A variation of Chuck Houpt's 2007 cronic script

cronic

#!/bin/bash

# Cronic v2 - cron job report wrapper
# Copyright 2007 Chuck Houpt

CRONIC_LOG=${CRONIC_LOG:-/sitelogs/cronic/cronic.$LOGNAME.log}
CRONIC_LOCK=${CRONIC_LOCK:-/tmp/cronic.$LOGNAME.lock}

trim() { echo $1; }

HOST=$(trim `hostname`)
USER=$(trim `whoami`)

# N.B. On ubuntu, `sudo apt-get install heirloom-mailx` for the version of /usr/bin/mail
# for which this script is written

MAIL=mail
MAILTO="a@b.net"
SMTP="smtp.gmail.com"
FROM="$USER@$HOST"

# http://www.gnu.org/software/bash/manual/html_node/The-Set-Builtin.html
set +e # Do not exit immediately if certain commands return non-zero status.
set -u # Treat unset vars and params besides special params .@. or .*. as an error when expanding params.

OUT=/tmp/cronic.$USER.out.$$
ERR=/tmp/cronic.$USER.err.$$
TRACE=/tmp/cronic.$USER.trace.$$
MSG=/tmp/cronic.$USER.msg.$$

"$@" >$OUT 2>$TRACE

EXITCODE=$?

PATTERN="^${PS4:0:1}\\+${PS4:1}"
if grep -aq "$PATTERN" $TRACE ; then
    ! grep -av "$PATTERN" $TRACE > $ERR
else
    ERR=$TRACE
fi


if [ $EXITCODE -ne 0 -o -s "$ERR" ] ; then
    (
    echo "On host $HOST, cronic detected failure or error output for the command:"
    echo "$@"
    echo
    echo "EXIT CODE: $EXITCODE"
    echo
    echo "ERROR OUTPUT:"
    cat "$ERR"
    echo
    echo "STANDARD OUTPUT:"
    cat "$OUT"
    if [ $TRACE != $ERR ] ; then
        echo
        echo "TRACE-ERROR OUTPUT:"
        cat "$TRACE"
    fi
    ) > $MSG

    $MAIL -V < /dev/null >/dev/null 2>&1
    if [ $? -eq 0 ] ; then # Sending with Ubuntu mail...
        cat $MSG | tr '\r' '\n' | $MAIL -s "For '$1', cronic detected either non-zero exit or STDERR output" -S from="$FROM" -S smtp="$SMTP" $MAILTO
    else # Sending with RHEL mail...
        # Must be a non-heirloom-mailx, so doesn't understand -S option.  Hopefully, "from" and "smtp" are configured OK...
        cat $MSG | tr '\r' '\n' | $MAIL -s "For '$1', cronic detected either non-zero exit or STDERR output" $MAILTO
    fi
fi

(
  flock -w 5 200
  mkdir -p /sitelogs/cronic 2>/dev/null
  if [ $? -ne 0 ]; then CRONIC_LOG=cronic.log;  fi
  echo "At $(date) executed:" >> $CRONIC_LOG
  echo "$@" >> $CRONIC_LOG
  echo "Returned exit code $EXITCODE" >> $CRONIC_LOG
  echo >> $CRONIC_LOG
  echo "STDOUT:" >> $CRONIC_LOG
  cat "$OUT" >> $CRONIC_LOG
  echo >> $CRONIC_LOG
  echo "STDERR:" >> $CRONIC_LOG
  cat "$ERR" >> $CRONIC_LOG
  echo >> $CRONIC_LOG
  printf -v f "%20s" ; printf "%s\n" "${f// /-}" >> $CRONIC_LOG
  echo >> $CRONIC_LOG

) 200>$CRONIC_LOCK

rm -f "$OUT"
rm -f "$ERR"
rm -f "$TRACE"
rm -f "$MSG"