayed, but assuming an infinitely wide line.
FS S STRING is the default search string (which S will use), as a string
pointer. Do G(F S STRING) to insert it in the buffer. This
flag is most useful for pushing and popping.
FS STEP MACRO (normally 0) if nonzero and numeric, TECO displays the buffer
and waits at the beginning of every line of the program. See
^M for details. If it is a string, it is executed at the
beginning of every line in the program. Exception: if a macro
begins with a "W", stepping is inhibited at the beginning of
that macro. The macro can inhibit stepping throughout itself
by starting with "W 0F[STEP MAC". Exception: stepping is
also done whenever a successful conditional begins.
FS STEP DEPTH restricts the macro call stack levels at which stepping is
done. If FS STEP DEPTH is -1, as it is initially, stepping
goes on at all stack levels. Otherwise, the value of FS STEP
DEPTH is the largest macro call depth (FS BACK DEPTH value)
for which stepping can take place.
FS SUPERIOR if nonzero is the macro to be called when TECO's superior makes
a request to insert text into TECO. See "How Superiors Can Put
Text into TECO" below.
FS S VALUE the value stored by the last search command (0 if search
failed; else negative, and minus the number of the search
alternative which was actually found).
FS TAB WIDTH (initially 8) is the spacing between tab stops for display of
tab characters in the buffer. Although the system always uses
8-character tab stops, TECO handles output of tabs itself and
can output with any interval between tab stops.
FS TOP BUFFER is a duplicate copy to the top level EMACS buffer (the one
selected with Select Buffer). Compare ..O against this to see
if the current buffer is top level.
FS TOP LINE is, on display terminals, the number of the first line on the
screen that TECO should use. Normally 0, so TECO starts output
at the top of the screen.
FS TRACE nonzero iff TECO is in trace mode. See "?". 1F[ TRACE is a
good way to start tracing temporarily.
FS TRUNCATE says what to do with long lines of type-out. Negative =>
truncate them. Positive or zero => continue them to the next
line. Entering ^R sets this flag to 0.
FS TTMODE (initially 0) non-zero tells TECO that normal buffer display
should display on printing terminals. (if there is a user
buffer display macro, this flag has no effect unless the macro
checks it)
FS TTY FCI (Twenex only) if positive, we assume that the terminal has an
Edit key, and that the 200 bit in incoming characters should be
interpreted as "Meta". If this flag is zero, then the 200 bit
is ignored on the assumption that it is a parity bit. If this
flag is negative, the terminal has full 12-bit character input.
This only works under VTS.
FS TTY INIT (no argument or value) causes TECO to reexamine the system's
terminal description and reset various flags, and the cursor in
..A, appropriately. Then, FS TTY MACRO is executed if
nonzero. It can be used to digest the tty characteristics and
set flags accordingly. FS TTY INIT is run automatically when
TECO is started or restarted.
In detail, ..A is set to "-!-" on printing terminals, and to
"/\" on displays (but "^A^B" on imlacs). FS RGETTY is set up
to be 0 on a printing terminal, nonzero otherwise. FS VERBOSE
is set equal to FS RGETTY. FS TTYOPT is read in from the
system. FS ^H PRINT is zeroed unless the terminal can
backspace and overprint; FS ^M PRINT is zeroed unless the
terminal can overprint. FS SAIL is set nonzero if the %TOSA1
bit is set in TTYOPT (this is the bit ":TCTYP SAIL" sets). FS
LID is set nonzero if the %TOLID bit is set in TTYOPT. %TOLID
says that the terminal can insert and delete lines. FS WIDTH
and FS HEIGHT are read in from the system. FS ECHOLINES is
set to 0 on printing terminals; 1/6 of the screen size on
displays. FS D WAIT is set to -1 if FS OSPEED is positive
and 600 or less; to zero, otherwise.
FS TTY MACRO is a macro called by FS TTY INIT to give the user a chance to
alter TECO flag settings based on the newly-gobbled terminal
characteristics. If you don't like the way TECO initializes
certain FS flags (namely FS ECHOLINES, FS TRUNCATE, FS
VERBOSE, FS WIDTH, FS ^HPRINT, FS ^MPRINT, and FS SAIL) in
FS TTY INIT, this macro can change them. Pure strings should
NOT be used for this; when a saved EMACS environment is
restored, FS TTY MACRO$ is processed before even the standard
libraries are loaded in. So you must create the string with
:I, X or :G. You can make an impure copy of a pure string in
Q0 with :I0 0.
FS TTYOPT (read-only) the TTYOPT word for the terminal. However, if you
think you want to use this flag, see FS %TOCID, etc., first.
FS TTY PAGE MODE
(Twenex only) if negative, prevents TECO from leaving page
mode, so that ^Q and ^S are still used for flow-control. Note
that this means they are not available as commands.
FS TTYSMT (read-only) the TTYSMT word for the terminal.
FS TYI BEG is the value which FS TYI COUNT had on the last time through
the main ^R command loop. In other words, it is the number of
terminal input characters so far, not including the last or
current ^R command. Commands to set the numeric argument do
not count as real commands in this regard; they are grouped
with the commands for which they set the argument. When ^R is
reading the first character of a command, FS TYI COUNT has
been incremented already, so it equals FS TYI BEG+1.
FS TYI COUNT is the number of characters read from the terminal so far.
FS TYI SINK if nonzero holds a macro to be called every time a character is
read from the terminal (not from FS REREAD or from FS TYI
SOURCE). The character read, in the 9-bit code, is passed as
a numeric argument to the macro. The macro should return a
single value, for the sake of ^R display updating. FS TYI
COUNT and FS TYI BEG may be of use in the macro.
FS TYI SOURCE if nonzero holds a macro to be called to obtain "terminal
input". This is instead of reading from the keyboard. The
macro should put the input character it wishes to provide into
FS REREAD and then return. The macro should return a single
value, for the sake of ^R display updating, but this value is
not used in any other way. That FS TYI SOURCE is nonzero is
taken to imply that input is available, so display updating is
suppressed. To cause displaying to be done, you must bind FS
TYI SOURCE to zero and then request it. FS TYI SOURCE is set
to zero by anything that discards keyboard input (errors,
quits, etc).
FS TYO HASH <vpos>FS TYO HASH returns the hash code of the screen line at
position <vpos>. <n>,<vpos>FS TYO HASH sets the hash code of
that screen line to <n>. This is useful primarily for
-1,<vpos>FS TYO HASH which will force that screen line to be
redisplayed.
FS TYO HPOS (read-only) while typeout is in progress (FS TYPEOUT nonnega-
tive), holds the current typeout horizontal position, in which
the next typed character will appear.
FS TYO VPOS (read only) while typeout is in progress (FS TYPEOUT nonnega-
tive), holds the current typeout vertical position, in which
the next typed character will appear.
FS TYPEOUT is -1 if typeout has not been happening recently, so typeout
starting now would appear at the top of the window. FS
TYPEOUT is not -1 when typeout was the last thing to happen
and any more typeout will appear after the previous typeout.
:FT types at the top of the window by putting -1 in FS TYPEOUT
before typing.
FS U HSNAME is used to determine a user's hsname. <user> FS U HSNAME
(where <user> is sixbit) returns <user>'s hsname in sixbit.
<its>,<user> FS U HSNAME returns his hsname on machine <its>
(sixbit).
FS UINDEX (read only) The user index of the TECO job.
FS U MAIL FILE is used to determine the filename (including the machine) of a
user's mail file. <user>FS U MAIL sets the default filename
to the name of <user>'s mail file (where <user> is in sixbit).
<its>,<user>FS U MAIL sets them to the name of his mail file
on machine <its> instead of his normal mail-receiving machine.
FS UNAME (read only) returns the UNAME of the job TECO is running in, as
a numeric SIXBIT word, which can be converted into text by the
F6 command. See also FS XUNAME and FS MSNAME, one of which
might be better for your purpose.
FS UPTIME (read only) returns time system has been up, in 30'ths,
(milliseconds on Twenex).
FS UREAD (read-only) -1 iff an input file is open, else 0. Once an
input file is opened, it remains open until "EC", "@Y", "@A",
"EE" or "EX" is done.
FS UWRITE (read-only) -1 if an output file is open, else 0.
FS VAR MACRO if nonzero enables the feature whereby setting a named variable
can run an arbitrary macro to make changes in other data
structures. These data structures will appear automatically to
reflect the value of the variable.
To use this feature, allocate three words per variable in the
symbol table in Q..Q. The macro to call is the contents of the
third word, but only if it is a string which starts with a "!".
If that is the case, it will be called with the new value of
the variable as its argument.
FS V B is the distance between the real beginning of the buffer and
the virtual beginning. See FS BOUNDARIES, but unlike that
flag, FS V B can be pushed and popped. B has the same value
as FS V B.
FS VERBOSE if not 0, TECO will print the long error message of its own
accord when an error occurs. Otherwise it will print only the
3-char code and the long message must be requested by typing
^X. Initially 0 except on displays.
FS VERSION (read-only) the current TECO version number
FS V Z is the distance between the virtual end of the buffer and the
real end--the number of characters past the virtual end. See
FS BOUNDARIES for more info, but note that FS V Z can be
pushed and popped. Z's value is FS Z-(FS V Z).
FS WIDTH width of terminal's screen or paper, in characters.
FS WINDOW the number of the first character in the current display
window, relative to the virtual beginning of the buffer (that
is, FS WINDOW+B is the number of that charcter).
FS WINDOW+BJ (FS HEIGHT-(FS ECHOLINES)/2)L will put the
pointer in the middle of the window (usually). Setting FS
WINDOW will make TECO try to use the window specified.
However, if the constraints of FS %TOP and FS %BOTTOM are not
met, TECO will choose another window rather than use the
specified one.
FS WORD gets or sets words in the current buffer. This flag makes it
possible for TECO programs to edit binary data bases. <n>FS
WORD returns the contents of the word containing character
<n>; <val>,<n>FS WORD sets that same word. When handling
binary data, it is unwise to insert or delete characters other
than in units of five, on word boundaries. The way to delete a
word is to delete its five characters; insert a word with 5,0I
(this does not set the low bit! You cannot count on the word
to contain 0 unless you store into it with FS WORD).
To read in a file of binary data, FY should be used, since Y
might pay special attention to the characters in the file.
Copying out of another buffer with G works, provided the
transfer starts and ends on word boundaries (blt is used). For
writing out binary data, use @HP. The @ says not to clear the
low bits. Use HP rather than PW PW since PW may add a ^L. EF
is OK for closing the file--it will add no padding if it is
done at a word boundary.
FS XJNAME (read only) returns the XJNAME of the job TECO is running in,
as a numeric SIXBIT word, which can be converted into text by
the F6 command. The XJNAME is "what the JNAME was supposed to
be", so if you want your init file to do different things
according to how TECO was invoked, you should use the XJNAME
rather than the JNAME. On Tops-20, this will be the first atom
of the command line, if there is one; this is useful for the
same reason.
FS X MODIFIED is completely analogous to FS MODIFIED in how TECO treats it.
However, the user can clear either one without changing the
other. They can be used to detect the occurrence of
modifications since two different types of events (such as,
real saves and auto saves). FS X MODIFIED does not affect the
star in the mode line; only FS MODIFIED does.
FS X PROMPT On printing terminals, all commands that type out first print
and zero FS X PROMPT if nonzero (using FS ECHO OUT). Do not
try to use it on displays.
FS XUNAME (read only) returns the XUNAME of the job TECO is running in,
as a numeric SIXBIT word, which can be converted into text by
the F6 command. The XUNAME is "who the user really is". For
example, it is what TECO and other programs use to decide whose
init file to use.
FS Y DISABLE controls treatment of Y command.
0 => Y is legal.
1 => Y is illegal (gives "DCD" error).
-1 => Y is always treated as @Y.
FS Z (read only) the number of characters in the buffer. Will
differ from value of Z command when virtual buffer boundaries
don't include the whole buffer. This is Z-BEG (see "buffer
block").
Note: In the names of the following flags, "^" represents caret, not a control
character. Control characters cannot be part of FS flag names.
FS ^H PRINT controls how ^H is typed out. Negative => actually backspace
(and overprint), otherwise type the ^H as caret-H. FS TTYINIT
and G cause this flag to be zeroed if the terminal cannot
handle overprinting.
FS ^I DISABLE controls the treatment of the tab character as a TECO command.
0 => ^I is an insert command (see Tab for details).
1 => ^I is illegal (gives "DCD" error).
-1 => ^I is a no-op.
FS ^L INSERT (initially 0) if 0, formfeeds in files that terminate Y
commands' reading are thrown away, and the P and PW commands
output a formfeed after the buffer. If FS ^LINSERT is
nonzero, formfeeds read from files always go in the buffer, and
P and PW never output anything except what is in the buffer.
Either way, a Y and a P will write out what it reads in.
FS ^M PRINT says when a stray CR or LF should be typed out as one, as
opposed to being printed as "^M" or "^J". Possible values and
initialization like FS ^H PRINT
FS ^P CASE if nonzero, ^P sort ignores case (lowercase letters sort like
the corresponding uppercase).
FS ^R ARG is the explicit numeric argument for the next ^R mode command,
or 0 (not 1!) if there was none.
FS ^R ARGP contains two bits describing this ^R-command's argument:
bit 1.1 (1) is set if any argument was specified (either
numerically or with ^U).
bit 1.2 (2) is set if a numeric argument was specified. If
this bit is 0, the contents of FS ^R ARG are ignored,
and 1 is used instead.
bit 1.3 (4) is set if the argument, as specified by the other
bits, should finally be negated.
FS ^R CCOL the comment column, for ^R's comment mode.
FS ^R CMACRO <n>FS ^RCMAC gets the ^R-mode definition of the character
whose ASCII code is <n>. <m>,<n>FS ^RCMAC sets it to <m>.
<n> should be an ASCII code; it will be converted to 9-bit TV
code which is what is actually used to index the ^R-mode
dispatch table. If you wish to supply a 9-bit code yourself,
use "@FS ^RCMAC" which skips the conversion. Also, these
definitions may now be referred to as q-regs in all the q-reg
commands--see "Q". The definition is either a built-in command
or a user macro. In the former case, the definition is a
positive number of internal significance only. However,
built-in definitions may be copied from one character to
another using FS ^RCMAC. For a character to be a user macro,
its definition must be one of the funny negative numbers which
are really string pointers. They can be obtained from strings
by applying the "Q" command to a q-reg that contains text. For
example, to make the definition of the character " " be the
string which is at the moment in q-reg A, do "QA,^^ FS
^RCMACW". "QAU^R " is equivalent. To copy the definition of
"A" into the definition of rubout, do "^^AFS ^RCMAC,127FS
^RCMACW". This will make rubout self inserting (unless "A"
had been redefined previously).
FS ^R DISPLAY if nonzero is macroed every time ^R is about to do nontrivial
redisplay (anything except just moving the cursor). If the
evaluation alters the needed redisplay (either by returning 0
or 2 values to ^R, or by doing some of the redisplay with ^V)
then ^R will take note. If a FS ^R DISPLAY returns no values,
it will force a full redisplay, thus effectively disabling ^R's
short-cuts, so beware. If FS REFRESH is nonzero, then it will
be called in addition to FS ^R DISPLAY, at those times when
the whole screen is being cleared.
FS ^R EXIT (write-only) exits from the innermost ^R invocation. Pops
q-regs pushed within that ^R level, and ends iterations started
within it.
FS ^R ECHO 1 => characters read in by ^R should not be echoed.
0 (the default) => they should be echoed only on printing
terminals.
-1 => they should be echoed on all terminals.
Note that this "echoing" is explicit typeout by TECO. System
echoing is always off in ^R mode, currently. Also, rubout is
not echoed on printing terminals. However, FS ^R RUBOUT on a
printing terminal when FS ^R ECHO is <= 0, types out the char
being deleted.
FS ^R EC SD is used to allow system echoing to echo the Space character
when some sort of auto-fill feature is in use and Space does
not have the definition of a normal self-inserting character.
This flag should be set to the definition which Space has when
it does auto-filling. When Space has this definition, it will
be considered safe to let the system echo Spaces just as if
they were ordinary self-inserting characters; however, to
prevent auto-fill from being lost, system echoing will be
allowed only as far as the column which is the value of FS
ADLINE, which should be set no greater than the column at
which auto-fill starts to do something nontrivial. The
definition of Space will not actually be executed when the
space is echoed by the system, but for an auto-fill which isn't
going to break the line this should make no difference.
FS ^R ENTER is macroed (if nonzero) whenever ^R is entered at any level of
recursion.
FS ^R EXPT is the ^U-count for the next ^R-mode command.
FS ^R H MIN (read only) is the hpos of the first change on the screen
needing redisplay. It will be a large positive number if no
redisplay is required. If FS WINDOW is negative then the
value of this flag doesn't matter.
FS ^R HPOS the current horizontal position of the cursor in ^R mode. Not
updated when the pointer moves, unless ^R gets control back or
@V is done.
FS ^R INDIRECT given a 9-bit character, traces ^R alias-definitions to find
the character it is equivalent to. If given a character that
isn't an alias, returns the same one. Thus, 311. FS ^R IND
returns 11.
FS ^R INHIBIT when nonzero prevents ^R from updating the display. If FS ^R
INHIBIT is zeroed again, all the pending updating will be done
at the next opportunity.
FS ^R INIT <ch>FS ^R INIT returns the initial definition of the character
whose ASCII code is <ch>; in other words, <ch>FS ^R INIT
always returns what <ch>FS ^R CMACRO initially returns. The
atsign modifier works for FS ^R INIT just as it does for FS ^R
CMACRO; it says that the arg is a 9-bit code rather than
ASCII.
FS ^R INSERT the internal ^R-mode insert routine's user interface. It takes
one argument--the ASCII code for the character to be inserted.
This command itself take care of notifying ^R of the change
that is made, so when returning to ^R this change should not be
mentioned in the returned values (so if this is the only change
made, return 1 value). This command is very sensitive; if the
buffer or even "." has changed since the last time ^R was in
progress or an @V was done, it may not work. Its intended use
is in macros which, after thinking, decide that they wish only
to insert 1 or 2 characters (such as a space-macro which might
continue the line but usually inserts a space).
FS ^R LAST holds the most recent character read by any ^R invocation
(quite likely the one being processed right now). Commands
that wish to set up arguments for following commands should
zero FS ^R LAST, which tells ^R not to flush the argument when
the command is finished.
FS ^R LEAVE is macroed (if not zero) whenever ^R returns normally
(including FS ^R EXIT but not throws that go out past the ^R).
FS ^R MARK holds the mark set by ^T in ^R mode, or -1 if there is no mark.
FS ^R MAX holds the maximum number of characters of insertion or deletion
that will be printed out by ^R on a printing terminal. Larger
changes will cause ^R to echo the command instead of displaying
its effect. The default value is 50 .
FS ^R MCNT the counter used by ^R to decide when to call the secretary
macro. It starts at FS ^R MDLY and counts down.
FS ^R MDLY sets the number of characters that should be read by ^R mode
before it invokes the secretary macro kept in q-register ..F .
Characters read by user macros called from ^R are not counted.
FS ^R MODE (read-only) non-zero while in ^R-mode.
FS ^R MORE if positive, --MORE-- is used for ^R-mode display instead of
the usual --TOP--, --BOT-- and --nn%--. This is useful in
command environments where Space means "show the next
screenfull". If negative, then neither --MORE-- nor --TOP-- is
displayed. This may be desirable on slow terminals, and also
allows ..J to make use of the full width of the mode line.
FS ^R NORMAL all "self-inserting" characters in ^R mode are really initially
defined to go indirect through this word, if it is nonzero. If
it is zero, as it is initially, the default definition is used
for such characters.
FS ^R PAREN holds a function to be executed whenever a self-inserting
character is inserted whose Lisp syntax is ")". The idea is
that this function will point out the location of the matching
open parenthesis. If FS ^R PAREN is zero, the feature is
turned off.
FS ^R PREVIOUS holds the previous (second most recent) command read by ^R's
command loop, not counting argument setting commands.
FS ^R REPLACE if nonzero puts ^R in "replace mode", in which normal
characters replace a character instead of simply inserting
themselves. Thus, the character A would do DIA instead of
just IA. There are exceptions, though; a ^H, ^J, ^L or ^M
will not be deleted, and a tab will be deleted only if it is
taking up just one space. Also, characters with the meta bit
set will still insert. Replace mode actually affects only the
default definition of "normal" characters. Characters which
have been redefined are not affected, and if FS ^R NORMAL is
nonzero no characters are affected (unless the user's
definitions check this flag). Making FS ^R REPLACE positive
has the additional effect of forcing all meta-non-control
characters to be come normal, suppressing their definitions.
FS ^R RUBOUT the internal ^R rubout routine's user interface. Takes 1 arg--
the number of characters to rub out. This command is very
sensitive and may fail to work if the buffer or "." has been
changed since the last time ^R was in control, or an @V, FM, FS
^R RUB or FS ^R INSERT was done. Its intended use is for
macros which, after thinking, decide to do nothing but rub out
one character and return; it gives extra efficiency but only
when rubbing out at the end of the line.
FS ^R SCAN if nonzero causes ^R commands, when using a printing terminal,
to try to imitate a printing terminal line editor by printing
the characters they insert/delete/move over. FS ^R ECHO
should be 1, to avoid double-echo. See also FS ^R TTM1 for
how to customize this.
FS ^R STAR if nonzero, a star appears in the mode line if the buffer is
modified. It is nonzero by default.
FS ^R SUPPRESS (initially -1) nonnegative => builtin ^R-mode commands are
suppressed, except for rubout, and user-defined commands are
suppressed unless their definitions begin with "W". Suppressed
command characters become self-inserting. The char whose 9-bit
value is in FS ^R SUPPRESS is the unquoting char. It
reenables suppressed commands temporarily by setting FS ^R
UNSUPPR to -1. If FS ^RSUPPRESS is > 511, there is no
unquote char.
FS ^R THROW returns control to the innermost invocation of ^R. This is
different from FS ^R EXIT, which returns control FROM that
invocation.
FS ^R TTM1 if nonzero, will be called to handle display on printing
terminals of operations TECO itself does not know how to
display. This includes operations that return no values to ^R,
operations which only move the cursor but move it a long way,
and operations which modify a region of the buffer which is
longer than FS ^R MAX or does not end at point.
When an operation returns no values to ^R, FS ^R TTM1 is
called with no arguments.
When an operation moves the cursor a long distance, FS ^R TTM1
is passed one argument, which is the old cursor position.
When an operation modifies a region which ^R itself does not
know how to display for, FS ^R TTM1 receives two arguments,
which delimit the region changed. These two argumemnts will
not necessarily be in order.
If FS ^R TTM1 does not output anything, then the command is
echoed by ^R when FS ^R TTM1 returns.
If FS ^R SCAN is zero, redisplay is not attempted on printing
terminals and this macro is not called.
FS ^R UNSUPP (initially 0) actually, builtin commands are suppressed only if
this flag and FS ^RSUPRESS are nonnegative. However, this
flag is zeroed after each command except ^U and ^V. Thus,
setting this flag to -1 allows one builtin comand.
FS ^R V MIN (read only) is the vpos of the first change on the screen
needing redisplay. It will be a large positive number if no
redisplay is required. If FS WINDOW is negative then the
value of this flag doesn't matter.
FS ^R VPOS the ^R-mode cursor's vertical position.
FS _ DISABLE controls treatment of the "_" command. If 0 (the default), "_"
is "search-and-yank" as it originally was. If 1, "_" is
illegal (gives "disabled command" error). If -1, "_" is
treated like "-" (good on memowrecks).
FT types its string argument.
:FT similar, but always goes to top of screen first (actually, to the line
specified by FS TOP LINE).
@FT similar to FT, but types its argument in the echo area rather than the
display area. Characters are typed normally, in ITS ASCII mode, rather
than as they would echo, so to do a CRLF you need a CR and a LF.
@:FT like @FT, but types the argument only if no input is available (FS
LISTEN would return 0). If input is available, the argument is
skipped over and ignored.
FU a list manipulating command whose main use is in <arg>FUL, which moves
up <arg> levels of parentheses. <arg>FU where <arg> is positive
returns a pair of args for the next command, specifying the range of
the buffer from . Moving rightward to the first place <arg> levels up.
If <arg> is negative, it moves left -<arg> levels up.
FV displays its string argument.
:FV types its string argument, then clears whatever is left of the screen.
FW similar to FL but hacks words instead. A word is defined as a sequence
of non-delimiters. Initially, the non-delimiters are just the squoze
characters but the user can change that--see q-reg ..D. This command
returns a pair of args for the next one. Also, FW sets FS INSLEN
equal to the length of the last word moved over. Main uses: FWL moves
right one word, -FWL moves left one, FWK deletes one word to the right,
FWFXA deletes and puts in q-reg A, FWFC converts one word to lower
case.
:FW similar to FW but stops before crossing the word instead of after.
Thus, :1FWL moves up to before the next non-delimiter. :2FWL is the
same as 2FWL-FWL. :FW sets FS INSLEN to the length of the last
inter-word gap crossed.
@FW like FW, but finds LISP atoms rather than words. Understands slashes
and vertical bars but not comments.
FX like X and K combined. "3FXA" = "3XA 3K". The atsign flag causes
appending to the q-reg, as for X.
FY insert all that remains of the current open input file before point.
Error if no file is open. The input data are unaltered; no attempt is
made to remove padding or ^L's. If the transfer is on a word boundary
in the file and in the buffer, word operations will be used, so this
command is suitable for use with binary data. The input file is not
closed--use EC for that.
<n>FY like FY, but inserts at most <n> characters, or until EOF, whichever
comes first. Note that <n> characters of space are always needed, even
if the file is not really that long; thus, 1000000FY to read in the
whole file will not work. The input file is not closed.
FZ (T(w)enex only) manipulates inferior forks. This command does not work
on Tenex but could probably be made to work.
FZ resumes the inferior exec fork, creating it if there is none. There is
at most one "exec fork" since FZ will not create one if one already
exists.
0FZ<string>
resumes the inferior exec fork, creating it if there is none. The
"string" is placed in the Rescan buffer for use by the exec.
-1,0FZ<string>$
creates and starts a new exec fork placing the "string" in the Rescan
buffer. This new exec fork replaces any existing one to become "the"
exec fork, which following FZ's with no argument will resume. There
are no defaults for the filename.
FZ<filespec> <string>
creates and starts a non-exec fork by loading the specified file (no
defaults!). The "string" is placed in the Rescan buffer in the same
manner EXEC uses. Ie. "FILENAME string". The FS FORK JCL flag can
also be used to set the command line, it is just the "string" part.
After the fork returns, the FZ command returns a positive number which
is the TECO index of the fork. This index can be used to resume or
kill the fork:
<i>FZ<string>
resumes the fork of index <i>, and waits for it to return. The string
is placed in the Rescan buffer. A pre-comma argument may be given:
-1 -- signifies that the Rescan buffer is to be preset to read.
0 -- start the fork at its primary entry location.
n -- start the fork at location n in the entry vector.
-<i>FZ kills the fork of index <i>. Indices are always positive.
@FZ... is like FZ but does not clear the screen on return.
F[<flag>
pushes the value of FS<flag> on the q-reg pdl, so that it will be
restored on unwinding.
<arg>F[<flag>
pushes the flag and sets it to <arg>
<ch>F[ ^R CMACRO
pushes the definition of character number <ch>.
<arg>,<ch>F[ ^R CMACRO
pushes the definition of character number <ch> and sets it.
F_ this command has the same meaning that _ normally has; namely, search
for a string arg and keep yanking till end of file. However, this
command works regardless of the setting of FS _DISABLE
F]<flag>
pops from the q-reg pdl into FS <flag>.
<ch>F] ^R CMACRO
pops from the q-reg pdl into the definition of character number <ch>,
and returns the old definition.
F~ compares strings, ignoring case difference. It is just like F= except
that both strings are converted to upper case as they are compared.
G<q> insert in buffer to left of pointer the text in q-reg <q>. If q-reg
specified contains # rather than text, decimal representation thereof
will be inserted. If the q-reg contains a buffer the gap in the buffer
may have to be moved before the G can be done. FS INSLEN is set to
the length of the inserted text.
<m>,<n>G<q>
insert only a part of the text in the q-reg; specifically, the range
from <m> to <n>-1 inclusive. This feature works only for q-regs
containing text; if a q-reg holds a number the whole q-reg will be
inserted despite the args.
:G<q> returns a copy of the string in q-register <q>.
<n>:G<q>
returns as a number the character at position <n> in the string in <q>.
It is an error if <n> is negative or >= the length of the string.
<m>,<n>:G<q>
makes a substring of the string in <q>, taking the characters starting
form position <m> and stopping before character <n>. This substring is
returned as a value. FS INSLEN is set to the length of the substring.
H equivalent to B,Z; i.e., specifies whole buffer (or all within the
virtual boundaries if they're in use) to commands taking two args for
character positions such as K, T, or V.
I if no arg, insert following string arg (terminated by Altmode) into the
buffer before point. The characters are inserted at the pointer, and
the pointer is left after the characters.
If preceded by an atsign ("@"), then the following char is the
delimiter, and the next un-quoted and un-delimiter-protected occurrence
of that character is what ends the string argument. e.g., @I/text/.
The length of the inserted string is kept in FS INSLEN (see the "FK"
and "^F" commands).
:I<q> takes a q-register name immediately after the I and inserts into that
q-reg, replacing the previous contents. Atsign works as with the
normal I command, with the delimiter following the q-reg name. FS
INSLEN is not set by :I. Self-inserting chars will not take the colon
modifier.
<n>I inserts the character with ASCII code <n>.
<n>:I<q>
puts the character in a string in q-reg <q>.
<m>,<n>I
inserts <m> copies of the character with ASCII code <n>.
<m>,<n>:I<q>
puts <m> copies of the character in a string in q-reg <q>.
J position pointer after argth char in buffer. If no arg, arg=B (usually
0).
:J is to J as :S is to S.
K if no arg or one arg, kill chars from pointer to argth line feed
following. (no arg, arg=1; negative arg, back up over 1-arg line
feeds, space over last line feed found, and kill from there to pointer.
A colon after the arg will move back over carriage return+linefeed
before deleting. If no carriage return exists, TECO will only move
back one character. There is an implicit line-feed at the end of the
buffer. (note: this is the action of colon for all commands which take
one or two args like K.)
<m>,<n>K
kills characters <m> through <n>-1. The pointer is moved to <m>.
<n>@K is like <n>K, but only LF's preceded by CR's are recognized.
L:
<arg>L move to beginning of <arg>th line after pointer (0L is beginning of
current line.). Colon acts as in the K command. Note that :L moves to
end of current line 0:L moves to end of previous line and -:L moves to
end of line before previous line
<m>,<n>L is the same as <m>+<n>-.J
<arg>@L is like <arg> L but only CRLFs are recognized, not stray LF's.
M<q> calls the function in q-reg <q>. If <q> contains a string or buffer,
its contents are "macroed"--that is, treated as TECO commands. If <q>
contains a number, that number should be the initial definition of some
^R-mode character; that "built-in" function will be called.
Built-in functions take 1 arg; user macros, 0, 1 or 2, which they may
access using "^X" and "^Y" (or, more winningly, with the F^X and F^Y
commands). The macro may read string arguments using the ^]^X
construction; such arguments should be supplied after the M command.
Note that if you macro a buffer, you may screw yourself if while that
buffer is executing you either modify its contents or throw away all
pointers to it. If the q-register specified in the M command is a
^R-mode character definition (as in M.^RX), the code for that character
is put in Q..0 in case the definition looks at it there.
@M is a variant of M that fools the called macro into thinking that it was
called directly from ^R mode. One effect is that the default postcomma
numeric argument is 1, not 0. To be precise, if a macro is called with
@M and no arguments, then inside that macro F^X will still say that
there are no arguments, but if ^Y is used anyway its value will be 0,
not 1.
Another effect is that if the called macro uses the F^K command to read
a string argument, the argument will be read from the terminal. If a
macro called with @M does a :M, the @ flag will be passed along to the
macro called by the :M; however, this will not affect the argument
passed by the :M, which will be determined solely by the code in the
caller (including whether the caller explicitly says @).
:M is a tail-recursive form of macro call; it is similar to a M followed
by a ^\, for some purposes. However, with :M the caller is really no
longer present on the macro call stack. If the called macro reads a
string argument, it will come not out of the caller, but out of the
caller's caller.
N does search (see S) but if end of buffer is reached does P and
continues search.
O<tag> sends command execution to char after the occurrence of <tag> as a
label ("!<tag>!") ( OX goes to !X!). Case is not significant in
tags, so OFOO and Ofoo will both find both !FOO! and !foo!. Label
must be on same iteration level as O command, i.e., no unmatched
< or > between O and !. The label must also be within the same macro
as the O; in other words, non-local gotos are not implemented.
If the tag is not found, an "UGT" error occurs at the end of the O
command. For convenience's sake, :O is just like O but simply returns
if the tag is not found.
The @ modifier allows the tag to be abbreviated. OFOO will not find
!FOOBAR!, but @OFOO will find it. This is for the sake of those using
O to do command dispatching.
TECO has a cache containing the locations of several recent O commands
and where they jumped to. If an O command is in that table, searching
is unnecessary. This increases efficiency. However, if there is a ^]
call in the arg to O, it might be intended to jump to different places
each time, so TECO refuses to cache such jumps to force itself to
search each time. Also, jumps in buffers and in top level command
strings cnnot be cached, since the data in the buffer (including the
argument of the O command) might change at any time; if TECO then did
not read the argument and search, it might jump to the wrong place.
P output contents of buffer to open output file, followed by form feed
(^L) if FS ^LINSERT is 0; clear buffer and read into buffer from file
open for reading until next form feed or end of file. A single
argument means do this that many times.
The P command usually writes zero into the low bit of each word of the
output file. If the @ flag is set, then outputting on word boundaries
in the buffer and the output file outputs the low bits as they are
present in the buffer.
<m>,<n>P
output the characters in the range <m> through <n> to the output file.
Do not change the buffer or read from the input file.
PW outputs like P but does not clear buffer or do input. Takes arg,
meaning do it arg times.
Q<q> returns the value in q-reg <q>, as a number. If <q> is holding a
number, that number is the value. If <q> "holds text", then it really
contains a pointer to a string or buffer, and Q<q> wil return the
pointer, which if put in another q-reg (using "U") that q-reg will
"hold the same text" as <q>.
A q-reg name is either an alphanumeric char preceded by 0, 1 or 2
periods, a "variable name" of the form <name>, a subscripting
expression such as :Q(<idx>), a * (for certain commands), an expression
in parentheses (for certain commands), or up to 3 periods followed by a
"^R" or "^^" and any ASCII character.
Periods plus alphanumeric character q-reg names refer to TECO's
q-registers, which are what serve as variables for TECO programs. Each
distinct such name names a distinct variable. Names with two periods
are reserved for special system meanings; those that are now assigned
are documented starting at "..A".
While names like "A" or ".8" are fine for local variables in programs,
for global parameters mnemonic names are necessary. Variables with
long names are accessible through the <name> construct. Variable
names may be abbreviated, and extra spaces and tabs may go at the
beginning, the end, or next to any space or tab. Also, case is not
significant inside variable names. Thus, a variable named "Foo" could
be accessed with QFOO, Q foo or (if there is no FO or FOX, etc.)
with Q Fo. Because of this latitude, variables are not created if
they are referenced and do not exist; instead, they must be entered
explicitly in the symbol table by the user. This is easy to do,
because the entire symbol table data structure is user-accessible; it
is an FO-style symbol table that lives in q-register ..Q. See the FO
command for a sample macro for creating variables. The symbol table
must have at least two words per entry, but it may have more. The
additional words can be used however you like. The FS VARMAC feature
allows the third word to be used to hold a macro to be run when the
value of the variable is changed, but this is enabled only if FS VAR
MACRO is set nonzero. See its definition.
The elements of a q-vector may be accessed as q-registers in their own
right. If q-reg A contains a q-vector, then the "q-register" :A(0) is
the first element of it, and :A(1) is the second, etc. Indexing starts
at zero for the first element of the q-vector, but only those elements
within the virtual boundaries of the q-vector may be accessed. See FS
QVECTOR for how to create q-vectors.
A star ("*") may be used only with commands like ] and X that wish only
to store in a q-register; it causes such commands to return their data
as a value instead. Thus, :I*FOO returns a string containing FOO.
Expressions in parentheses can be used only with commands that wish
only to examine the contents of a q-register; the value of the expres-
sion is used as the contents to be examined. Commands that allow this
option include F^A, F^E, F=, FQ, F~, G and M. Thus, G(Q0) is
equivalent to plain G0.
Q-reg names containing ^R or ^^ refer to the definitions of ^R-mode
command characters. When "^R" is used, the ^R-mode definition of the
specified ASCII character is referred to; when "^^" is used, the ^R
mode definition of the specified charcter xor'ed with 100 (octal) is
meant. The periods specify the control and meta bits since ^R-mode
definitions belong to 9-bit characters but only 7-bit characters can be
inside TECO command strings; one period sets the control bit; 2, the
meta bit; 3, both control and meta. If the char is obtained from a
^]^V, then all 9 bits may be obtained from that source; the periods xor
into the number in the q-reg. For example, "Q^RA" refers to the
definition of "A", and "Q.^RA" refers to that of control-A, as does
"Q^R^]^VX" when QX holds 301 (octal). "Q^R^A" refers to the definition
of downarrow, one of the new TV printing characters, as does "Q^^A".
"Q^^J" refers to the definition of linefeed, whereas "Q.^RJ" refers to
the definition of control-J, which can be typed in only on a TV (and
which is usually defined to execute the definition of linefeed).
R move pointer left arg chars (no arg, same as arg=1).
:R is to R as :S is to S; as :C is to C.
<m>,<n>R
does "<m>+<n>-.J". This is for FLR to work.
S search. Takes following text string and looks for it in the buffer,
starting from the pointer. (if the string arg is null, the last
nonnull arg to any search command is used) if it finds it, it positions
the pointer after the string. If it does not find it, it does not move
the pointer but generates an error message unless the search is inside
an iteration (see <. See also FS S ERROR which may be used to disable
this "feature"). If the search is inside an iteration, the value as if
produced by :s (read on) will be saved whether or not the colon is
used, for use by the ; command. The effect of iterations on searches
is cancelled by errsets, so what matters is whether the search is more
closely contained in an iteration or in an errset.
A positive arg to the search means do it arg times, i.e., find the
argth appearance of the string; a negative arg means search the buffer
backwards from the pointer and position the pointer to the left of the
string if successful. If the S is preceded by "@", the char after the
S is used to delimit the text string instead of altmode. In this case,
a null arg causes a search for the null string, instead of a search for
the last string searched for. (This for the sake of macro-writers
using ^].) If the S is preceded by :, val=-1 if the search is
successful and val=0 if not--there is no error condition. Note also
the FB, N and _ commands, and the ^B command.
There are some special characters which, when used inside search
strings, do not have their normal meanings unless quoted with a ^Q:
^X matches any character.
^B matches any delimiter char (normally this means it matches any
non-squoze char, but see q-reg ..D).
^S<ch> matches any character whose Lisp syntax is <ch>. The Lisp
syntax of a character is stored in q-reg ..D.
^N matches any char other than the char that follows it in the
search string. ^N^B matches non-delimiters, and ^N^X matches
nothing. ^N^Q^B matches all but ^B. ^N^S( matches anything whose
Lisp syntax is not "(".
^O divides the string into substrings searched for simultaneously.
Any one of these strings, if found, satisfies the search. Thus,
SFOO^OBAR looks for FOO or BAR. If ^O is used inside a :S,
finding the <n>th substring makes the search return -<n> as its
value.
^Q quotes the following char, i.e., deprives it of special
significance.
In addition, ^] is special as usual.
Note that SFOO^O will always succeed, and will move point forward over
the next three characters if and only if they are FOO. -2-(:SFOO^O)
will do that and also return nonzero only if they were FOO.
T type: takes one or two args like K and types out the selected chars.
@T types in the echo area.
U:
<n>U<q> puts the number <n> in q register <q>. Returns no value.
<m>,<n>U<q>
puts <n> in <q>, and returns <m>. Thus "<m>,<n> U<q1> U<q2>" does
"<n>U<q1> <m>U<q2>".
V takes arg like K and displays chars, representing the cursor by "/\"
(or whatever is in ..A). When, after being proceded from a --MORE--, a
new screenfull is started, the place it began is remembered in FS
WINDOW so that an attempt to display the buffer will try to start at
the same place. This may make redisplay unnecessary if you search for
something that appears on the screen. Nothing is typed on printing
terminals.
@V performs standard buffer display. That is, "@V" always does what
automatic buffer display does as a default (when ..B holds 0). When in
^R mode, @V does a ^R-style display. Note that @V will display on any
type of terminal, although TECO does not normally display automatically
on printing terminals. In ^R mode, @V treats its arguments as ^R does
(as hints on how to redisplay). When not inside a ^R, @V ignores its
arguments.
If V is followed by W it becomes
VW which does V, then waits for terminal input of one char whose 7-bit
ASCII value is returned as val.
W flushes current value except when part of VW or PW.
X takes one or two args like K and enters selected chars as text into
q-register named by next char in command string. Can be retrieved by G
command and ^] substitution, q.v.
@X acts like X but appends text to q-reg rather than replacing q-reg
contents. If q-reg does not already contain text this works like
ordinary X. See also :I.
Y kills the buffer, then inserts one page from the current input file
(until first formfeed or eof). Point is left at the beginning of the
buffer. If reading is terminated by a ^L, the ^L will go in the buffer
iff FS ^LINSERT is nonzero. (FS ^LINSERT is initially 0.)
The input file is not closed, even if eof is reached. To close the
input file, use EC. However, EE does close the input file. Closing
the input file is not necessary but will lighten the drain on system
resources.
Trailing ^C's or ^@'s just before eof are considered padding and are
flushed. To do input without having any padding characters removed,
use FY.
The virtual buffer boundaries are understood. If no file is open, the
buffer is left empty. Because Y is an easy command to be screwed by,
and isn't really necessary since the A command exists, there is a way
to disable it. See FS YDISABLE.
@Y yanks in all the rest of the file. ^L's within the file go in the
buffer. A ^L at the end of the file will go in the buffer iff FS
^LINSERT is nonzero. Trailing ^C's and ^@'s are considered padding,
and flushed. The input file is closed automatically.
Z val=number of chars in buffer (more generally, the character number of
the virtual end of the buffer, if virtual buffer boundaries are in
use). See also FS Z, the actual length of the buffer, and FS BOUND
and FS VZ, which set the virtual bounds.
[<q> push text or number in q-reg <q> onto the q-register pdl. There is
only one q-reg pdl, not one per q-reg. At various times (for example,
the ^\ and F; commands, and after errors) TECO unwinds the q-reg pdl to
a previous level by popping everything back to where it was pushed
from.
The [ command does not allow subscript expressions (such as "[:A(5)")
because automatic unwinding would have no way to know how to pop the
pushed value back where it came from. If you wish to push the value
and don't mind that errors, etc. won't pop it back, do "[(Q:A(5))" or
something similar.
<new>[<q>
is equivalent to [<q> <new>U<q>.
\ Converts digits in the buffer to a number, or vice versa. If no arg,
value is the number represented as decimal digits to right of pointer
in buffer (actually, the input radix comes from FS IBASE, as with
numbers in commands). :\ allows an optional minus sign. Moves pointer
to right of number.
<n>\ inserts printed representation of <n> in buffer to right of pointer;
usually the number is "printed" in decimal, but the radix is controlled
by q-reg ..E. If two args, first specifies field size such that if 2nd
is shorter than that many chars leading blanks will be added. Sets FS
INSLEN to the number of characters inserted. See "FK" and "^F".
<m>,<n>\
is like <n>\ but pads with leading spaces to <m> columns.
<n>:\ returns a string containing the printed representation of <n>, in the
radix in ..E. Sets FS INSLEN.
<m>,<n>:\
makes a <m> character string, with leading spaces.
]<q> pop from q-register pdl into q-reg <q>. See the [ command.
^ This command has been replaced by the @ command but still works. See
the @ command.
_ if FS _ DISABLE is 0, then _ is like S, except at end of buffer do Y
command and continue search until end of file on input or until text
string found.
If FS _ DISABLE is 1, "_" is illegal. If FS _DISABLE is -1, "_" is
the same as "-".
Use "F_" in a macro to be sure of doing the search.
Rubout deletes last char typed in, and types deleted char. Done during
type-in, not during command execution. If executed (rather hard to
do), same as _. Rubouts are typed out by TECO as ^? (rubout is ctl-?)
Lower case letters are interpreted like upper case letters when they
are commands. Inside insert and search strings they are treated as
themselves.
Various special topics of interest are treated below
When TECO is started for the first time, it initializes various data areas,
prints its version number, and initializes several flags associated with the
terminal (by executing FS TTY INIT). On T(w)enex, if TECO was started at 1 +
the normal starting address, it expects to be passed a JCL and saves the JFN's
filenames, as a string, in FS CCL FNAME. If TECO was started at 2 + the
normal starting address, FS LISPT is set nonzero. Otherwise, it is set to 0.
In either case, TECO looks for a "TECO INIT" file (see below), executing it as
a program if it is found.
When TECO is restarted, it does not clobber the buffer, q-regs or open files.
It does, however, execute FS TTY INIT which resets some flags whose preferred
setting depend on the type of terminal. FS TTY INIT calls the user-supplied
FS TTY MACRO, if not 0. Then, it quits to top level and executes whatever is
in q-reg ..L (unless it is 0).
Init files:
Whenever TECO is started for the first time, it checks for a file
<hsname>;<xuname> TECO, for a file <hsname>;* TECO, and then for the file
.TECO.;* TECO. (On T(w)enex, it looks for <conn-dir>TECO.INIT and then for
EMACS:TECO.INIT). The first one found is executed as TECO commands. The last
of those files is the default init file. The other two would be personal init
files. The personal init file can do whatever you want. The only thing the
default init file does is interpret command lines from DDT as follows:
":TECO FOO BAR <cr>"
typed at DDT causes
"ET FOO BAR EI ER Y"
to be done by TECO--that is, TECO starts editing FOO BAR.
":TECO FOO <cr>"
edits FOO >.
Because COM:.TECO. (INIT) sets FS FNAMSY temporarily.
":TECO <filename><TECO commands> <cr>"
typed at DDT executes
" ET <file> <commands> ".
A user's own init file should interpreted the JCL by reading it in with the
"FJ" command. It may have any command format it wishes.
Dumped TECO programs runnable as separate programs often have their own init
files. Such packages should use FS XUNAME and FS HSNAME to determine init
file names the same way TECO does.
Journal Files:
TECO can write a journal file describing all the commands typed by the user.
If the system crashes, the user can replay the journal file later so that his
work is not lost.
The TECO program starts writing a journal file by doing FS JRN OPEN. This
opens the file for output, using the default filenames. TECO automatically
writes into the file representations of all command characters read from the
terminal. To close the journal file, use :FS JRN OPEN. To see whether a
journal file is being written, look at the value of FS JRN OUT (it is -1 in
that case). Note that no output is ever written in a journal file while
another journal file is being replayed.
The TECO program requests the replaying of a journal file by doing FS JRN
EXECUTE. This opens the file using the default filenames. When TECO is ready
to read more commands, they will be read from the journal file until the file
is exhausted, or the user types a ^G on the terminal, or the TECO program does
:FS JRN EXECUTE to close the file. FS JRN IN is -1 when a journal file is
being replayed.
Each command character is represented by a pair of characters in the journal
file. This is so that the Control and Meta bits can be represented in full
generality. A character with neither the Control nor the Meta bit is
represented in the journal file by a space followed by the character itself. A
Control character (200+nnn) is represented by an "^" followed by the
non-control character. A Meta character (400+nnn) is represented by "+"
followed by the non-meta character. A Control-Meta character is represented by
"*" followed by the basic character. Thus, Meta-F is represented by "+F".
There are a few exceptions to the rule above. A CR character (015) is
represented by the two characters CRLF. This makes the journal file look much
nicer. The Help character is represented by "??".
Other constructs which can appear in a journal file are ^G (007) to represent a
quit command; comments, which start with semicolon and end with CRLF, and are
ignored when replaying the file; and program commands, which start with a colon
and whose format is up to the TECO program. When a ^G or a colon is seen in a
journal file being replayed, the FS JRN MACRO is called, and given the
character (^G or colon) as an argument. In the case of ^G, the macro should do
1F[JRN INHIBIT and then call ^R so that the user can fix up for any timing
errors that occurred in quitting, and when the ^R returns it should do -1FS
QUIT to replay the quit. Colon represents the start of program-specific
information; the program which wrote the journal file and the one which replays
it must agree on what format the following information takes. The information
can be read using the FS JRN READ command.
One specific colon-sequence is defined by TECO: colon followed by a ^G
indicates a quit which happened synchronously, while TECO was waiting for
input. Such a quit does not need a recursive ^R for the user to fix things up
because everything is guaranteed correct. In this case, the FS JRN MACRO
should just replay the quit with -1FS QUIT.
Normally, journal files are written and read automatically. However, the TECO
program may wish to add extra information to the journal file. This could be
comments designed to aid humans who look at the journal file, or it could be
information intended to be used in replaying the file properly. In that case,
it should take the form of a colon followed by information to be read in by FS
JRN MACRO later. In either case, the information is written by means of the
FS JRN WRITE command, which accepts a character or a string.
TECO's Data Structures (Strings, Buffers and Qvectors)
TECO has two different data structures for storing sequences of characters:
strings, and buffers. They differ in what operations are allowed on them, and
how efficient they are.
Strings have less overhead than buffers, but as a penalty they are not easily
altered. Once a string has been created, its contents usually do not change;
instead one might eventually discard the string and create a new one with
updated contents. The sole exception is F^E, which makes it possible to alter
characters in a string (but not to insert or delete). Commands which "put text
in a q-register" all do so by consing up a string and putting a pointer to it
in the q-register.
Buffers are designed to be convenient for insertion and deletion. Each buffer
has its own pointer, and its own virtual buffer boundaries, which are always
associated with it. The contents of a buffer can be accessed just like the
contents of a string (in which case only the part between the virtual
boundaries is visible), but it can also be "selected" and then accessed or
altered in many other ways: insertion, deletion, searching, etc. Each buffer
also has a flag which is set nonzero whenever the buffer's contents are
changed; it can also be set by the user with FS MODIFIED. A buffer has about
42 characters of overhead, and the number of buffers is limited (about 40).
Initially, there is only one buffer in a TECO (pointers to which are initially
found in q-registers ..O and ..Z), and new ones are only made when explicitly
asked for with F[ B BIND, FS B CONS or FS B CREATE.
Strings and buffers are normally represented in TECO by pointers. When a
q-register "contains" a string, it actually contains a pointer to the string
(see the sections on internal format for details). If q-register A contains a
string, QA returns the pointer, which can be stored into q-register B; then QB
and QA both point to the same string. The command :I*<string> returns a
pointer to a newly consed up string containing <string>. :G can be used to
extract a substring (which is copied, not shared). The commands :\, :F6 and X*
are also useful for creating strings.
A buffer is selected by putting a copy of a pointer to it into q-register ..O.
TECO has a garbage collector, so that if all pointers to a buffer or string are
eliminated, the storage it occupies will eventually be reclaimed. Most of the
space occupied by a buffer can be reclaimed explicitly with the FS B KILL
command; the buffer is becomes "dead", and even though pointers to it may still
exist, any attempt to use them to select the buffer or examine its contents
will be an error.
Vectors of objects can also be represented in TECO, with either buffers or
qvectors. Buffers can be used to as vectors of numbers, while qvectors are
used as vectors of arbitrary objects (numbers, or pointers to strings, buffers
or qvectors). The difference is due to the fact that the garbage collector
knows that the objects in a qvector might be pointers and therefore must be
marked, while the objects in a buffer cannot be pointers and are ignored. The
words in a buffer or q-vector can be accessed easily with subscripted
q-register names; if QA contains a q-vector, then Q:A(0) is its first element.
To access the elements in hairier ways, you can select the buffer or q-vector
and the insert or delete, etc. Q-vectors are created by means of FS Q VECTOR.
The buffer block, and what buffers contain (and the gap):
The current buffer is described by the 7-word "buffer block" which contains
these variables:
BEG char addr of start of buffer,
BEGV char addr of lower buffer boundary,
PT char addr of pointer,
GPT char addr of start of gap,
ZV char addr of upper buffer boundary,
Z char addr of top of buffer,
EXTRAC # chars in gap.
(next come 2 words used by the communication
protocol. See below).
MODIFF nonzero if buffer has been modified.
RDONLY value of FS READ ONLY for this buffer.
Note that all character addresses normally used in TECO have BEG subtracted
from them; "B" returns BEGV-BEG; "Z", ZV-BEG; "FS Z", Z-BEG; ".", PT-BEG; "FS
GAP LOCATION", GPT-BEG. "FS GAP LENGTH" gives EXTRAC. The actual value of
BEG is available as "FS REAL ADDRESS".
GPT and EXTRAC describe the "gap", a block of unused space in the middle of the
buffer. The real amount of space used by the buffer is Z-BEG+EXTRAC. BEGV,
PT, Z and ZV are "virtual" addresses in that they take no account of the gap.
To convert a virtual address to a real one, add EXTRAC to it if it is greater
than or equal to GPT. Real address 0 refers to the first character in word 0;
real address 5 refers to the first character in word 1, etc.
It is OK for the superior to alter those variables or the contents of the
buffer, if TECO is between commands or has returned because of ^K, FS EXIT or
^C; except that BEG should not be changed and the sum of Z and EXTRAC (the real
address of the end of the buffer) should not be changed, unless appropriate
relocation of other buffers and TECO variables is undertaken. TECO programs
need not worry about the gap, except for efficiency reasons or when
communicating with machine language programs, and they need never convert
character addresses to real addresses; TECO does all that.
Strings - internal format:
A string containing <n> characters takes up <n>+4 consecutive characters in
TECO. It need not start on a word boundary. The first four characters are the
string header; the rest, the text of the string. The header starts with a
rubout. The second character is <n>&177; the third, (<n>/200)&177; the fourth,
<n>/40000 (numbers in octal).
Buffers - internal format:
A buffer consists of a buffer-string, which points to a buffer frame, which
points to the buffer's text.
The buffer-string is similar to a string, and exists in a string storage space,
but begins with a "~" (ASCII 176) instead of a rubout. It has only three more
characers; the second is <addr>&177; the third, (<addr>/200)&177; the fourth,
<addr>/40000; <addr> being the address of the buffer frame.
The buffer frame is a seven-word block whose purpose is to save the buffer
block for buffers which are not selected. While a buffer is selected, the
buffer frame contents may not be up to date.
The first word of the frame contains a few flag bits in the left half. The
sign bit will be set to indicate that the block is in use as a buffer frame.
The 200000 bit is the GC mark bit and should be ignored. The 100000 bit, if
set, indicates that the buffer is really a qvector. The 40000 bit is the
"buffer modified" flag. These bits are only in the buffer frame, not the
buffer block (BEG).
Buffer and string pointers - internal format:
When a q-reg is said to hold a buffer or a string, it really contains a pointer
to the buffer or string. The pointer is in fact a number, distinguished from
other numbers by its value only! A range of the smallest negative numbers are
considered to be pointers (this is why QAUB copies a string pointer from QA to
QB without any special hair).
Numbers which are pointers are decoded by subtracting 400000000000 octal (the
smallest negative integer) to get a character address. This may either be the
exact address of a character in pure space (what :EJ loads into), or the
relative address of a character in impure string space (what "X" allocates
within. The char address of the start of impure string space is held in
location QRBUF). In either case, that character should be the rubout beginning
a string or the "~" starting a buffer-string. If the number, thus decoded,
does not point within either of those ranges, or doesn't point at a "~" or
rubout, then it is not a pointer--just a plain number.
For example, 400000000000.+(FS :EJPAGE*5*2000.) is a string pointer to a
string whose first character is at the very beginning of the last :EJ'd file.
If the file has the proper format (see "strings" above), that number may be put
in a q-reg and the string then executed with "M" or gotten by "G", etc. The
file might contain a buffer-string except that causing it to point to a
legitimate buffer frame would be difficult. Making it point to a counterfeit
buffer frame inside the file would lose, since TECO tries to write in buffer
frames.
Low Bits:
On ITS, the low bits of the words of a "text" file are generally ignored, but
on other systems such as BOTTOMS-10 any word whose low bit is 1 is effectively
not present in the file. Therefore, it is desirable not to set low bits of
text files. It is also necessary to be able to manipulate binary files,
reading and writing all the bits.
TECO never touches the low bits of files when they are read in. When a file is
written out, normally all the low bits are cleared. However, the @P command
outputs a file without touching the low bits. It is used to output binary
files.
When operating on binary files data in the buffer, you must be careful to avoid
operations which can clear the low bits of the words. Anything which moves
text except on word boundaries can shuffle the positions of the characters in
the words, and the low bits will be misplaced if not also cleared. You can
avoid such problems if you never insert or delete characters except in groups
of 5 or multiples of 5, starting at positions which are multiples of 5. In
this context, note that 5,0I will NOT clear the low bit; you must do 0,.-5FS
WORD or 0U:..Q(<n>) (or something else suitable) to do that.
How superiors can put text (and other things) into TECO:
A standard protocol for communication from a superior to TECO is hereby
defined, which allows the superior to request space in the buffer for inserting
text, or request that a file be loaded and a certain function be found. Macro
packages may supply functions to handle the requests instead of TECO's default
handler.
A superior can make a request whenever TECO has deliberately returned control
(by a ^K valret, FS EXIT or a ^C) by restarting TECO at a special place: 7
plus the address of the "buffer block", which address can be found in
accumulator 2 at such times. Save the old PC before setting it, since you must
restore the PC after the request is handled. The word after the starting
location (8 plus the buffer block address) is used for an argument.
There are two types of requests. If you wish to supply text for TECO to edit,
the argument should be the number of characters of text you need space for (it
may be 0). In that case, TECO will return (with an FS EXIT) after making at
least that much space in the buffer, after which you should restore the PC at
which TECO had stopped before you made the request. You can then insert the
text in the buffer and restart TECO.
If you want TECO to read in a file, supply a negative argument and be prepared
to supply TECO with JCL, when it asks with the standard .BREAK 12, describing
what it should do. When TECO does a .BREAK 16, (FS EXIT) you can assume it
has done its work, and should restore the old PC. The formats for the JCL
string are <filename><cr>, <filename>,<decimal number><cr>, and
<filename>,<function name><cr>. A decimal number should be the address within
TECO of the place to start editing. A function name can be anything that isn't
a number, and its interpretation is not specified.
TECO macro packages can supply a handler for requests from the superior by
putting it in FS SUPERIOR. It will receive the argument describing the type
of request as its numeric argument (^Y), and can read the JCL with FJ and do an
FS EXIT when finished. If FS SUPERIOR is zero, TECO's default actions will
be taken. Note that TECO's default handling of a request to load a file is to
do nothing.
TECO's character sets: (numbers in this section are in octal)
The most important TECO character sets are ASCII (7-bit) and the 9-bit TV set.
The contents of all files, strings, and buffers, and thus all TECO commands,
are in ASCII; 9-bit is used only for terminal input. Here is how TECO converts
between character sets:
14-bit to 9-bit conversion when characters are read in:
When a character is actually read from the terminal, it is in a 14-bit charac-
ter set which contains a basic 7-bit code, and the control, meta and top bits
(also shift and shift- lock, which are ignored since they are already merged
into the basic 7-bit character). TECO converts it to 9-bit as follows: if top
is 0, and the 7-bit character is less than 40 and not bs, tab, LF, CR or
altmode, then add control+100; then clear out top, shift and shift-lock. Thus,
TV uparrow comes in as top+013 and turns into 013; TV control-K comes in as
control+113 and stays control+113; TV "VT" comes in as 013 and turns into
control+113; TV control-VT comes in as control+013 and becomes control+113;
non-TV control-K comes in as 013 and becomes control+113; TV control-I comes in
as control+111 and stays control+111; TV "tab" comes in as 011 and stays 011;
TV control-tab comes in as control+011 and stays control+011; non-TV "tab" or
control-I comes in as 011 and stays 011.
The character 4110 (Top-H) is the HELP character; it is handled specially. It
is not changed, even when any other character would be converted to 9-bit or
7-bit. It is always returned as 4110. However, if FS HELP MAC is nonzero,
then 4110 typed AT ANY TIME will cause FS HELP MAC to be run. When FS HELP
MAC is run, the 4110 is otherwise ignored, so TECO will continue to wait for
input (unless FS HELP MAC sets FS REREAD to supply some). Only when FS HELP
MAC is zero will 4110 ever be returned to the user. ^R ignores 4110 (except
for running FS HELP MAC).
9-bit to ASCII, when TECO wants to read an ASCII code:
Input read in using "@FI", or read by the ^R-mode comand dispatch, is used as
9-bit. However, when input is read by "FI", or by the "^T" command reader, or
by TECO top level, it must be converted to ASCII as follows: meta is thrown
away; if control is 0 then nothing changes; otherwise, control is cleared and
the following actions performed on the 7-bit character that is left: rubout
stays the same; characters less than 40 stay the same; characters more than 137
have 140 subtracted; characters 100 to 137 have 100 subtracted; all others are
unchanged, except for 40 (Space) which becomes 0 (^@). Thus, control+111 (TV
control-I) becomes 011; control+011 (TV control-tab) becomes 011; and 011 (TV
tab, or non-TV control-I) stays 011. Similarly, TV uparrow, TV "VT", TV
control-K and non-TV control-K all become 013.
ASCII to 9-bit in FS ^RCMACRO and FS ^R INIT:
The ^R command dispatch table is indexed by 9-bit characters. For
compatibility with the time that it was not, the commands FS ^R CMACRO and FS
^R INIT, when not given the atsign modifier, accept an ASCII argument, and try
to have the effect of referring to the definition of that ASCII character--in
fact, they convert the ASCII character to 9-bit and then index their tables.
The conversion is as follows: If the character is less than 40, and is not bs,
tab, LF, CR or altmode, then add control+100. Thus, 013 (^K) becomes
control+113 (TV "VT" or control-K, not TV "uparrow"), which is just right.
Tab, etc. have a harder time doing the right thing, since both 011 control+111
are plausible ways that the user could type what corresponds to ASCII 011. The
solution chosen is to leave 011 ASCII the same in 9-bit, since the ^R-mode
definition of control-111 is to use 011's definition.
The initial ^R-mode definitions of all 9-bit characters:
All characters whose bottom 7 bits form a lower case letter are defined to
indirect through the corresponding upper case character. Their definitions are
all 40,,RRINDR, where RRINDR is the indirect-definition routine, and 40
specifies the character 40 less.
Control-BS and Control-H indirect through BS, and similarly for Tab and LF.
Control-CR and Control-Altmode (but not Control-M and Control-[) indirect
through CR and Altmode. An isomorphic indirection-pattern exists for meta
characters.
Control-, Meta- and Control-Meta-digits all accumulate into the numeric
argument.
Control-, Meta- and Control-Meta-Minus-sign all set the 4 bit in FS ^R ARGP,
thus negating the next command's arg.
All other meta characters are self-inserting. A few (mentioned above) are self
inserting because they go indirect through other meta characters.
All non-control non-meta characters, except for CR, altmode and rubout, are
self-inserting. CR inserts CRLF; altmode leaves ^R-mode; rubout deletes
backwards. Of the rest, ^H, ^I and ^J are defined to insert themeselves
straight away, while the rest are defined to be "normal" and do whatever FS ^R
NORMAL and FS ^R REPLACE say.
Control-rubout has its own special routine, which deletes treating spaces as if
they were tabs.
Control-digits update the numeric arg for the next command.
All other control characters not in the range control+101 through control+135
are errors.
Control-M inserts just a CR. Control-[ is an error.
The remaining control characters from control-101 to control-135 do what the ^R
command table says, or else are errors.
Neat hacks that are frequently useful:
1) To take an absolue value, use ^@^@. -1^@^@ and 1^@^@ are both 1. This
assumes that there is no pre-comma argument.
2) When there is just a pre-comma argument, :^@ will make it a post-comma
argument instead. There will be zero as a pre-comma argument, but another ^@
will flush that. Thus, :^@^@ gets a pre-comma argument as a post-comma
argument with no pre-comma. If there is a post-comma argument already, start
with *0 to clear it first, giving *0:^@^@.
Since many commands ignore pre-comma arguments, simply :^@ may be enough.
3) ",0^@" negates its argument, like "*(-1)".
4) The easiest way to compute the maximum of two quantities is with F^@, as in
QA,QBF^@. This, however, returns the other one as a pre-comma argument. For
the minimum as a post-comma arg, add :^@.
TECO program writing standards:
1) Each line that doesn't begin inside a string argument should be indented
with at least one space, preferably with a number of spaces indicating how deep
in conditionals and iterations it is.
2) The semantic content of one line of TECO program should be no greater than
that of one line of any other language, if the program is to be understandable.
In other words, break lines frequently--and put a comment on each line. There
should be spaces between logical groups of commands, every few characters, as
in "3K J IFOO", which also shows how long a line should be.
3) The standard way to write a comment is to make it look like a tag:
!*<comment>!.
4) Follow value-returning commands with "W"'s or CRLFs when the value is not
used for anything.
5) An example of a well-commented TECO program is RMAIL. See EMACS1;RMAILX >
and RMAILZ >. Note that these are written in EMACS compressor format.
TECO program debugging aids:
1) Trace mode causes all TECO commands to be typed out as they are executed.
See the "?" command. A good technique is " 1F[TRACE MA " for running q-reg A
in trace mode.
2) Using FS STEP MACRO you can cause TECO to pause at each line, displaying
the buffer and waiting for input before continuing execution. This works best
when lines are short, as they ought to be anyway.
3) Break-loops on errors are available, by setting FS *RSET to nonzero, or by
using Q..P.
4) It is easy to edit a "FTHere I am" or "Q0=" into the program and re-execute
it.
5) If the standard top level is in use, "?" typed in after an error will cause
a printout of a short section of command string up to the point of the error.
User break loops in Q..P can use FS BACKTRACE to do similar or better things.
6) Setting FS .CLRMODE to 1 disables the ^L and F+ commands, which normally
clear the screen. This may be useful for debugging programs that wipe out
their trace output.
Local Modes:
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