Careful: chmod -X also looks for any existing exec bits:
$ umask 0$ >foo >bar$ ls -al foo bar
-rw-rw-rw- 1 user group 0 Sep 10 00:00 bar
-rw-rw-rw- 1 user group 0 Sep 10 00:00 foo
$ chmod o+x foo$ ls -al foo bar
-rw-rw-rw- 1 user group 0 Sep 10 00:00 bar
-rw-rw-rwx 1 user group 0 Sep 10 00:00 foo
$ chmod u=rwX,g=rX,o=rX foo bar$ ls -al foo bar
-rw-r--r-- 1 user group 0 Sep 10 00:00 bar
-rwxr-xr-x 1 user group 0 Sep 10 00:00 foo
u=rwX,g=rX,o=rX because this won’t make every file executable, only folders.
Careful:
chmod -Xalso looks for any existing exec bits:$ umask 0 $ >foo >bar $ ls -al foo bar -rw-rw-rw- 1 user group 0 Sep 10 00:00 bar -rw-rw-rw- 1 user group 0 Sep 10 00:00 foo $ chmod o+x foo $ ls -al foo bar -rw-rw-rw- 1 user group 0 Sep 10 00:00 bar -rw-rw-rwx 1 user group 0 Sep 10 00:00 foo $ chmod u=rwX,g=rX,o=rX foo bar $ ls -al foo bar -rw-r--r-- 1 user group 0 Sep 10 00:00 bar -rwxr-xr-x 1 user group 0 Sep 10 00:00 foo