I've got a problem with UNIX permissions : I'm working under Debian Squeeze, and one of my scripts, run by www-data, needs to move a file, 23550.zip, placed in the home directory of another user, autodo, to a subdirectory in this user's home (/home/autodo/.processed) to mark it as already processed.
I tried to change the group ownership of /home/autodo, /home/autodo/23550.zip and /home/autodo/.processed to the group www-data to allow the www-data user to move this file, but it still fails saying Permission denied, as you can see below (as I'm French, I translated french messages back to English, although I can't be sure the translation is the one displayed in English version of these commands) :
sh-4.1$ ls -lah /home/autodo
total 27M
drwxr-xr-x 3 autodo www-data 4,0K 9 janv. 15:17 .
drwxr-xr-x 88 root root 4,0K 8 janv. 15:21 ..
-rwxr-xr-x 1 autodo ftpusers 4,8K 5 sept. 23:14 19236.zip
-rwxr-xr-x 1 autodo www-data 26M 9 janv. 14:26 23550.zip
-rwxr-xr-x 1 autodo ftpusers 2,3K 6 janv. 20:44 3194.zip
-rwxr-xr-x 1 autodo ftpusers 1,1M 5 sept. 23:38 53274.zip
-rwxr-xr-x 1 autodo ftpusers 585 6 sept. 00:50 70069.zip
-rwxr-xr-x 1 autodo ftpusers 220 16 nov. 15:10 .bash_logout
-rwxr-xr-x 1 autodo ftpusers 3,2K 16 nov. 15:10 .bashrc
drwxr-xr-x 2 autodo www-data 4,0K 9 janv. 15:16 .processed
-rwxr-xr-x 1 autodo ftpusers 675 16 nov. 15:10 .profile
sh-4.1$ ls -lah /home/autodo/.processed
total 66M
drwxr-xr-x 2 autodo www-data 4,0K 9 janv. 15:16 .
drwxr-xr-x 3 autodo www-data 4,0K 9 janv. 15:17 ..
-rwxr-xr-x 1 autodo ftpusers 3,8K 8 janv. 22:42 100583.zip
-rwxr-xr-x 1 autodo ftpusers 1,7K 9 janv. 02:48 12211.zip
-rwxr-xr-x 1 autodo ftpusers 2,2K 8 janv. 22:43 166273.zip
-rwxr-xr-x 1 autodo ftpusers 424K 8 janv. 22:52 193894.zip
-rwxr-xr-x 1 autodo ftpusers 1,2M 9 janv. 01:13 20662.zip
-rwxr-xr-x 1 autodo ftpusers 59M 9 janv. 00:43 22352.zip
-rwxr-xr-x 1 autodo ftpusers 1,2M 8 janv. 22:42 23704.zip
-rwxr-xr-x 1 autodo ftpusers 214K 9 janv. 02:34 24704.zip
-rwxr-xr-x 1 autodo ftpusers 632 9 janv. 01:17 26360.zip
-rwxr-xr-x 1 autodo ftpusers 2,8K 9 janv. 01:03 31795.zip
-rwxr-xr-x 1 autodo ftpusers 106K 9 janv. 00:11 31797.zip
-rwxr-xr-x 1 autodo ftpusers 413K 9 janv. 00:44 31799.zip
-rwxr-xr-x 1 autodo ftpusers 4,4K 8 janv. 22:30 31803.zip
-rwxr-xr-x 1 autodo ftpusers 2,3K 5 janv. 21:19 3194.zip
-rwxr-xr-x 1 autodo ftpusers 13K 8 janv. 23:33 5705.zip
-rwxr-xr-x 1 autodo ftpusers 2,8K 8 janv. 22:19 5858.zip
-rwxr-xr-x 1 autodo ftpusers 86K 9 janv. 04:34 604.zip
-rwxr-xr-x 1 autodo ftpusers 2,6M 9 janv. 03:34 7091.zip
-rwxr-xr-x 1 autodo ftpusers 3,4K 8 janv. 21:25 7878.zip
-rwxr-xr-x 1 autodo ftpusers 752K 9 janv. 03:37 8127.zip
-rwxr-xr-x 1 autodo ftpusers 6,1K 8 janv. 22:01 84846.zip
-rwxr-xr-x 1 autodo ftpusers 358K 9 janv. 02:42 989.zip
sh-4.1$ id
uid=33(www-data) gid=33(www-data) groups=33(www-data),2000(ftpusers)
sh-4.1$ mv /home/autodo/23550.zip /home/autodo/.processed/
mv: unable to move « /home/autodo/23550.zip » to « /home/autodo/.processed/23550.zip »: Permission denied
I also tried to setgid this user's directory, but it also failed with the same Permission denied, and to adduser www-data ftpusers, but it still failed with the same error.
I have to admit that I'm lost; I always thought that the permissions of a group owning a file meant the same than the owner ones, but this problem contradicts this, and I can't think that there can be such a bug in the Linux kernel, so I have to had missed something, but where, dammit!
