wholenum

来自「Advanced Bash&#8722 Scripting Guide An 」· 代码 · 共 14 行

#!/bin/sh
# Name:wholenum
# Purpose:The expr command tests that the user enters an integer
#
echo "Enter a number."
read number
if expr "$number" + 0 > /dev/null 2>&1
then
    :
else
    echo "You did not enter an integer value."
    exit 1
fi