Linux “find -regex” doesn't handle binding

Question

I have the following files, and need to match them like:

./foo.bar1.sh       -match

./qux/foo.bar2.sh   -match

./foo.sh            -match

./baz.sh            -no match

./foo.bar3          -no match

I have tried:

find . -regex ".*foo(bar[0-9])?.sh"

but it returns nothing. I cannot figure out why that regex won't work... help please?

Dennis · Accepted Answer · 2012-05-31 05:22:03Z

Your regular expression has two errors:

It misses a (literal) dot after foo.
find requires you to escape the parentheses when not used as literal parentheses.

Also, you should escape the dot before sh, since it will match any character.

The fixed command now reads:

find . -regex ".*foo\(\.bar[0-9]\)?\.sh"

Error 2., by the way, is the reason why I don't like find's -regex switch: Inconsistent escaping.

It works, of course, but grep -P uses Perl Compatible Regular Expressions (PCRE), so there are more features, but less surprises and pitfalls.

Personally, I'd use:

find . | grep -P "foo(\.bar\d)?\.sh"

1 Answer