代码: 全选
a='123'
if [ -z $a ];then echo '1' ;else echo '2';fi
if [ -n $a ];then echo '1' ;else echo '2';fi
可是当a为空字符串时
代码: 全选
a=''
if [ -z $a ];then echo '1' ;else echo '2';fi
if [ -n $a ];then echo '1' ;else echo '2';fi
代码: 全选
a=''
if [ -z "$a" ];then echo '1' ;else echo '2';fi
if [ -n "$a" ];then echo '1' ;else echo '2';fi