#!/bin/bash

  logrotate ..... # rotate out /data/file.txt
  perl -x $0 $@ > /data/file.txt 2>&1
  mail -s "file.txt" me@example.com < /data/file.txt
  echo "Job done. Errors:"
  grep ERROR /data/file.txt

exit
#######
#!/usr/bin/perl

# do whatever perl-friendly tasks -- process some files, do calculations, call CPAN modules for heavy lifting, whatever.