El Lunes, 14 de Diciembre de 2009, aalfred escribi
> It is almost certainly a permission issue. Check it again.
> I've tested and it works fine.
> Only when directory was unreadable I got same result (error) as you
> had.

I've re-checked:

In terminal shell:

---------------
alice@ibc-laptop:/$ whoami
=> alice

alice@ibc-laptop:/$ pwd
=> /

alice@ibc-laptop:/$ cd /home/ibc

alice@ibc-laptop:/home/ibc$
---------------


In irb using "su":

--------------
root@ibc_laptop:/# whoami
=> root

root@ibc_laptop:/# su alice

alice@ibc-laptop:/$ pwd
=> /

alice@ibc-laptop:/$ irb -r "/tmp/kernel_su.rb"

irb> require "fileutils"
=> true

irb> su("alice", "alice") do Dir.chdir("/home/ibc") ; end
(irb):2:in `chdir': Permission denied - /home/ibc (Errno::EACCES)
        from (irb):2:in `block in irb_binding'
        from /tmp/kernel.rb:11:in `block in su'
        from /tmp/kernel.rb:9:in `fork'
        from /tmp/kernel.rb:9:in `su'
        from (irb):1:in `irb_binding'

irb> su("alice") do Dir.chdir("/home/ibc") ; end
(irb):3:in `chdir': Permission denied - /home/ibc (Errno::EACCES)
        from (irb):3:in `block in irb_binding'
        from /tmp/kernel.rb:11:in `block in su'
        from /tmp/kernel.rb:9:in `fork'
        from /tmp/kernel.rb:9:in `su'
        from (irb):1:in `irb_binding'

irb> su("openxdms", "ibc_grp") do Dir.chdir("/home/ibc") ; end
=> #<Process::Status: pid 10824 exit 0>
--------------



> Just a notice: there is a slight difference in your tests:

Yes, I cannot access to /home/ibc directory doing:

  su "alice", "alice" do Dir.chdir("/home/ibc") ; end

but I can access doing:

  su "alice", "ibc_grp" do Dir.chdir("/home/ibc") ; end


Note that "alice" has "alice" has primary group but also belongs to "ibc_grp" 
group:

~# id alice
uid=1003(alice) gid=1003(alice) grupos=1003(alice),1004(ibc_priv)

~# ll -d /home/ibc
drwxr-x--- 77 ibc ibc_grp 4,0K 2009-12-14 09:50 /home/ibc/




-- 
Iñáki Baz Castillo <ibc / aliax.net>