Re: Compress IFS Files

I'm trying to use compress w/this result;
 
compress -v /home/fbtest                                                        
         
compress: 001-2104 Error found reading from file /home/fbtest. Operation not 
supported.  
$                                                                               
             
 
Is the syntax wrong?  
 
Thanks, Frank
 
 
-----Original Message-----
From: midrange-l@xxxxxxxxxxxxxxxx
To: midrange-l@xxxxxxxxxxxx
Sent: Mon, 5 Mar 2007 1:08 PM
Subject: Re: Compress IFS Files


Hello Frank,

Hello, what do you think is the best way to compress IFS files?
Something like cprobj would be nice since I don't want to change
these files and they may be used again at some point.

The advantage that CPROBJ has over any IFS tool (that I can think of) is 
that CPROBJ will automatically decompress an object if the user tries to 
access it.  By contrast, you'd have to manually decompress an IFS file 
prior to accessing it.

There are a lot of ways to compress an IFS object.

a) The JAR command that you mentioned would work.  However, JAR also 
creates an archive in addition to compressing it.  And, by default, it 
adds a Java manifest to the object.

b) The "compress" tool in QShell

c) The gzip tool is arguably the most commonly used compression tool on 
Unix systems for this type of thing. (It provides better compression 
than the "compress" tool.) You can download gzip for QShell at the 
following link:
http://www-03.ibm.com/servers/enable/site/porting/iseries/overview/gnu_utilities.html

d) If you want even better compression, the bzip2 tool is also very 
commonly used on Unix systems.  In fact, you could argue that bzip2 is 
replacing gzip as the most popular one.  Though, in my experience, bzip2 
is much slower than gzip and only saves a few bytes...   It's available 
for PASE at the following link:
http://aixpdslib.seas.ucla.edu/packages/bzip2.html

e) If you want something compatible with PKZIP (which is really only 
useful if you want to exchange data with Windows computers, IMHO) 
there's also InfoZip, which is IMHO, much nicer than JAR.  You'll find 
InfoZip for PASE at the following links:
http://aixpdslib.seas.ucla.edu/packages/zip.html
http://aixpdslib.seas.ucla.edu/packages/unzip.html

This is probably only the tip of the iceberg, but I've tried to provide 
the most commonly used solutions for compressing stream files.  Hope 
they help...