Invoke jobs in parallel and capture the output and exit statuses

parallel_jobs.sh

#!/bin/bash

###############################################################################
# This script invokes all jobs in parallel and organizes the output by job
#
# Author: Colin Mollenhour
###############################################################################

[ -z "$1" ] && { echo "Usage: $0 <commands_list>"; exit 1; }
wd=$(pwd)
[ -f errors ] && rm -f errors
while read line; do
  output=$wd/$(echo "$line" | md5sum - | awk '{print $1;}')
  (
    echo "COMMAND: $line" > $output
    $line 2>&1 >> $output
    status=$?
    echo "-------------- Completed on $(date) with status $status" >> $output
    [ $status -eq 0 ] || cat $output >> $wd/errors
  ) 2>&1 >> $output &
done < <(grep -v '^$\|^\s*\#' $1)
wait
[ -f errors ] && { echo "One or more tasks incurred errors:"; cat errors; exit 1; }
exit 0