Gfrktyl

I have a debian server and I'm hosting music for an internet radio station. I have trouble with file names and paths because a lot of files got an invalid encoding, for example:

./music/Bändname - Some Title - additional Info/B�ndname - 07 - This Title Is Cörtain, The EncÃding Not.mp3

Ideally, I would like to remove everything that is not letters A-Z/a-z or numbers 0-9 or dash -/underscore _... The result should look like something like that:

./music/Bndname-SomeTitle-additionalInfo/Bndname-07-ThisTitleIsCrtain,TheEncdingNot.mp3

How to achieve this for a batch of a lot of files and directories?

I've seen this similar question: bulk rename (or correctly display) files with special characters

But this only fixes the encoding, I would prefer a more strict approach as described above.

You're going to run in some problems if you want to rename files and directories at the same time. Renaming just a file is easy enough. But you want to make sure the directories are also renamed. You can't simply mv Motörhead/Encöding Motorhead/Encoding since Motorhead won't exist at the time of the call.

So, we need a depth-first traversal of all files and folders, and then rename the current file or folder only. The following works with GNU find and Bash 4.2.42 on my OS X.

#!/usr/bin/env bash

find "$1" -depth -print0 | while IFS= read -r -d '' file; do

  d="$( dirname "$file" )"

  f="$( basename "$file" )"

  new="${f//[^a-zA-Z0-9/._-]/}"

  if [ "$f" != "$new" ]      # if equal, name is already clean, so leave alone

  then

    if [ -e "$d/$new" ]

    then

      echo "Notice: "$new" and "$f" both exist in "$d":"

      ls -ld "$d/$new" "$d/$f"

    else

      echo mv "$file" "$d/$new"      # remove "echo" to actually rename things

    fi

  fi

done

You may change the regex by using new="${f//[\/:*?"<>|]/}" if you want to replace anything that Windows cannot handle.

Save this script as rename.sh, make it executable with chmod +x rename.sh. Then, call it like rename.sh /some/path.

Make sure to resolve any file name collisions (“Notice” announcements).

If you're absolutely sure it does the right replacements, remove the echo from the script to actually rename things instead of just printing what it does.

To be safe, I'd recommend testing this on a small subset of files first.

Options explained

To explain what goes on here:

• 
  -depth will ensure directories are recursed depth-first, so we can "roll up" everything from the end. Usually, find traverses differently (but not breadth-first).


• 
  -print0 ensures the find output is null-delimited, so we can read it with read -d '' into the file variable. Doing so helps us deal with all kinds of weird file names, including ones with spaces, and even newlines.


• We'll get the directory of the file with dirname. Don't forget to always quote your variables properly, otherwise any path with spaces or globbing characters would break this script.


• We'll get the actual filename (or directory name) with basename.


• Then, we remove any invalid character from $f using Bash's string replacement capabilities. Invalid means anything that's not a lower- or uppercase letter, a digit, a slash (/), a dot (.), an underscore, or a minus-hyphen.


• If $f is already clean (the cleaned name is identical to the current name), skip it.


• If $new already exists in directory $d (e.g., you have files named resume and résumé in the same directory), issue a warning. You don't want to rename it, because, on some systems, mv foo foo causes a problem.  Otherwise,


• We finally rename the original file (or directory) to its new name

Since this will only act on the deepest hierarchy, renaming Motörhead/Encöding to Motorhead/Encoding is done in two steps:

1. mv Motörhead/Encöding Motörhead/Encoding


2. mv Motörhead Motorhead

This ensures all replacements are done in the correct order.

Example files and test run

Let's assume some files in a base folder called test:

test

test/Motörhead

test/Motörhead/anöther_file.mp3

test/Motörhead/Encöding

test/Randöm

test/Täst

test/Täst/Töst

test/with space

test/with-hyphen.txt

test/work

test/work/resume

test/work/résumé

test/work/schedule

Here is the output from a run in debug mode (with the echo in front of the mv),
i.e., the commands that would be called, and the collision warnings:

mv test/Motörhead/anöther_file.mp3 test/Motörhead/another_file.mp3

mv test/Motörhead/Encöding test/Motörhead/Encoding

mv test/Motörhead test/Motorhead

mv test/Randöm test/Random

mv test/Täst/Töst test/Täst/Tost

mv test/Täst test/Tast

mv test/with space test/withspace

Notice: "resume" and "résumé" both exist in test/work:

-rw-r—r--  …  …  test/work/resume

-rw-r—r--  …  …  test/work/résumé

Notice the absence of messages for with-hyphen.txt, schedule, and test itself.

I know that it's not exactly what you wanted, but if you know the original encoding, perhaps you can use convmv to change the encoding to UTF-8, which should fix most problems.

This worked for me on a folder with some invalid-encoded Polish filenames:

convmv -f cp1250 -t utf8 -r .

Note that this command doesn't actually rename anything; add --notest option to really rename the files.

I know, you asked about renaming.

But you can dodge the problem quite easily using software like MusicBrainz Picard.

It is capable of identifying music (audio fingerprinting), downloading all the necessary data (including cover images, where available) from the huge MusicBrainz database and moving the files around so that your collection can fit any pattern you like. I'm using it for years and it always worked perfectly with anything from Cyrilic to Arabic; and of course (at least for Latin-based scripts) it can also do the conversion to ASCII.

With this approach it does not really matter how messy/badly named your collection really is, as long as the files are readable and complete.

(Did I mention it's free? Both as in free speech and as in free beer? Both the software and the database..?)