github.com/captn3m0/RT-AX53U.git

#!/bin/sh
D="/var/spool/cron/crontabs"
U="$D/cron.update"
F="$D/`nvram get http_username`"
N="$F.new"
L="/var/lock/cron.lock"

if [ $# -gt 1 -a "$1" = "a" -o "$1" = "d" ]; then
	if [ -f $L ];
	then
		I=$((($$ % 25) + 5))
		while ! rm $L 2>/dev/null; do
			I=$(($I - 1))
			[ $I -lt 0 ] && break
			sleep 1
		done
	fi

	ID=$2
	grep -v "#$ID#\$" $F >$N 2>/dev/null
	if [ "$1" = "a" ]; then
		shift
		shift
		echo "$* #$ID#" >>$N
	fi
	mv $N $F
	echo `nvram get http_username` >>$U
	
	echo >$L
	exit 0
fi

if [ "$1" = "l" ]; then
	cat $F 2>/dev/null
	exit 0
fi

cat <<END

Cron Utility
add:    cru a <unique id> <"min hour day month week command">
delete: cru d <unique id>
list:   cru l

END
exit 0