Bash Shell字符串操作

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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

https://www.thegeekstuff.com/2010/07/bash-string-manipulation/