[Info-vax] Compression tool

[Stephen Hoffman]

On 2014-02-26 05:29:17 +0000, ajithb98 at gmail.com said:

> Any compression or archiving tool present in built in VMS 7.3?

Depending on what you're looking to do here — terse questions can be 
surprisingly tough to answer — probably not.  This assuming you've 
already done the basic research here and have looked at BACKUP and 
discarded its use for your purposes.     Accordingly, probably the best 
available is to acquire the current versions of zip (version 3) and 
unzip (version 6), and use the "-V" option on the zip.

You can fetch copies of zip and unzip from the OpenVMS archives at 
<http://www.process.com>, and from other locations around the 'net — 
the stuff was available at info-zip.org as well, but was harder to find 
when last I went looking over there.  (Which was a while ago.)

Technically BACKUP can archive and there are tools to read those 
savesets on other platforms, but the RMS file formats can get the 
access tangled as even the RMS sequential files aren't necessarily as 
transportable as might be realized, and the more complex RMS formats 
would require tools on the target platform to unpack.

The DCX data compression API is baked into OpenVMS, but BACKUP didn't 
get around to using that until much more recently than V7.3; officially 
only V8.4 has BACKUP compression, IIRC.  VMS doesn't have anything akin 
to zip, lz, 7zip or other such baked in; DCX isn't very effective 
compression by present standards, and there's no command utilities for 
it.

If this request is strictly for native VMS archiving and not 
transporting data and you didn't already find BACKUP, then you might 
want to spend some time in the system management manuals — that'll help 
you manage OpenVMS rather more effectively.  
<http://www.hp.com/go/openvms/doc> and look in the OpenVMS 
documentation shelf — there are two volumes covering system management, 
and the System Manager's Utilities manual covers BACKUP and 
BACKUP$MANAGER in some detail.


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