Non consistent readings of "@eadir" directories by similar find commands

Question

A) This will output all the *.JPG and *.flac files recursively:

$ find . -type f -name "*.JPG" -o -name "*.flac"

Output includes: 1 JPG document and 254 flac documents

B) This will output only *.flac files recursively:

$ find . -type f -name "*.flac"

Output includes: 218 flac documents

I would assume all *.flac files listed with those two commands would match the exact same amount of files for each of those. The only difference would be that the first command would include *.JPG on top of all *.flac files, right? Not exactly. In case you are an iTunes user, you may be familiar with @eadir directories. Surprisingly, the first command will include even *.flac files within those @eadir directories (36 *.flac files), but the second command will not.

Why do those two commands return different results for the same file type?

Answer 1

find . -type f -name "*.JPG" -o -name "*.flac" looks for files that match at least one (-o) of the following conditions:

• regular files (-type f) whose name ends with .JPG (-name "*.JPG");
• files (of any type) whose name ends with .flac (-name "*.flac").

find . -type f -name "*.JPG" -o -name "*.flac" is equivalent to find . \( -type f -name "*.JPG" \) -o \( -name "*.flac" \). In more formal terms, juxtaposition (which means “and”) binds more tightly than the -o operator (which means “or”).

The @eadir directories apparently contain non-regular files, perhaps symbolic links. The .flac files that the first command returns but not the second one are not regular files. You can see what they are with the following command:

find . ! -type f -name "*.flac" -exec ls -ld {} +