HP OpenVMS Systems

ask the wizard
Content starts here

Maximum DCL Buffer Sizes? (Symbols, PIPE)

» close window

The Question is:

I am trying to use PIPE to run the output from rmu/unload (rdb) throught a
 filter program.
e.g. pipe rmu/unload ... database table sys$output: | filter > file.dat
This works fine when the record size output by rmu is less than than 256
 characters long, but once it reaches 256 it produces no output in the file.dat
 file at all.
I have read that there is a buffer limit of 256 for DCL pipe commands.
Does this apply to data fed through the pipe too ? If so, is there any way to
 change the 256 limit, using a sysgen parameter or a setting on the MPAnnn:
 device created by the pipe.
Surely for the PIPE command to be of any use when used for "filter"
 applications as described in the VMS docs. this should at least be
 configurable somewhere.

The Answer is :

  Yes, and no, respectively.  The sizing of internal DCL buffers is
  a very old scheme, and the buffers are small by current standards,
  and the maximum sizes for the DCL symbols and the DCL command lines
  are largely hard-wired into the DCL interpreter.

answer written or last revised on ( 29-MAR-2002 )

» close window