Re: What is wrong with a regex?

[Koichi Murase]

2023年2月4日(土) 12:44 Peng Yu <pengyu.ut@gmail.com>:
> $ f=row.txt; [[ $f =~ ^row([0-9]*)(\|_x)[.]txt$ ]]; echo $?
> 1

You need to write (|_x) instead of (\|_x). In the conditional command
[[ ... ]], the character `|' loses the original meaning of the pipe
operator, so you can directly specify it without quoting. If you quote
it as \|, it becomes a regular expression that matches a literal
single character `|'.

$ [[ '|' =~ \| ]]; echo $?
0