Coreutils 8.32 (and possibly earlier) "mkdir -m <mode> ..." appears to ignore parts of the mode specification. POSIX suggests that with -m specified, the mode is "relative" to a=rwx. That implies a mode of "o-w" should yield a mode of "rwxrwxr-x", and a mode of "o+w" should yield "rwxrwxrwx". Instead:
$ mkdir -m o-w t1 $ mkdir -m o+w t2 $ ls -l total 8 drwxr-xr-x 2 davmac users 4096 Jan 15 17:27 t1 drwxrwxrwx 2 davmac users 4096 Jan 15 17:27 t2 $ So, the "o+w" or "o-w" selects the "other" permissions but also the "group" permissions. This also happens with "g+w" and "g-w" (i.e. both "group" and "other" permissions get set or cleared). This implies it's not just a case of the initial mode not matching POSIX, but somehow "o" and "g" are being applied incorrectly. Setting POSIXLY_CORRECT makes no difference.
