CODEWITHSUNDEEP
bashshellfileshls
Yassine
Yassine

Reputation: 107

Is it possible to list files that match a pattern with ls?

I want to list files of a directory with ls that match a pattern without using grep. Is it possible?

The point is to retrieve all files that match this pattern '^\Extra_text_[0-9]\{10\}.csv' and count how much I got.

I tried this code:

ls | grep '^\Extra_text_[0-9]\{10\}.csv'

InputName=' | grep ^\Extra_text_[0-9]\{10\}.csv'

fileCount=`ls $INPUT_FILE/$InputName 2>/dev/null | wc -l`

echo "$fileCount

But it doesn't work! :/

Upvotes: 6

Views: 14779

Answers (2)

Lee Li
Lee Li

Reputation: 404

You may use file-matching metacharacters.

* matches any number of characters
? matches any one character
[...] matches any one of the characters between the brackets 
which can include a hyphen-separated range of letters or numbers

enter image description here Above just an example, maybe not exactly what you are trying to do. As I can't figure out what your regex means.

ls -l  Extra_text_[0-9]{10}.csv | wc -l

You may use the command above to count how many files you get.

Reference

Negus, C. (2020) Linux Bible, 10th Edition. Wiley

Upvotes: 2

Michael Jaros
Michael Jaros

Reputation: 4681

Not with ls only. ls does not know about patterns at all. It can only be used with globbing (wildcards * and ? or extended globbing - see extglob in the Bash manual page) offered by the shell, but not with regular expressions.

An easy way is to use find for this job (note that the regex needs to match the whole filename):

find . -regex '<yourpattern>'

To count results, pipe to wc:

# safe for corner case: version of find w/o newline escaping and files with newlines:
find . -regex '<yourpattern>' -printf '.' | wc -c    

# fallback for non-GNU platform, corner cases not addressed:
find . -regex '<yourpattern>' | wc -l

Find -regex in the find manual page for more information.

Upvotes: 4

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