I've deployed a forking server which appears to be having problems on FreeBSD versions 3.2 and below.

 This is my code:

use English;               # Avoid $<, etc.

my $username = "nobody";

my ($n,$p, $u,$g, $q,$c,$gc,$dir,$sh);
($n,$p, $u,$g, $q,$c,$gc,$dir,$sh)=getpwnam( $username );

# If we have a uid + gid switch to it.
if ( defined( $u ) and defined( $g ) )
{
    # NOTE: Switch GID first - because once switching UID.
    #       switching GID fails.
        #
    $GID = $g;
    $EGID= $g;
    $UID = $u;
    $EUID= $u;
}

[download]

 This setting of GID, EGID, UID, and EUID fails due to broken implementations of setruid() on this platform.

 So my question? Is there a sane way to switch UID+GID that will work on FreeBSD in perl? Or a simple way to test for FreeBSD systems to avoid this breakage?

 I know I could test $^O - but I'm not sure what a FreeBSD machine would produce.

 I guess to detect the failure I can try reading back the values after the switch - but if it fails there's not a lot I can do.

Steve
---
steve.org.uk

In reply to Problem switching UID + GID under FreeBSD by skx

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