-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Mon, Jan 04, 2016 at 03:25:02PM -0500, Gary Dale wrote: > On 04/01/16 12:14 PM, to...@tuxteam.de wrote:
[...] > >Dunno about systemctl, but FWIW you can't change the permissions of > >a symlink. It's always "all on". > > > > > Interesting. Why do they behave that way? Hard links don't (but > replacing the symlink with a hardlink would fail if /bin & /sbin > were on different devices. Also, I gather that systemctl looks at > how it is called to determine the action it needs to take - would > that create a problem if called from a hard link instead of a > symlink?). Perhaps I was a bit cavalier with my "all on": applications *doing* something useful with a symlink reference it (except things like "rm", of course). Thus, the permissions of the referenced-to file apply. Otherwise -- imagine: I do an ln -s /bin/bash $HOME, chmod u+w $HOME/bas (since I own the link) and now have write access to the system shell?! Hard links are a completely different kind of animal: they are alternative directory entries for the same blob of data. Consequently, there is no "primary" (as there is in symlinks). There are no dangling hardlinks (unless your file system is corrupted). As you can well imagine, some restrictions apply in the creation of hardlinks: tomas@rasputin:~$ sudo useradd -m test [sudo] password for tomas: tomas@rasputin:~$ ls -al /home/test total 20 drwxr-xr-x 2 test test 4096 Jan 4 21:50 . drwxr-xr-x 9 root root 4096 Jan 4 21:50 .. -rw-r--r-- 1 test test 220 Apr 10 2010 .bash_logout -rw-r--r-- 1 test test 3392 Jul 13 2012 .bashrc -rw-r--r-- 1 test test 675 Apr 10 2010 .profile tomas@rasputin:~$ ln /home/test/.profile test-profile ln: failed to create hard link `test-profile' => `/home/test/.profile': Operation not permitted Regards - -- tomás -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAlaK2GoACgkQBcgs9XrR2kZg+QCfQoqu5lph/Nh7ZyDOFv0jwG7y aDkAn29+qk8cLS3je2DKwMUk3lvt2o3F =8Nmr -----END PGP SIGNATURE-----
