File Permissions – How to Recursively List Files with File Names, Folder Names, and Permissions

You can do the entire task using just find:

$ find . -type f ! \( -perm 755 -o -perm 644 \) -printf "%m\t%p\n"

Example

Make all permutations of permissions (000-777).

$ touch {0..7}{0..7}{0..7}
$ for i in {0..7}{0..7}{0..7}; do chmod $i $i;done
$ find . -type f | wc -l
512

A sample of our find command's list of files it's finding:

$ find . -type f ! \( -perm 755 -o -perm 644 \) -printf "%m\t%p\n"| head -10
734 ./734
376 ./376
555 ./555
663 ./663
256 ./256
336 ./336
2   ./002
152 ./152
527 ./527
416 ./416

If we run our find command we can confirm that it worked:

$ find . -type f ! \( -perm 755 -o -perm 644 \) -printf "%m\t%p\n" | grep 755
$ find . -type f ! \( -perm 755 -o -perm 644 \) -printf "%m\t%p\n" | grep 644

Your understanding is pretty much correct. A better way to think of the execute permission is that it allows you to do things with a file or directory name in the directory (other than just reading the name itself). Most of those things involve translating the name to an inode, but it also includes creating new names and removing existing names.

Write permission to the directory without execute is therefore pretty useless, since there's nothing you can actually write if you can't access the files within it.