Bash Shell字符串操作

╰+攻爆jí腚メ 2022-05-13 16:00 242阅读 0赞

Bash字符串处理

> var=“hello\_world\_icbc\_cib”

*  获取长度

> $\{\#string\}

echo ${#var}

*  字符串截取

> $\{string:position\}

> $\{string:position:length\}

#
    echo ${var:0:2}
    #
    echo ${var:2}
    #
    echo ${var:0-4:3}
    #
    echo ${var:0-4}

*  最短字串匹配

> $\{string\#substring\}，从左到右，删除匹配子串substring的最短字符，保留右侧字符。

> $\{string%substring\}，从右到左，删除匹配字串substring的最短字符，保留左侧字符

#
    echo ${var#*_}
    #
    echo ${var%_*}

*  最长字串匹配

> $\{string\#\#substring\}，从左到右，删除匹配子串substring的最长字符，保留右侧字符。

> $\{string%%substring\}，从右到左，删除匹配字串substring的最长字符，保留左侧字符

#
    echo ${var##*_}
    #
    echo ${var%%_*}

*  字符替换

> $\{string/pattern/replacement\}，只替换第一个匹配的字符

> $\{string//pattern/replacement\}，替换所有匹配字符

#
    echo ${var/ic*_/ccb_}
    #
    echo ${var/i/I}
    #
    echo ${var//i/I}

*  替换开始和结束

> $\{string/\#pattern/replacement\}，只有当字串string以pattern开头，才执行对应替换。

> $\{string/%pattern/replacement\}，只有当字串string以pattern结尾，才执行对应替换。

filename="/home/test/str.sh"
    echo "replace at the beginning: "${filename/#\/home/\/begin}
    echo "replace at the ending: "${filename/%.*/.txt}

**代码段**

#!/bin/bash
    
    var="hello_world_icbc_cib"
    #
    echo ${#var}
    #
    echo ${var#*_}
    #
    echo ${var##*_}
    #
    echo ${var%_*}
    #
    echo ${var%%_*}
    #
    echo ${var:0:2}
    #
    echo ${var:2}
    #
    echo ${var:0-4:3}
    #
    echo ${var:0-4}
    #
    echo ${var/ic*_/ccb_}
    #
    echo ${var/i/I}
    #
    echo ${var//i/I}
    
    #
    filename="/home/test/str.sh"
    echo "replace at the beginning: "${filename/#\/home/\/begin}
    echo "replace at the ending: "${filename/%.*/.txt}
    
    echo "bye..."

*执行结果*

![在这里插入图片描述][70]

[https://www.thegeekstuff.com/2010/07/bash-string-manipulation/][https_www.thegeekstuff.com_2010_07_bash-string-manipulation]

[70]: /images/20220504/4d797ec66bef498c8dc4db58a4ae150b.png
[https_www.thegeekstuff.com_2010_07_bash-string-manipulation]: https://www.thegeekstuff.com/2010/07/bash-string-manipulation/