How to remove invalid characters from filenames?

Question

I have files with invalid characters like these

009_-_�%86ndringshåndtering.html

It is a Æ where something have gone wrong in the filename.

Is there a way to just remove all invalid characters?

or could tr be used somehow?

echo "009_-_�%86ndringshåndtering.html" | tr ???

Answer 1

One way would be with sed:

mv 'file' $(echo 'file' | sed -e 's/[^A-Za-z0-9._-]/_/g')

Replace file with your filename, of course. This will replace anything that isn't a letter, number, period, underscore, or dash with an underscore. You can add or remove characters to keep as you like, and/or change the replacement character to anything else, or nothing at all.

Answer 2

I assume you mean you want to traverse the filesystem and fix all such files?

Here's the way I'd do it

find /path/to/files -type f -print0 | \
perl -n0e '$new = $_; if($new =~ s/[^[:ascii:]]/_/g) {
  print("Renaming $_ to $new\n"); rename($_, $new);
}'

That would find all files with non-ascii characters and replace those characters with underscores (_). Use caution though, if a file with the new name already exists, it'll overwrite it. The script can be modified to check for such a case, but I didnt put that in to keep it simple.