Rename files with non-Latin characters

Off the top of my head, Perl's Text::Unidecode module can do this (technically it will attempt to transliterate Unicode characters outside of ASCII's range into a suitable ASCII replacement):

The representation is almost always an attempt at transliteration-- i.e., conveying, in Roman letters, the pronunciation expressed by the text in some other writing system.

sudo apt install libtext-unidecode-perl

Most conveniently, you could combine this with the Perl-based rename utility and do the following:

rename -u utf8 -n 'BEGIN {use Text::Unidecode}; unidecode($_)' *

This will perform a dry-run (no filename will be changed but the result of the substitution for each file will be displayed); if you're happy with the result, remove the -n flag:

rename -u utf8 'BEGIN {use Text::Unidecode}; unidecode($_)' *

The -u option is important as it will tell rename / Perl to treat filenames as UTF-8-encoded strings.

% ls -la
totale 36
drwxrwxr-x  2 user user 32768 ott 15 19:53 .
drwxr-xr-x 42 user user  4096 ott 15 20:01 ..
-rw-rw-r--  1 user user     0 ott 15 19:53 Andúril
-rw-rw-r--  1 user user     0 ott 15 19:53 Dúnedain
-rw-rw-r--  1 user user     0 ott 15 19:53 Éomer
% rename -u utf8 'BEGIN {use Text::Unidecode}; unidecode($_)' *
% ls -la
totale 36
drwxrwxr-x  2 user user 32768 ott 15 20:01 .
drwxr-xr-x 42 user user  4096 ott 15 20:01 ..
-rw-rw-r--  1 user user     0 ott 15 19:53 Anduril
-rw-rw-r--  1 user user     0 ott 15 19:53 Dunedain
-rw-rw-r--  1 user user     0 ott 15 19:53 Eomer

My usual go-to for this type of things is a program called detox. It’s packaged on Ubuntu (and most other Linux distros) in a package of the same name.

The default behavior of the command will not actually entirely do what you want, as the primary purpose of the command is to get rid of shell metacharacters in file names, and the current version has shifted away from collapsing things down to ASCII since that is by definition lossy and modern filesystems have no issues with UTF-8 filenames.

However, on Debian, Ubuntu, and many other distros, it still includes the old translation tables that do essentially exactly what you want. In particular:

detox -r -s utf_8-only .

Will do exactly what you’re asking for, recursively for the current working directory. Dropping the -only on the third argument will make it also transform characters that would be interpreted by the shell (and thus normally need escaped on the command line) into safe equivalents (usually _).