bash - 从 Bash 中的字符串中删除固定前缀/后缀

Question

我想从字符串中删除前缀/后缀。例如，给定:

string="hello-world"
prefix="hell"
suffix="ld"

如何得到下面的结果？

"o-wor"

Answer 1

$ prefix="hell"
$ suffix="ld"
$ string="hello-world"
$ foo=${string#"$prefix"}
$ foo=${foo%"$suffix"}
$ echo "${foo}"
o-wor

这记录在 Shell Parameter Expansion 中手册部分:

${parameter#word}
${parameter##word}

The word is expanded to produce a pattern and matched according to the rules described below (see Pattern Matching). If the pattern matches the beginning of the expanded value of parameter, then the result of the expansion is the expanded value of parameter with the shortest matching pattern (the # case) or the longest matching pattern (the ## case) deleted. […]

${parameter%word}
${parameter%%word}

The word is expanded to produce a pattern and matched according to the rules described below (see Pattern Matching). If the pattern matches a trailing portion of the expanded value of parameter, then the result of the expansion is the value of parameter with the shortest matching pattern (the % case) or the longest matching pattern (the %% case) deleted. […]