linux 字符串相关操作

Linux字符串

子串查询

• 从某个位置开始提取（下标从0开始）

[root@localhost update]# string="hello world"
[root@localhost update]# echo ${string:1}
ello world
[root@localhost update]#

• 从指定位置提取指定长度的子串

[root@localhost update]#  string="hello world"
[root@localhost update]#
[root@localhost update]# echo ${string:1:2}
el

子串匹配删除

• 从左非贪婪匹配删除

[root@localhost update]# string="hello world, hello jim"
[root@localhost update]# echo ${string#*hello}
world, hello jim

• 从左贪婪匹配删除

[root@localhost update]# string="hello world, hello jim"
[root@localhost update]# echo ${string##*hello}
jim
[root@localhost update]# string="hello world, hello*jim"
[root@localhost update]# echo ${string##*hello}
*jim
[root@localhost update]# string="hello world, hello *jim"
[root@localhost update]# echo ${string##*hello}
*jim

• 从右非贪婪匹配删除

[root@localhost update]# string="hello world, hello jim"
[root@localhost update]# echo ${string%hello*}
hello world,

• 从右贪婪匹配删除

[root@localhost ~]# string="#hello world, hello jim"
[root@localhost ~]# echo ${string%%hello*}
#
[root@localhost ~]#

子串替换

• 替换出现的第一次

[root@localhost ~]# string="hello world, hello jim"
[root@localhost ~]#
[root@localhost ~]# echo ${string/hello/goodbye}
goodbye world, hello jim

• 替换出现的所有子串

[root@localhost ~]# string="hello world, hello jim"
[root@localhost ~]#
[root@localhost ~]# echo ${string//hello/goodbye}
goodbye world, goodbye jim

参考：
​​​参考博文1​​