shell条件判断式语句下

一 字符串判断

 

 

二 实战

[root@localhost ~]# name=fengji

[root@localhost ~]# [ -z $name ] && echo yes || echo no

no

[root@localhost ~]# name=""

[root@localhost ~]# [ -z $name ] && echo yes || echo no

yes

[root@localhost ~]# aa=11

[root@localhost ~]# bb=22

[root@localhost ~]# [ "$aa" == "$bb" ] && echo yes || echo no

no

[root@localhost ~]# [ "$aa" -eq "$bb" ] && echo yes || echo no

no

[root@localhost ~]# aa=22

[root@localhost ~]# [ "$aa" -eq "$bb" ] && echo yes || echo no

yes

[root@localhost ~]# [ "$aa" == "$bb" ] && echo yes || echo no

yes

 

三 多重条件判断

 

 

四 实战

[root@localhost ~]# aa=22

[root@localhost ~]# [ -n "$aa" -a "$aa" -gt 33 ] && echo yes || echo no

no

[root@localhost ~]# [ -n "$aa" -a "$aa" -gt 3 ] && echo yes || echo no

yes