#!/usr/bin/perl -w
use strict;

die qq[You need to run "pl2bat $0" first.\n]
  unless  <DATA> =~ /^:endofperl$/i;
open DATA, "+< $0"
  or  die "Can't update $0: $!\n";
while(  <DATA>  ) {
    last   if  /^:endofperl$/i;
}
seek( DATA, 0, 1 );
@ARGV= qw( This is a test )   unless  @ARGV;
print DATA "SET PARENT=@ARGV\n";
truncate( DATA, tell(DATA) );
warn "Setting %PARENT% in the parent shell's environment.\n";
exit( 0 );