Better Compression Using RAR
Build Bigger Archives
Backup To Your Hard Drive
by Peter Skye
The following discourse about file compression software first appeared on the SCOUG-Help list on May 15, 2002. If you need more than what PKZip can deliver, you should take a look at RAR.
A while back I complained on the SCOUG-Help mail list that PKZip wouldn't compress my many files (I wanted to use it to back up to a hard drive) due to the OS/2 version only allowing about 2,000 files in an archive.
A new version 3.00 of RAR, an alternate compression utility, has been posted to Hobbes. My preliminary tests show it handles locked files such as \DMISL\BIN\sldb.dmi (which COPY, XCOPY and PKZip won't do) and it doesn't have PKZip's OS/2 constraint of a maximum number of files.
The file date of the RAR executable is 14May2002. You can get the files at:
and eventually they'll be moved to
This rar300.zip file contains the exact same OS/2 and DOS files (I checked) that are on the RAR home site at http://www.rarlab.com/, but the rarlab.com version of the files are in DOS executable format while the Hobbes files are in .zip format. The DOS executable format won't extract the files if you run it in a directory path with a long filename (such as C:\MyExecutables\RAR\); you can either extract to an "8.3" path or use the .zip version.
The readme.txt has some important information that can be a bit confusing. Here are the unconfused infobits:
- You only need the rar32.exe file (you can ignore the emx.exe and rsx.exe files which are for DOS support).
- For full documentation you have to download the Windows version, so go to
http://www.rarlab.com/ and click to the Download frame, then download the WinRAR 3.00 version (wrar.exe). When I tried running this file, winrar.exe gave me an execution error (the file is Win32 format) so I couldn't get the documentation. However, author Eugene Roshal emailed me with a simple fix -- use the OS/2 rar32.exe executable to
unpack just the documentation from the Windows version. Here's the command:
rar32 x wrar300.exe rar.txt
The following five "locked"(?) files were handled "sort of" successfully by RAR (these files cause SYS0032 errors in other apps):
RAR successfully archived the data in these files but *did* report that it couldn't get the Extended Attributes for some of them (only LOG0001.DAT actually had any extended attributes). Also, SWAPPER.DAT couldn't be archived by RAR (not that I want it, but I was testing).
The file LOG0001.DAT which RAR couldn't get the Extended Attributes for is the error log file used by SYSLOG and SYSLOGPM; documentation is in CMDREF.INF and SYSLOGPM.HLP. I used PMSEEK to find this, which led me to run SYSLOGPM (SYSLOG just runs SYSLOGPM) which I had never done before. I was quite surprised at all the system errors I'm getting in PMWP.DLL (plus something called a "File wrapped" error), and as a side note SYSLOGPM should become part of your weekly maintenance procedure (run it right now to see your own system error log). SYSLOGPM.EXE is in the \OS2\ directory.
Both RAR and PKZip are shareware.
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