Newsgroups: comp.sys.ibm.pc.misc
Subject: Compress Huge File 1/3
Date: Thu, 10 Dec 1992 13:49:02 -0700

HM>Does anyone know how to use compression like pkzip, arj, ahl, etc
HM>to compress a huge file/directories (I know this part) and
HM>then save them to disk?

As others have already suggested, follow the instructions for using
ARJ in this manner.  Another suggestion for using PKZIP was posted
in this conference.  It is as follows:

   From: H. D. Knoble
     To: All
   Area: IBM.PC.MISC

As it turns out, DOS (4.0 and 5.0 at least) BACKUP command tries to
compress a bit the files it's backing up. If, however, the file is
already highly compressed, e.g., a PKZIP (by Phil Katz) file, then
DOS BACKUP will not change one bit in the file when it creates
BACKUP.001, BACKUP.002, ... , except for splitting across diskette
if necessary. Thus if one uses PKZIP indexed backup (by providing
PKZIP with a file that contains only those filespecs that you wish
to PKZIP) and PKZIP creates a ZIP file that BACKUP will backup to
one diskette, then the file BACKUP.001 would in fact be also a ZIP
file; e.g., PKUNZIP -v A:\BACKUP.001 | MORE  will display its
contents.

Because so many people recently seem to be suffering the loss of
personal data (versus re-installable files of a package they may use
to create that personal data) I offer a simple code and
documentation here, say ZBACKUP.BAT and ZBACKUP.HLP, to help some of
you address this kind of painful experience.  Unlike PSU mainframe
computers, each person using a microcomputer is responsible for the
integrity of their own personal files.  Given an ASCII index file of
DOS filespecs, ZBACKUP.INX, that you create, the actual code
(including taking a snap-shot of DIR C:\*.*) amounts to four four
DOS commands like (assuming enough space on C: to hold the zip
file):

DIR C:\ > C:\C-Disk.DIR
PKZIP -a -P -J -w -z C:\ZBACKUP.ZIP C:\C-Disk.DIR @C:\ZBACKUP.INX
BACKUP C:\ZBACKUP.ZIP A:
ERASE C:\C-DISK.DIR

Including documentation, some integrity checks, etc.  the files, these
four commands are implemented in ZBACKUP.BAT which is documented in
ZBACKUP.HLP; an example of ZBACKUP.INX (the index file unique to each
unique person's "critical" files) also follows.  Each file appears below
and is separated by a line of dashes (---'s).  From PSUVM you can save
this Netnews file that you are now reading on your CMS E-Disk by moving
the cursor to the command line and issuing: SAVE ZBACKUP MEMO E  from where
you can then edit and download.  The binary file ZBACKUP.ZIP containing
these three files (4100 bytes long) also resides on the PSUVM Kermit
Product Disk (which can be accessed by issuing the command: PRODUCT KERMIT
downloaded and unzipped from there).

   --------------------------ZBACKUP.BAT follows-------------------------
@Echo Off
REM ***********************************************************************
REM  ROUTINE:   ZBACKUP.BAT
REM  PURPOSE:   PKZIP Backup all files specified in file C:\ZBACKUP.INX to
REM             C:\ZBACKUP.ZIP, then to 1.44M diskette using DOS BACKUP.
REM  PACKAGE:   Backup of Personal PC files
REM  CALLS:     PKZIP and DOS BACKUP command.
REM  FILES NEEDED: ZBACKUP.INX, ZBACKUP.HLP
REM  CALLED BY: ZBACKUP    or   ZBACKUP ?  to display Help.
REM  MODIFY:    A:, the floppy drive, may be changed to any desired drive.
REM  AUTHOR:    H. D. Knoble, HDK@PSUVM, 02/13/92
REM
************************************************************************
if "%1" == "?" GoTo Help
if "%1" == "" GoTo Next
Echo .
Echo $$Error: Invalid Syntax: %0 %1 %2 %3 %4 %5 %6 %7 %8 %9
Echo .
GoTo Done
:Next
if exist C:\ZBACKUP.INX GoTo BackThem
Echo .
Echo $$Error: C:\ZBACKUP.INX not found.
Echo .
GoTo Done

:BackThem
REM a(add), P(include pathnames), J(don't mask hidden/system/ronly files)
REM w(include hidden/system/ronly files), z(ask for zip comment).
DIR C:\ > C:\C-Disk.DIR
PKZIP -a -P -J -w -z C:\ZBACKUP.ZIP C:\C-Disk.DIR @C:\ZBACKUP.INX
if errorlevel 1 GoTo WrapUp
if not exist C:\ZBACKUP.ZIP Goto WrapUp
Echo .
Echo ZBACKUP: To bypass DOS BACKUP press Ctrl-Break at its prompt.
Echo          DOS BACKUP beginning now...
BACKUP C:\ZBACKUP.ZIP A:
if errorlevel 1 GoTo Done
Echo .
Echo You may now ERASE C:\ZBACKUP.ZIP after verifying C:\ZBACKUP.ZIP
is backed up.
Echo To verify this: issue DIR A:BACKUP.* for each diskette BACKUP
    called for;

--CONTINUED...

 * OLX 2.1 TD * May peace and joy be yours this holiday season!

 * Origin: Taiwan Missionary BBS (12:2000/886.0)

Newsgroups: comp.sys.ibm.pc.misc