bash 是否使用正则表达式搜索？

Question

bash 是否使用正则表达式搜索？

例如，如果我想做一个 for 循环遍历当前目录中以字母 a 开头的所有文件，下面的方法是否可行？

for x in a.*
do

Answer 1

当谈到 文件名扩展 时，ABS 指出：

Bash itself cannot recognize Regular Expressions.
Inside scripts, it is commands and utilities -- such as sed and awk -- that interpret RE's.

Bash does carry out filename expansion -- a process known as globbing, but this does not use the standard RE set. Instead, globbing recognizes and expands wild cards.

More on wildcards.

然而，正如 chepner, bash DOES support regex 在 filename expansion 上下文之外提到的：

(digit=5; [[ $digit =~ [0-9] ]] && echo match)

回到 OP 的问题，遍历以 a:

开头的所有文件

for x in a* ; do
    [[ -f "$x" ]] || continue
    # process x
done

bash 是否使用正则表达式搜索？

Does bash search with regex?

regex

syntax

bash

shell

sh