Regex to find files with certain number of underscores

Question

I have two files:

AAAAA_AAAA_BBBBBBBB_SSSSSS
AAAAA_BBBBBBBB_SSSSSS

I want only the file with two underscores be shown.

I used:

ls -1 ^?*_?*_?*$

I got:

ls: ?*_?*_?*$: No such file or directory

Why? And what can be a solution?

score 2 · Accepted Answer · answered Jan 11 '18 at 05:51

2

You've mixed up shell globs and regular expression syntax - and come up with something that's not valid in either.

If you want to use a regex based tool, try find e.g.

find . -maxdepth 1 -regex '^[^_]*_[^_]*_[^_]*$'

answered Jan 11 '18 at 05:51

steeldriver

Thanks. ls | grep '^[^_][^][^]*$' also works. Why just ls cannot take regex? – Josef Klimuk Jan 11 '18 at 05:56
2

@JosefKlimuk the ls command itself doesn't interpret the pattern - that's done by the shell (and it uses a much simpler glob syntax ) – steeldriver Jan 11 '18 at 06:01

1 Answers1