#! /bin/bash

# "Divide" a crontab frequency down by the first argument on the command line,
# logging to the second argument, and executing the remainder.

if [ -z "$1" ] || [ -z "$2" ] || [ -z "$3" ]; then
	echo "Usage: $0 frequency logfile command [ arguments ]" >&2
	exit 1
fi

FREQUENCY="$1"
LOGFILE="$2"
shift 2

if [ -f "$LOGFILE" ]; then
	LASTEXEC="$(($(tail -n 1 "$LOGFILE")+1))"
else
	LASTEXEC=1
fi

if [ "$LASTEXEC" -ge "$FREQUENCY" ]; then
	echo "$* executed at $(date)" >> "$LOGFILE"
	echo 0 >> "$LOGFILE"
	eval "$*"
else
	echo "$LASTEXEC" >> "$LOGFILE"
fi