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DIRECT.DOC -- Changes from V6(441) to V7(502)
February, 1986
































COPYRIGHT (C) 1972,1974,1977,1979,1981,1986
DIGITAL EQUIPMENT CORPORATION, MAYNARD, MASS.


THIS SOFTWARE IS FURNISHED UNDER A LICENSE FOR USE ONLY  ON  A  SINGLE
COMPUTER SYSTEM AND MAY BE COPIED ONLY WITH THE INCLUSION OF THE ABOVE
COPYRIGHT NOTICE.  THIS SOFTWARE, OR ANY OTHER COPIES THEREOF, MAY NOT
BE PROVIDED OR OTHERWISE MADE AVAILABLE TO ANY OTHER PERSON EXCEPT FOR
USE ON SUCH SYSTEM AND TO ONE  WHO  AGREES  TO  THESE  LICENSE  TERMS.
TITLE  TO  AND  OWNERSHIP OF THE SOFTWARE SHALL AT ALL TIMES REMAIN IN
DEC.

THE INFORMATION IN THIS SOFTWARE IS SUBJECT TO CHANGE  WITHOUT  NOTICE
AND  SHOULD  NOT  BE  CONSTRUED  AS  A COMMITMENT BY DIGITAL EQUIPMENT
CORPORATION.

DEC ASSUMES NO RESPONSIBILITY  FOR  THE  USE  OR  RELIABILITY  OF  ITS
SOFTWARE ON EQUIPMENT WHICH IS NOT SUPPLIED BY DEC.

DIRECT.DOC -- Changes from V6(441) to V7(502)                   Page 2
February, 1986


1.0     SUMMARY

DIRECT version 7  runs  on  all  monitors.   It  has  been  tested  on
7.02/7.03.  DIRECT version 7 fully supersedes all previous versions.

DIRECT version 7 is documented in the  system  commands  manual.   See
also the help file DIRECT.HLP.

DIRECT performs a directory listing of any  of  several  media.   Most
commonly,  it  is  used to obtain a directory listing of the disk.  It
can produce a similar listing of a FAILSAFE, FRS, or BACKUP mag  tape.
DIRECT  can  also analyze a tape for the presence of tape labels (both
in ASCII and SIXBIT) as well as SAVE files.  DIRECT can also produce a
listing  of  DECtapes  and  of  TMPCOR.   The directory listing can be
formatted for speed, compactness, completeness (even extreme  detail),
or for sorting by SORT.



2.0     EXTERNAL CHANGES

The main reason for DIRECT version  7  is  to  utilize  the  new  SWIL
library   ("Scan-Wild-I/o-Library,  which  functionally  replaces  the
version 7 SCAN, WILD, and HELPER modules), as  well  as  to  fix  some
minor bugs.

Following is a list of the "external" or  visible-to-the-user  changes
in DIRECT version 7.


2.1     Listing Format

The directory output listing format has been  "standardized"  for  all
supported  listing  device-types.   In  particular, DECtape and TMPCOR
listings are now formatted just like disk listings, and obey the  same
rules  (and are controlled by the same set of switches, such as /FAST,
/NORMAL, /WIDTH, etc.).

Two new switches have been added, /DTA and /TMPCOR to force  directory
listings  of DECtapes and TMPCOR to be formatted as they used to be in
versions of DIRECT previous to version  7.   Additionally,  the  /FDTA
switch was removed (/FAST works).


2.2     /DETAIL listing format

The /DETAIL listing  format  now  includes  the  new  .RBTYP,  .RBBSZ,
.RBRSZ,  and  .RBFFB  "file  type/format" words, as well as the .RBIDT
BACKUP "incremental date/time" word.


2.3     Magtape buffers

DIRECT version 7 now automatically builds buffers for magtape devices,

DIRECT.DOC -- Changes from V6(441) to V7(502)                   Page 3
February, 1986


and  will  expand  the  buffers  as  needed  in order to read in large
records  (DIRECT  only  checks  the  first  tape  record,   subsequent
oversized  records will report the usual "Block Too Large" I/O error).
Alternatively, the /BLOCKSIZE switch may be used to explicitly specify
the  size  of  buffers for DIRECT to build for the magtape device.  If
/BLOCKSIZE is used, then DIRECT will NOT automatically expand  buffers
to read the tape.

Due to the addition of the /BLOCKSIZE switch (in  the  SWIL  package),
the  /BLOCKS  switch in DIRECT has been removed, and replaced with the
/NOWORDS switch.


2.4     File specification and file expression syntax and semantics

While the command syntax and semantics remain  essentially  unchanged,
there are a few minor changes evident to the user.

2.4.1   Node names

SWIL allows node names to be included in file specifications (you  can
even  wildcard  the  node  names), but DIRECT supports only local host
directory listings (use the NFT program for remote  network  directory
listings),  and  will  issue  an error message if you specify any node
other than the local host.

2.4.2   Device names

SWIL allows  device  names  to  be  wildcarded  (e.g.,  "DSK?:").   By
default, only mounted disk structures are matched to wildcarded device
names.  You can specify the /ANYDEVICE switch in conjunction with  the
wildcarded device name and SWIL will match against all devices on that
system, including terminals, tapes, etc.  To match only disk structure
names,  the /DSKONLY switch may be used.  Logical names, ersatz device
names, and pathological device names are never matched.

2.4.3   Pathological devices

SWIL fully supports pathological device name definitions.

2.4.4   Guide words

SWIL implements several  new  'GUIDE'  words  used  in  building  file
expressions.   Following  is  the  list  of  currently supported guide
words:


     1.  AND    Match if both simple specs match

     2.  OR     Match if either simple spec matches

     3.  NOT    Match if first spec but not second spec

DIRECT.DOC -- Changes from V6(441) to V7(502)                   Page 4
February, 1986


     4.  BEGIN  Begin matching with secondary file

     5.  END    End matching with secondary file

     6.  IFAND  Match if secondary file exists

     7.  IFNOT  Match if secondary file doesn't exist

     8.  IFSAME Match if secondary file is the same

     9.  IFDIFF Match if secondary file is different

    10.  IFOLDE Match if primary file is older than secondary file

    11.  IFNEWE Match if primary file is newer

    12.  IFBIGG Match if primary file is bigger

    13.  IFSMAL Match if primary file is smaller


For example, "*.* 'IFAND' SYS:" selects all  your  files  (first  spec
defaults  to  "DSK:[-]")  which also exist on SYS:  (defaults to *.*).
"*.* 'IFSAME' SYS:" operates in a similar manner, but the extant  file
on SYS:  must also be the same length, logical creation date/time, and
the same I/O mode.  "*.* 'IFBIGGER' SYS:" would match any files  which
exist  on  SYS:  and are smaller than your counterpart file.  The last
five operators are  considered  "successful"  if  the  secondary  file
doesn't  exist  (i.e.,  "BLAH.BAR  'IFBIGGER'  SYS:"  wins if the file
doesn't exist on SYS:).


2.5     /[NO]SBRMSG switch

The /[NO]SBRMSG switch has been added to control the issuance  of  the
[new-to-version-7]  "DRTSBR  Skipping BACKUP repeater record" message.
The default is /NOSBRMSG.



3.0     KNOWN BUGS AND DEFICIENCIES

If  /SORT  on  several  file  specs  with  distinct  directories,  the
directories  will  not  be  listed  (even  if  concatenated).  This is
because  of  the  notion  that  distinct  directories   can   not   be
concatenated   (in   WILD),  and  that  distinct  requests  to  DIRECT
(separated by commas) are treated separately.



4.0     INSTALLATION INSTRUCTIONS

Compile with JOBDAT, MACTEN, UUOSYM, and SWIL as universals  on  UNV:,
and load with SWIL library .REL file on REL:.  For example:

DIRECT.DOC -- Changes from V6(441) to V7(502)                   Page 5
February, 1986


     .LOAD DIRECT



5.0     INTERNAL CHANGES

The internal changes to  DIRECT  are  available  in  the  source  file
DIRECT.MAC, near the begining of the file under the subtitle "Revision
History".



6.0  SUGGESTIONS

SORT CAPABILITIES SHOULD BE BUILT IN.

(SPR 10-9943) ADD A SUPER GRAND TOTAL TO COVER AN ENTIRE MAG TAPE.

(SPR 10-14,278) HAVE /DETAIL/SORT FORMAT OUTPUT ON  A  LINE  PER  FILE
BASIS, CONDUCIVE TO SORTING.



7.0  SPECIFICATIONS 7.1 Find File Format

DIRECT can write two parallel  binary  "find  files"  suitable  for  a
program  to  later read in order to find where certain files are kept.
These "find files" can also be read by DIRECT by specifying  /FIND  in
the command line.

This facility is useful for maintaining online directories of normally
offline  files  (either  disk  or  BACKUP magtapes).  The capabilities
provided  with  DIRECT  version  7  do  not  provide  any  means   for
identifying  (for  example)  on  which  reel  of  a  BACKUP  saveset a
particular file resides (an RP06 can fill 6 2400' tapes at 1600bpi) or
even  the  tape  REELID.   DIRECT's  "find"  ability  is  really  only
concerned with identifying  which  offline  disk  structure(s)  has  a
particular file.

The /FNDBLD switch will cause DIRECT to write the "find  files";   the
/FIND  switch  will  cause  DIRECT  to read the "find files";  and the
/FNDDAT switch identifies the "find files" to be used by /FIND.

The first and shorter "find file" contains just filename and extension
information.   This  file is generated with an extension of .FPF (Find
Pointer File).   This  file  is  intended  only  for  quickly  finding
possible  matches  -  to  really  identify  a file requires the second
(.FDF) file.  Each file entry in the .FPF file is two words long:

     00/ File name in SIXBIT
     01/ Extension in SIXBIT,,0

The second file contains all the necessary retrieval  information  for
each  file.   This  file  is generated with an extension of .FDF (Find

DIRECT.DOC -- Changes from V6(441) to V7(502)                   Page 6
February, 1986


Data File).  Each file entry in the .FDF file is sixteen words long:

     00/ Node name in SIXBIT (reserved for future)
     01/ Device/structure name in SIXBIT
     02/ UFD (binary)
     03/ SFD 1 (SIXBIT)
     04/ SFD 2 (SIXBIT)
     05/ SFD 3 (SIXBIT)
     06/ SFD 4 (SIXBIT)
     07/ SFD 5 (SIXBIT)
     10/ File name (SIXBIT)
     11/ Extension (SIXBIT),,protection and mode (LH .RBPRV)
     12/ Word count (binary)
     13/ Creation time (universal format)
     14/ Access time (universal format)
     15/ Version (binary)
     16/ 0 (reserved for future)
     17/ 0,,Checksum (binary)


[End of DIRECT.DOC]