UNIX for Dummies Questions & Answers

#!/bin/bash
# OSX 10.7.5, default bash terminal.
# sunday.sh
# As /tmp/number does not exist then this will create an error on the very first run. This is OK.
read n < /tmp/number
#
if [ "$n" == "" ]
then
	n=1
	printf "$n" > /tmp/number
fi
DATE=`date`
if [ "${DATE:0:3}" == "Sun" ]
then
	echo "Do lots of tasks here!"
else
	echo "It is not Sunday, so nothing to do!"
	exit 1
fi
n=$[ ( $n + 1 ) ]
printf "$n" > /tmp/number
if [ $n -gt 3 ]
then
	n=1
	printf "$n" > /tmp/number
	echo "Counter reset to 1 and email sent..."
	# Do your email send here...
	exit 2
fi
exit 0

Last login: Sun Jun 22 18:12:33 on ttys000
AMIGA:barrywalker~> rm /tmp/number
AMIGA:barrywalker~> ./sunday.sh
./sunday.sh: line 5: /tmp/number: No such file or directory
Do lots of tasks here!
AMIGA:barrywalker~> ./sunday.sh
Do lots of tasks here!
AMIGA:barrywalker~> ./sunday.sh
Do lots of tasks here!
Counter reset to 1 and email sent...
AMIGA:barrywalker~> _

if condition1 ; then
     exit 1
fi

if condition2 ; then
     exit 2
fi

# main processing here

exit 0

if [ "${DATE:0:3}" == "Sun" ]
then
	echo "Do lots of tasks here!"
	exit 0
else
	echo "It is not Sunday, so nothing to do!"
	n=3
	printf "$n" > /tmp/number
	# exit 1
fi