shell脚本去除前后空格

1.trim脚本源码

#!/bin/bash

string=$1

if [[ "$1" == "" ]]
then
        string=`cat /dev/stdin | head -n 1`
fi

echo ${string%%[\s]*##[\s]*}

2.测试运行

$ ./trim " hello world "
hello world
$ echo " hello world " | ./trim
hello world