Bash - For loop , exclude files with specific pattern in filename right before filetype

Question

I am trying to run a for loop but trying to exclude files with a specific pattern in the filename. This is the command I am using:

for file in /home/ubuntu/discovery/download/*![.en].mp4; do

I would like this filename to be included:

Blub - S03E10 - Nervous Breakdown.mp4

but this filename to be excluded

Blub - S03E10 - Nervous Breakdown.en.mp4

Can't get it to work. What am I doing wrong?

Thanks in advance

I would suggest you use `find` to generate a list of desired files (sans exclusions) and then feed this list to a `while/read` loop, eg, `while read -r fname; do do_some_stuff_with_fname; done < <(find /home/unbuntu/discovery/download ... exclude_some_file_types ...)` — markp-fuso, Mar 30 '23 at 18:33
@markp-fuso Syntaxe of questioni is close than correct! See [my answer](https://stackoverflow.com/a/75891852/1765658)! — F. Hauri - Give Up GitHub, Mar 30 '23 at 18:48

score 2 · Answer 1 · answered Mar 30 '23 at 18:37

What am I doing wrong?

Standard globbing has no grouping or group negation operators (though the extended version has these). In your particular context, I would just filter out the unwanted files inside the loop:

for file in /home/ubuntu/discovery/download/*.mp4; do
  case $file in
    *.en.mp4) continue;;
  esac

  # ...
done

And that should work in any Bourne-family shell, not just Bash.

F. Hauri - Give Up GitHub · Answer 2 · 2023-03-30T18:45:47.293

1

Pathname Expansion: "match not", with `extglob` enabled:

         !(pattern-list)
                Matches anything except one of the given patterns

Try this:

for file in /home/ubuntu/discovery/download/!(*.en).mp4; do
    ...

edited Mar 30 '23 at 18:45

answered Mar 30 '23 at 18:38

F. Hauri - Give Up GitHub

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If there are no files matching the glob pattern, `file` will be set to the glob pattern. Either verify that the path in `file` exists or enable `nullglob` with `shopt -s nullglob`. – Sanford Freedman Mar 30 '23 at 19:09
Correct., but this is same behaviour than `/path/*`! You coud test by using `[ -$àfile ]`... – F. Hauri - Give Up GitHub Mar 31 '23 at 05:37
One question: why does `!(*.en).mp4` work, but not `*!(.en).mp4` ? – Philippe Mar 31 '23 at 07:00
@Philippe because ***pattern*** have to begin by `!`. Aka `!(...)` is correct, `*!( ...)` is an unknown pattern. See [Remove all files except some from a directory](https://stackoverflow.com/a/15232634/1765658) – F. Hauri - Give Up GitHub Apr 07 '23 at 07:36

score 1 · Accepted Answer · answered Mar 30 '23 at 18:54

1

Another alternative could be:

shopt -s nullglob
for file in /home/ubuntu/discovery/download/*{[^n],[^e]n,[^.]en}.mp4
do
# ...
done

answered Mar 30 '23 at 18:54

M. Nejat Aydin

9,597
1
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score 0 · Answer 4 · answered Mar 30 '23 at 18:48

Another approach is to iterate over all files, skipping any that have undesirable name patterns. Just make sure to also handle the case where no files are found, because in that case, file is set equal to the glob pattern. Often you can handle that situation by verifying that the path in file actually exists (-e "${file}").

for file in /home/ubuntu/discovery/download/*.mp4; do
    [[ -e "${file}" && "${file}" != *.en.mp4 ]] || continue
    echo ${file}
done

Bash - For loop , exclude files with specific pattern in filename right before filetype

4 Answers4

Pathname Expansion: "match not", with extglob enabled:

Pathname Expansion: "match not", with `extglob` enabled: