find only files with extension using ls

Question

I need to find only files in directory which have a extension using ls (can't use find).

I tried ls *.*, but if dir doesn't contain any file with extension it returns "No such file or directory".

I dont want that error and want ls to return to cmd prompt if there are files with extension.

I have trying to use grep with ls to achieve the same.

ls|grep "*.*" - doesn't work but ls | grep "\." works.

I have no idea why grep *.* doesn't work. Any help is appreciated!

Thanks!

Yes, as mentioned above it works. Can you explain why it does and why \*.\* doesn't? — Android_enthusiast, Apr 08 '13 at 03:53
`ls *.{mp3,exe,mp4}` This question should help: http://stackoverflow.com/questions/1447625/list-files-with-certain-extensions-with-ls-and-grep — Joban, Apr 08 '13 at 03:53
ls is not the tool for the job. You need to use `find`. Whatever the constraint against `find` is, please let us know and we'll help you work around it. — Andy Lester, Apr 08 '13 at 04:25
@VaughnCato Except when the "regular expression" is also a glob pattern that is not quoted to protect it from expansion before `grep` even sees it... `grep *.*` is all sorts of fun waiting to happen... — twalberg, Mar 20 '14 at 19:56

score 2 · Answer 1 · answered Apr 08 '13 at 04:04

I think the correct solution is this:

( shopt -s nullglob ; echo *.* )

It's a bit verbose, but it will always work no matter what kind of funky filenames you have. (The problem with piping ls to grep is that typical systems allow really bizarre characters in filenames, including, for example, newlines.)

The shopt -s nullglob part enables ("sets") the nullglob shell optoption, which tells Bash that if no files have names matching *.*, then the *.* should be removed (i.e., should expand into nothing) rather than being left alone.

The parentheses (...) are to set up a subshell, so the nullglob option is only enabled for this small part of the script.

score 2 · Answer 2 · answered Mar 20 '14 at 19:25

2

Try

ls -1 | grep "\."

list only files with extensión and nothing (empty list) if there is no file: like you need.

With Linux grep, you can add -v to get a list files with no extension.

answered Mar 20 '14 at 19:25

0zkr PM

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Vaughn Cato · Answer 3 · 2013-04-08T04:04:25.663

It's important to understand the difference between a shell pattern and a regular expression. Shell patterns are a bit simpler, but less flexible. grep matches using a regular expression. A shell pattern like

*.*

would be done with a regular expression as

.*\..*

but the regular expressions in grep are not anchored, which means it searches for a match anywhere on the line, making the two .* parts unnecessary.

find only files with extension using ls

3 Answers3