#!/bin/bash
# logevents.sh, by Stephane Chazelas.

# Event logging to a file.
# Must be run as root (for write access in /var/log).

ROOT_UID=0 # Only users with $UID 0 have root privileges.
E_NOTROOT=67 # Non-root exit error.


if [ "$UID" -ne "$ROOT_UID" ]
then
echo "Must be root to run this script."
exit $E_NOTROOT
fi


FD_DEBUG1=3
FD_DEBUG2=4
FD_DEBUG3=5

# Uncomment one of the two lines below to activate script.
# LOG_EVENTS=1
# LOG_VARS=1


log() # Writes time and date to log file.
{
echo "$(date) $*" >&7 # This *appends* the date to the file.
# See below.
}



case $LOG_LEVEL in
1) exec 3>&2 4> /dev/null 5> /dev/null;;
2) exec 3>&2 4>&2 5> /dev/null;;
3) exec 3>&2 4>&2 5>&2;;
*) exec 3> /dev/null 4> /dev/null 5> /dev/null;;
esac

FD_LOGVARS=6
if [[ $LOG_VARS ]]
then exec 6>> /var/log/vars.log
else exec 6> /dev/null # Bury output.
fi

FD_LOGEVENTS=7
if [[ $LOG_EVENTS ]]
then
# then exec 7 >(exec gawk '{print strftime(), $0}' >> /var/log/event.log)
# Above line will not work in Bash, version 2.04.
exec 7>> /var/log/event.log # Append to "event.log".
log # Write time and date.
else exec 7> /dev/null # Bury output.
fi

echo "DEBUG3: beginning" >&${FD_DEBUG3}

ls -l >&5 2>&4 # command1 >&5 2>&4

echo "Done" # command2

echo "sending mail" >&${FD_LOGEVENTS} # Writes "sending mail" to fd #7.


exit 0