shell比较两个整数大小并严格判断参数输入脚本

代码如下

#!/bin/sh
[ $# -ne 2 ] && {
   echo "USAGE: $0 agr1 arg2 "
   exit 1
}

expr $1 + 0 &>/dev/null
if [ $? -ne 0 ] ;then
   echo "$1 is not int"
   exit 1
fi

expr $2 + 0 &>/dev/null
if [ $? -ne 0 ] ;then
   echo "$2 is not int"
   exit
fi

if [ $1 -gt $2 ]
then 
   echo "$1 > $2"
elif [ $1 -eq $2 ]
 then 
   echo "$1 = $2"
else
   echo "$1 < $2"
fi
~      

访问方式：

[root1@bogon shelldir]$ sh campareInt.sh 1 9
1 < 9
[root1@bogon shelldir]$ sh campareInt.sh 4 3
4 > 3
[root1@bogon shelldir]$ sh campareInt.sh a 1
a is not int

判断一个字符串是否为数字的方法

expr $1 "+" 10 &> /dev/null
if [ $? -eq 0 ];then
  echo "$1 is number"
else
  echo "$1 not number"
fi