Re: How to find directories that only contain a certain type of files (e.g., .txt)?

[Bernhard Voelker]

On 9/15/23 17:24, Peng Yu wrote:
> > > On 2023-09-12 Peng Yu <pengyu.ut@gmail.com> wrote:
> > > > How to find directories that only contain a certain type of files (e.g., .txt)?

> This is too inefficient. It will call sh too many times.
>
> To be efficient, I will have to call find to just get the path of all
> files and process the output with another text processing program like
> awk?

Some subtraction from a parallel fifo with `comm` should do:

$ mkdir test && cd test

$ mkdir -p some/empty_dir some/dir-with-mov-only some/dir-with-mov-and-other 
some/dir-with-mov-and-subdir/subdir

$ touch \
    some/dir-with-mov-only/f.mov \
    some/dir-with-mov-and-other/f.{mov,other} \
    some/dir-with-mov-and-subdir/f3.mov \
    some/dir-with-mov-and-subdir/subdir/f.mov

$ find
.
./some
./some/dir-with-mov-and-other
./some/dir-with-mov-and-other/f.other
./some/dir-with-mov-and-other/f.mov
./some/dir-with-mov-only
./some/dir-with-mov-only/f.mov
./some/dir-with-mov-and-subdir
./some/dir-with-mov-and-subdir/subdir
./some/dir-with-mov-and-subdir/subdir/f.mov
./some/dir-with-mov-and-subdir/f3.mov
./some/empty_dir


$ mkfifo fifo

$ find -type f -name '*.mov' -printf '%h\0' \
    | sort -zu \
    | tee fifo \
    | find -files0-from - -mindepth 1 -maxdepth 1 -not \( -type f -name '*.mov' 
\) -printf '%H\0' \
    | sort -zu \
    | comm -z23 fifo - \
    | xargs -0tn1 ls -laog
ls -laog ./some/dir-with-mov-and-subdir/subdir
total 8
drwxr-xr-x 2 4096 Sep 16 00:10 .
drwxr-xr-x 3 4096 Sep 16 00:10 ..
-rw-r--r-- 1    0 Sep 16 00:10 f.mov
ls -laog ./some/dir-with-mov-only
total 8
drwxr-xr-x 2 4096 Sep 16 00:10 .
drwxr-xr-x 6 4096 Sep 16 00:10 ..
-rw-r--r-- 1    0 Sep 16 00:10 f.mov

The part with the second 'find' outputs the names of the directories to 
subtract.
Isn't that what you want?

Have fun,
Berny