print linenumber where error occurs in Pig

check_pig_error.sh

#!/bin/bash

usage() {
    cat <<USAGE
 usage: $(basename $0) [-p <param_name>=param_value] [-m <file_name>] [-x exectype] <script>
        Execute the script with access to grunt environment.
        -p <param_name - See parameter substitution for details.
        -m <file_name> - See parameter substitution for details.
        -x <exectype> - Set execution mode: local|mapreduce, default is mapreduce.
        script - Script to be executed.
USAGE
    exit 1
}

while getopts p:m:x: OPT; do
    case $OPT in
        p) param="$param -param $OPTARG";;
        m) param_file="$param_file -param_file $OPTARG";;
        x) exectype="-x $OPTARG";;
    esac
done
shift $(($OPTIND - 1))

[ $# -eq 1 ] || usage
script=$1

tmpfile=$(mktemp /tmp/$(basename $script).XXXXXXXXXX)
# remove characters except ASCII characters
perl -nle 's/[^\x00-\x7F]//g; print' $script >$tmpfile

line_num=$(echo run $param $param_file $tmpfile | pig $exectype | wc -l)
echo at line $(($line_num - 1)) 1>&2
rm $tmpfile