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

On Tue, Sep 12, 2023 at 06:39:32PM +0200, Andreas Metzler <[email protected]> wrote:

> On 2023-09-12 Peng Yu <[email protected]> wrote:
> > Hi,
> 
> > How to find directories that only contain a certain type of files (e.g., .txt)?
> 
> > One idea that I have is to just search for all files' paths. Then use
> > a post-processing script to analyze which directories only contain
> > files of a certain type (e.g., .txt extension).
> 
> > Does anybody have a better idea of how to do this search?
> 
> find -name '*.txt' -printf '%h\n' | sort -u
> 
> (Actually you should use \0 and sort -u --zero-terminated and work on
> that nul-terminated list.)
> 
> cu Andreas

That will list directories that contain .txt files,
not directories that *only* contain .txt files.

This should do it (assuming filenames without newlines):

  find . -type d -exec sh -c '[ "$(find {} -mindepth 1 -maxdepth 1 | wc -l)" = "$(find {} -mindepth 1 -maxdepth 1 -type f -name "*.txt" | wc -l)" ]' \; -print

It lists directories that contain only *.txt files (i.e. no other
files and no subdirectories). If it needs to ignore subdirectories
and only exclude non-.txt files:

  find . -type d -exec sh -c '[ "$(find {} -mindepth 1 -maxdepth 1 -type f | wc -l)" = "$(find {} -mindepth 1 -maxdepth 1 -type f -name "*.txt" | wc -l)" ]' \; -print

But even that's not complete. It'll report empty directories (because 0 == 0), so:

  find . -type d -exec sh -c \ '[ "$(find {} -mindepth 1 -maxdepth 1 -type f -name "*.txt" | wc -l)" -gt 0 ] && [ "$(find {} -mindepth 1 -maxdepth 1 -type f | wc -l)" = "$(find {} -mindepth 1 -maxdepth 1 -type f -name "*.txt" | wc -l)" ]' \; -print

cheers,
raf