Finding Files Irrespective of Case in bash

Some of your MP3 files end with .MP3 rather than .mp3. How do you find those?

Use the -iname predicate (if your version of find supports it) to run a case-insensitive search, rather than just -name.

For example:

Sometimes you care about the case of the filename and sometimes you don’t.

Use the-iname option when you don’t care, in situations like this, where .mp3 or .MP3 both indicate that the file is probably an MP3 file.

(We say probably because on Unix-like systems you can name a file anything that you want.

It isn’t forced to have a particular extension.)
One of the most common places where you’ll see the upper- and lowercase issue is when dealing with Microsoft Windows-compatible filesystems, especially older or “lowest common denominator” filesystems.

A digital camera that we use stores its files with filenames like PICT001.JPG, incrementing the number with each picture.

If you were to try:

you wouldn’t find many pictures. In this case you could also try:

since that regular expression will match either letter in brackets, but that isn’t as easy to type, especially if the pattern that you want to match is much longer.

In practice, -iname is an easier choice. The catch is that not every version of find supports the -iname predicate.

If your system doesn’t support it, you could try tricky regular expressions as shown above, use multiple -name options with the case variations you expect, or install the GNU version of find.