Change filename from lowercase to uppercase recursively

Question

I have 1,000,000 files in some folders and subfolders. I want to rename them from lowercase to uppercase using shell commands. I don't want to modify the extension. only filename part.

I have found this one:

rename 's/^([^.]*)\.(.*)$/\U$1\E.$2/' *

but it is not recursive and only works on files in current folder.

Then I tried this one:

find . -depth  -execdir rename 's/^([^.]*)\.(.*)$/\U$1\E.$2/' {} \;

But no files changed.

How can I use it recursively?

Solution

Assuming that you have the Perl rename provided by Debian and derived distributions such as Debian and Ubuntu, you're almost there. The problem is that -execdir passes a file name prefixed with ./ to the command. (The reason for that is that some commands treat arguments starting with some characters specially; this way, if you have a file called -foo, it's passed as ./-foo and therefore treated as a file and not as an option.) With your regex, this results in $1 being always empty, and hence the new name is identical to the old name.

Accommodate for this ./ in your regular expression.

find . -depth  -execdir rename 's/^(\.\/[^.]*)\.(.*)$/\U$1\E.$2/' {} \;

Comments

[manatwork]

And your shell is…? See your shell's manual to find out whether it supports ** syntax in globbing. bash (with globstar turned on) and zsh does.

[Admin]

If possible, you should backup your files before running anything.

[Gilles 'SO- stop being evil']

See also Renaming files to have lower case extensions with 'rename' and Lowercasing all directories under a directory for other methods of changing the case of file names.

[msw]

This is close to correct but it will fail on filenames with spaces or punctuation in them. It would also be a better answer if you explained why you are using -type.

[frostschutz]

never use ls for anything

[manatwork]

And how will that traverse the directory structure recursively, as requested in the question?

[Luis]

@manatwork: This new script takes into consideration the subdir part of the question that I overlooked before.

[manatwork]

Wondering who upvoted a ls call with --reverse instead of --recursive?

[manatwork]

Ok, it works fine now. But why you use fn=`echo "${bn%.*}"` instead of fn="${bn%.*}"?

[Gilles 'SO- stop being evil']

@msw What problem do you see with file names with whitespace? This will, however, fail on files in subdirectories that contain lowercase letters, as it will attempt to rename e.g. foo/bar.ext to FOO/BAR.ext (hd. used -execdir to work around this problem).

[Priya]

The above command fails on directory name with a dot(.) separator. ex : dir.xyz/abc.txt is being renamed to DIR.xyz/ABC.txt

[Priya]

@Gilles , there is no fail with directory as -type f only gives the file path. and renames $1 & $2 only touches the files inside the dir.

[msw]

It is ambiguous in the OP whether files or {files and directories} were to be changed. I read -type f and Giles infers the opposite. We're both wrong and both right.

[Gilles 'SO- stop being evil']

@Ameer rename will never be called with an argument of the form dir.xyz/abc.txt, because -execdir was used and not -exec. All the arguments to rename will be of the form ./SOMETHING where SOMETHING doesn't contain any slash. So dir.xyz will be renamed to DIR.xyz, which is consistent with the expressed requirements. Thanks to -depth, this happens after dir.xyz/abc.txt has been renamed to dir.xyz/ABC.txt, so there won't be a problem with find attempting to move into a directory that's been renamed without it knowing.