toadi has asked for the wisdom of the Perl Monks concerning the following question:

hello,

I know this is not really a perl question but I don't know where to ask else.

I have written a perl daemon that has to be run as a regular user. Not as root.

I have written a Sysv startup script where I start my script when the system boots. But this happens as root so my perl daemon runs as root.

This is something I don't want.

Any Suggestions????



--
My opinions may have changed,
but not the fact that I am right

2004-10-27 Edited by Arunbear: Changed title from 'daemons, Sysv, etc.', as per Monastery guidelines

  • Comment on Running a daemon process as another user

Replies are listed 'Best First'.
Re: Running a daemon process as another user
by Zaxo (Archbishop) on Oct 27, 2004 at 08:00 UTC

    At the top of the script, say 

    use POSIX qw/setuid setsid/;
BEGIN {
    setuid scalar getpwnam 'toadi' or die $!;
}

    [download]
    I've imported setsid, too, since you need it to manifest a daemon.

    After Compline,
    Zaxo

[reply]
[d/l]
      ok this is very strange: 
      use POSIX qw/setuid setsid/;

BEGIN {
 setuid scalar getpwnam 'qf3' or die $!;
 # Fork.
 my $pidFile = '/some/path/pid';
 my $pid = fork;
 if ($pid) # parent: save PID
 {
  open PIDFILE, ">$pidFile" or die "can't open $pidFile: $!\n";
  print PIDFILE $pid;
  close PIDFILE;
  exit 0;
 }
}

print "USER: ". getpwuid($<) . "\n";

      [download]

      USER will be root, but when I do a ps -ef it does: 

      toadi      20510     1 14 04:56 pts/0    00:00:01 /usr/bin/perl /some/
+path/daemon

      [download]


      --
      My opinions may have changed,
      but not the fact that I am right

[reply]
[d/l]
[select]

        print "USER: ". getpwuid($<) . "\n";

        USER will be root, but when I do a ps -ef it does:

        Sure it is, because   $<   is the real uid (you used to be root).

        Use the effective uid   $>   to display the new identity. See  perlvar.

        Cheers, Sören

[reply]
Re: Running a daemon process as another user
by gaal (Parson) on Oct 27, 2004 at 08:22 UTC
    Either make the script voluntarily drop privileges (set both $> and $< to your target uid when the script starts), or change users before invoking the script, for example with the system su -c.
[reply]
[d/l]
[select]
      su -c worked


      --
      My opinions may have changed,
      but not the fact that I am right

[reply]
Re: Running a daemon process as another user
by chb (Deacon) on Oct 27, 2004 at 08:01 UTC
    Just use the su command in your startup script to call the perl daemon. Read 'man su' for details.
[reply]

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