19.0.1 `util_filter'
--------------------

util_filter(COMMAND,INPUT)
     :  It executes the filter program COMMAND with the INPUT  and
     returns the output of the filter as a string.

util_filter(COMMAND,INPUT | ENV=key0)
     : This function allows optional variables   ENV
Example:
      util_filter("sort","cat\ndog\ncentipede\n");

