How to replace a hash pattern inside file and directory names

Question

I've just backed up the notes I have in Notion, and they use hashcodes in the notes names to make them unique apparently.

For example, this is might be a note-folder with some notes:

Archive e74f698cb73b42c790d08999bdbe47e4
├── Note 1 cda63bef095a493f9847d516cf34fa5f.md
├── Note 2 dda63bef095a493f9847d516cf34fa5f.md

(Sometimes there's also a .csv file for tables)

I was trying to use a regex like [a-z0-9]{32} to replace the pattern, but was having difficulty making it work with s/:

find -type f -print0 | xargs -0 rename 's/[a-z0-9]{32}//g'

(I'm not sure I really understand what the purpose of -print0 and -0 is.)

The code above only works for files, but I've also tried to use something like mv $f ${f:0:-34} though I couldn't make it work either. Is there a way of making this replacing with only one line for both files and folders, without fors?

I've tried many other answers on StackOverflow about this but almost all I've found so far either only deal with files or with fixed words as patterns.

I wanted to use the Mass-Move command line tool (mmv), but there's no official distribution for Arch Linux?

Answer 1

Note: the following assumes that you are using the Perl-based rename command, as implied by your observation that rename 's/[a-z0-9]{32}//g' "works for files". See

• What's with all the renames: prename, rename, file-rename?

---

To find directories as well as files, you need to remove the -type f restriction.

In addition you will need to prevent directories from being renamed before their containing files - with GNU find, that may be done using -depth to specify depth-first traversal.

Finally, you need to make sure that the rename command operate only on the file basename rather than its path components - your rename implementation may provide an option to do that (ex. -d, --filename, --nopath, --nofullpath) but you can also invoke rename directly from find using the -execdir action.

So

find . -depth -execdir rename -n 's/ [a-z0-9]{32}//' {} +

(remove the -n once you are satisfied with the proposed substitutions). Note that you don't need the g replacement flag to replace a single instance of the pattern per file.

You could also consider replacing [a-z0-9] with [[:xdigit:]].

See also:

• Understanding the -exec option of find
• find -exec + vs find | xargs: which one to choose?