Qualifier

/OUTPUT
      /OUTPUT=filespec

   Specifies the name of the file to which the command procedure
   output is written. By default, the output is written to the
   current SYS$OUTPUT device. The default output file type is
   .LIS. The asterisk (*)  and the percent sign (%) wildcard
   characters are not allowed in the output file specification.
   System responses and error messages are written to SYS$COMMAND
   as well as to the specified file. The /OUTPUT qualifier must
   immediately follow the file specification of the command
   procedure; otherwise, the qualifier is interpreted as a parameter
   to pass to the command procedure.

   You can also redefine SYS$OUTPUT to redirect the output from a
   command procedure. If you place the following command as the
   first line in a command procedure, output will be directed to the
   file you specify:

   $ DEFINE SYS$OUTPUT filespec

   When the procedure exits, SYS$OUTPUT will be restored to its
   original equivalence string. This produces the same result
   as using the /OUTPUT qualifier when you execute the command
   procedure.