#!/bin/sh
#
# NAME:		cronEdit
#
# SYNTAX:	cronEdit <-a|-d > <cron file>
#
# DESCRIPTION:	Edits crontab for current user to add/change/remove entries
#		and re-initialise "cron", it works for both AIX and Linux
#
# FLAGS:	-a	Add / Change cron entries to root's crontab
#		-d	Removes cron entries from root's crontab
#
# DEPENDENCIES:	None
#
# CHANGE HISTORY:
#
# Date		Author	Vers.  	Description
# -----------------------------------------------------------------------------
# 1996-12-30	JDW	1.0	Original
# 2013-06-06	xCAT	1.1	Updated version to ship with xCAT

usage()
{
	cat << EOF
Usage: $PROGNAME <-a | -d> <cron file>

EOF
}

##############################################################################

AddCron()
{

crontab -l | awk -v "CronFile=$1" \
	'BEGIN { FoundCronEntries="False" ;
	         StartString=sprintf ("### START: Added by cronEdit from file: %s", CronFile) ;
		 EndString=sprintf ("### END: Added by cronEdit from file: %s", CronFile)
}
{
	# Reading existing roots crontab

	if ( match ($0, StartString) > 0)
	{
		FoundCronEntries="True"
		continue
	}

	if ( match ($0, EndString) > 0)
	{
		FoundCronEntries="False"
		continue
	}

	if ( FoundCronEntries == "False")
	{
		print $0
	}
}
END {
	printf ("%s\n", StartString)
	SystemString = sprintf ("cat %s", CronFile)
	system (SystemString)
	printf ("%s\n", EndString)

}' > $CRONTEMP

}

##############################################################################

DeleteCron()
{

crontab -l | awk -v "CronFile=$1" \
	'BEGIN { FoundCronEntries="False" ;
	         StartString=sprintf ("### START: Added by cronEdit from file: %s", CronFile) ;
		 EndString=sprintf ("### END: Added by cronEdit from file: %s", CronFile)
}
{
	# Reading existing roots crontab

	if ( match ($0, StartString) > 0)
	{
		FoundCronEntries="True"
		continue
	}

	if ( match ($0, EndString) > 0)
	{
		FoundCronEntries="False"
		continue
	}

	if ( FoundCronEntries == "False")
	{
		print $0
	}
}' > $CRONTEMP

}

##############################################################################

PROGNAME=`basename $0`
CRONTEMP="/tmp/cron.tmp$$"
# AIX
if [ -e "/var/spool/cron/crontabs/$USER" ]
then
	CRONROOT="/var/spool/cron/crontabs/$USER"
else
	CRONROOT="/var/spool/cron"
fi

if [ $# -ne 2 ]
then
	usage 
	exit 1
fi

while getopts ':a:d:' opt
do
	case "$opt" in
		a)	AddCron "$OPTARG"
			;;
		d)	DeleteCron "$OPTARG"
			;;
		*)	usage
			exit 2
			;;
	esac
done

# Now respawn cron if necessary......

crontab -l | diff - $CRONTEMP 2>&1 > /dev/null

if [ $? -ne 0 ]
then
	# Changes are required......
	if [ `uname` = "AIX" ]
	then
		cp $CRONTEMP $CRONROOT
		CRONPID=`ps -ef | grep "/usr/sbin/cron" | grep -v grep | awk '{ print $2 }'`
		kill $CRONPID
	else # Linux: common user could not read/write /var/spool/cron
		crontab $CRONTEMP
	fi
fi

exit 0