our @ISA = qw
/ Exporter AutoLoader /;
our @EXPORT = qw
/ hostname /;
XSLoader
::load
('Sys::Hostname', $VERSION);
# method 1 - we already know it
return $host if defined $host;
# method 1' - try to ask the system
$host = ghname
() if defined &ghname
;
return $host if defined $host;
# method 2 - no sockets ==> return DECnet node name
eval { local $SIG{__DIE__
}; $host = (gethostbyname('me'))[0] };
if ($@
) { return $host = $ENV{'SYS$NODE'}; }
# method 3 - has someone else done the job already? It's common for the
# TCP/IP stack to advertise the hostname via a logical name. (Are
# there any other logicals which TCP/IP stacks use for the host name?)
$host = $ENV{'ARPANET_HOST_NAME'} || $ENV{'INTERNET_HOST_NAME'} ||
$ENV{'MULTINET_HOST_NAME'} || $ENV{'UCX$INET_HOST'} ||
$ENV{'TCPWARE_DOMAINNAME'} || $ENV{'NEWS_ADDRESS'};
# method 4 - does hostname happen to work?
if ($rslt !~ /IVVERB/) { ($host) = $rslt =~ /^(\S+)/; }
croak
"Cannot get host name of local machine";
elsif ($^O
eq 'MSWin32') {
($host) = gethostbyname('localhost');
chomp($host = `hostname 2> NUL`) unless defined $host;
# is anyone going to make it here?
local $ENV{PATH
} = '/usr/bin:/bin:/usr/sbin:/sbin'; # Paranoia.
# method 2 - syscall is preferred since it avoids tainting problems
# XXX: is it such a good idea to return hostname untainted?
$host = "\0" x
65; ## preload scalar
syscall(&SYS_gethostname
, $host, 65) == 0;
# method 2a - syscall using systeminfo instead of gethostname
# -- needed on systems like Solaris
require "sys/syscall.ph";
require "sys/systeminfo.ph";
$host = "\0" x
65; ## preload scalar
syscall(&SYS_systeminfo
, &SI_HOSTNAME
, $host, 65) != -1;
# method 3 - trusty old hostname command
$host = `(hostname) 2>/dev/null`; # bsdish
# method 4 - use POSIX::uname(), which strictly can't be expected to be
$host = (POSIX
::uname
())[1];
# method 5 - sysV uname command (may truncate)
$host = `uname -n 2>/dev/null`; ## sysVish
# method 6 - Apollo pre-SR10
($host,$a,$b,$c,$d)=split(/[:\. ]/,`/com/host`,6);
|| croak
"Cannot get host name of local machine";
Sys::Hostname - Try every conceivable way to get hostname
Attempts several methods of getting the system hostname and
then caches the result. It tries the first available of the C
library's gethostname(), C<`$Config{aphostname}`>, uname(2),
C<syscall(SYS_gethostname)>, C<`hostname`>, C<`uname -n`>,
and the file F</com/host>. If all that fails it C<croak>s.
All NULs, returns, and newlines are removed from the result.
David Sundstrom E<lt>F<sunds@asictest.sc.ti.com>E<gt>
XS code added by Greg Bacon E<lt>F<gbacon@cs.uah.edu>E<gt>