bash字符串截取方式

 

在处理 Bash 变量、文件路径、参数解析 时非常实用。

语法	作用	示例	结果
${var#prefix}	删除左侧最短匹配	"hello-world" → ${var#*-}	"world"
${var##prefix}	删除左侧最长匹配	"hello-world-example" → ${var##*-}	"example"
${var%suffix}	删除右侧最短匹配	"hello-world-example" → ${var%-*}	"hello-world"
${var%%suffix}	删除右侧最长匹配	"hello-world-example" → ${var%%-*}	"hello"
${var:offset}	从 offset 处截取	"hello-world" → ${var:6}	"world"
${var:offset:length}	从 offset 开始截取 length 个字符	"hello-world" → ${var:6:3}	"wor"
${#var}	获取字符串长度	"hello-world" → ${#var}	11
${var/pattern/replacement}	替换第一个匹配项	"hello world world" → ${var/world/planet}	"hello planet world"
${var//pattern/replacement}	替换所有匹配项	"hello world world" → ${var//world/planet}	"hello planet planet"