Re: mysqld and multilog

On Mon, 22 Nov 2004, Laurent Bercot wrote:

>  --log=/dev/fd/1
>  "Could not use /dev/fd/1 for logging (error 13)."
>  13 means EACCES.
>  I don't understand why it doesn't work, but it doesn't work.

I've been surprised by this once or twice before in a changed-uid environment
with magic /dev files.  /dev/fd/1 may be a symlink to an inherited pty opened
under a bygone uid, which pty the runtime user has no privileges to re-open.

For example, on my system, if I change uid to 'mysql' from a root shell, and
then try to re-open /dev/fd/1, I also get EACCES:

   $ id
   uid=101(mysql) gid=101(mysql) groups=101(mysql)
   $ ls -Hl /dev/fd/1
   crw--w----    1 root      tty      136,   5 Nov 24 00:30 /dev/fd/1
   $ perl -e 'printf("%s (error %d)\n", $!, $!+0) unless defined open(F, shift)' /dev/fd/1
   Permission denied (error 13)

Regards,
Mike