perl 5.000

[p5sagit/p5-mst-13.2.git] / lib / Sys / Hostname.pm

# by David Sundstrom   sunds@asictest.sc.ti.com
#    Texas Instruments

package Sys::Hostname;

use Carp;
require Exporter;
@ISA = qw(Exporter);
@EXPORT = qw(hostname);

#
# Try every conceivable way to get hostname.
# 

sub hostname {

    # method 1 - we already know it
    return $host if defined $host;

    # method 2 - syscall is preferred since it avoids tainting problems
    eval {
	{
	    package main;
	    require "syscall.ph";
	}
	$host = "\0" x 65; ## preload scalar
	syscall(&main::SYS_gethostname, $host, 65) == 0;
    }

    # method 3 - trusty old hostname command
    || eval {
	$host = `(hostname) 2>/dev/null`; # bsdish
    }

    # method 4 - sysV uname command (may truncate)
    || eval {
	$host = `uname -n 2>/dev/null`; ## sysVish
    }

    # method 5 - Apollo pre-SR10
    || eval {
	($host,$a,$b,$c,$d)=split(/[:\. ]/,`/com/host`,6);
    }

    # bummer
    || Carp::croak "Cannot get host name of local machine";  

    # remove garbage 
    $host =~ tr/\0\r\n//d;
    $host;
}

1;