wholenum

Unix Shell编程权威指南的配套源代码,书是好书,不过习题没有答案,要自己做了

#!/bin/bash
# Scriptname: wholenum
# Purpose:The expr command tests that the user enters an 
# integer
#
echo "Enter an integer."
read number
if expr "$number" + 0 >& /dev/null 
then
	:
else
	echo "You did not enter an integer value."
	exit 1
fi