[Info-vax] difference in files being copied by scp from Unix to VMS

[Bob Koehler]

In articl03f0617$0$30920$c3e8da3 at news.astraweb.com>, JF Mezei <jfmezei.spamnot at vaxination.ca> writes:
> 
> *when VMS receives the file, it might tag on those extra bytes.

   Most network utilities for VMS store binary data as 512 byte records.
   So if the last byte received is somewhere in the middle of the
   block zero padding is added after the last data byte.

   Many of the files that VMS treats as binary need to be 512 byte
   blocks, others don't.  Some network utilities allow the user to
   control how binary data is stored (e.g. record size in the Multinet
   FTP client), others don't.

   I ran into this with an FTP binary transfer via UCX' client years
   ago.  We were not able to meet the customer's original requirement
   that we prove the received file identical to the remote copy, since
   it wasn't.  The customer was happy that we could prove all the
   bytes prior to the pad were identical, right up to the number of
   bytes the remote system claimed for the file size.

   It is, of course, possible to fix the file after receipt, just not
   typically necessary to do so.  RMS keeps a value in the file header
   which locates the last data byte in the last disk block; or the
   file can be rewritten in a different format.