How do I find all files that do not begin with a given prefix in bash?

Question

I have a bunch of files in a folder:

foo_1 
foo_2
foo_3
bar_1
bar_2
buzz_1
...

I want to find all the files that do not start with a given prefix and save the list to a text file. Here is an example for the files that do have a given prefix:

find bar_* > Positives.txt

Duplicate http://stackoverflow.com/questions/216995/how-can-i-use-inverse-or-negative-wildcards-when-pattern-matching-in-a-unix-linu — Reinstate Monica Please, Jan 26 '14 at 20:41
@BroSlow Yes that question is similar but I would argue that this is more discoverable. I did not think to search for the terms in that question. — Robert, Jan 26 '14 at 21:00

lurker · Answer 1 · 2020-06-23T18:10:04.167

9

If you're doing subdirectories as well:

find . ! -name "bar_*"

Or, equivalently,

find . -not -name "*bar_*"

edited Jun 23 '20 at 18:10

answered Jan 26 '14 at 20:40

lurker

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don't forget to escape the `!` on the shell prompt – zmo Jan 26 '14 at 20:43
Curious to see a situation where we really need to escape `!`, have never experienced it. – grebneke Jan 26 '14 at 20:45
@grebneke The `!` needs to be escaped when it's mixed with some characters together as one word. – kenorb Jul 21 '16 at 00:27
1

Btw. Instead of `!`, `-not` can be used. – kenorb Jul 21 '16 at 00:27
@kenorb Fine, so basically we agree that a single `!` never needs to be escaped in everyday scripting. – grebneke Aug 09 '16 at 14:44

score 7 · Accepted Answer · answered Jan 26 '14 at 20:39

7

This should do the trick in any shell

ls | grep -v '^prefix'

The -v option inverts grep's search logic, making it filter out all matches. Using grep instead of find you can use powerful regular expressions instead of the limited glob patterns.

answered Jan 26 '14 at 20:39

Jens

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Gnu find implements the `-regex` test for "powerful" regular expressions. – rici Jan 26 '14 at 20:44
As stated, it inverts the output logic: instead of outputting matching lines, it outputs non-matching lines. – Jens Jan 26 '14 at 20:44
ah yes - sorry missed that. – Robert Jan 26 '14 at 20:45
@rici Right, but it is best practice in shell programming to avoid GNUisms. In my career they invariably cause portability problems. If I can, I strive to write POSIX compliant scripts. – Jens Jan 26 '14 at 20:48

score 5 · Answer 3 · answered Jan 26 '14 at 20:41

5

You want to find filenames not starting with bar_*?

recursive:

find ! -name 'bar_*' > Negatives.txt

top directory:

find -maxdepth 1 ! -name 'bar_*' > Negatives.txt

answered Jan 26 '14 at 20:41

grebneke

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But that's recursive. – EverythingRightPlace Jan 26 '14 at 20:41
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don't forget to escape the `!` on the shell prompt – zmo Jan 26 '14 at 20:42
1

@zmo - Yes I know *man find* says `!` might need to be escaped, but I have never encountered an occasion when that is true. Do you have an example of shell or situation when `\!` really is necessary? – grebneke Jan 26 '14 at 20:43
It's passed as an argument regardless of escaping. – Reinstate Monica Please Jan 26 '14 at 20:46
@BroSlow - I don't understand what that implies? You're saying we should escape ! or not? – grebneke Jan 26 '14 at 20:49
it actually depends on how your shell is configured… and if you put quotes around the `"!"` you may have surprises. Usually `!` is for history related stuff… though I'm not sure a lone `!` will actually do something. – zmo Jan 26 '14 at 20:50
@zmo - Do you have an example of a shell configuration where escaping the naked `!` is required? – grebneke Jan 26 '14 at 20:52
well, not with my shells zsh/bash :-) – zmo Jan 26 '14 at 20:55

score 0 · Answer 4 · edited Jan 31 '18 at 06:12

0

Using bash and wildcards: ls [!bar_]*. There is a caveat: the order of the letters is not important, so rab_something.txt will not be listed.

edited Jan 31 '18 at 06:12

Benjamin W.

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answered Oct 03 '16 at 19:04

Etienne

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Since you're using Bash, you might as well use extended globs here: `printf '%s\n' !(bar_*) > Positives.txt`. Don't forget to turn extended globs on with `shopt -s extglob` if you use this in scripts. – gniourf_gniourf Oct 03 '16 at 19:15

score 0 · Answer 5 · answered Jan 31 '18 at 06:12

0

With extended globs:

shopt -s extglob
ls !(bar_*) > filelist.txt

The !(pattern) matches anything but pattern, so !(bar_*) is any filename that does not start with bar_.

answered Jan 31 '18 at 06:12

Benjamin W.

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score 0 · Answer 6 · answered Aug 13 '19 at 10:38

In my case I had an extra requirement, the files must end with the .py extension. So I use:

find . -name "*.py" | grep -v prefix_

In your case, to just exclude files with prefix_:

find . | grep -v prefix_

Note that this includes all sub-directories. There are many ways to do this, but it can be easy to remember for those already familiar with find and grep -v which excludes results.

How do I find all files that do not begin with a given prefix in bash?

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