7 @EXPORT = qw(hostname);
11 Sys::Hostname - Try every conceivable way to get hostname
20 Attempts several methods of getting the system hostname and
21 then caches the result. It tries C<syscall(SYS_gethostname)>,
22 C<`hostname`>, C<`uname -n`>, and the file F</com/host>.
23 If all that fails it C<croak>s.
25 All nulls, returns, and newlines are removed from the result.
29 David Sundstrom <sunds@asictest.sc.ti.com>
37 # method 1 - we already know it
38 return $host if defined $host;
40 if ($Config{'osname'} eq 'VMS') {
42 # method 2 - no sockets ==> return DECnet node name
43 if (!$Config{'d_has_sockets'}) { return $host = $ENV{'SYS$NODE'}; }
45 # method 3 - has someone else done the job already? It's common for the
46 # TCP/IP stack to advertise the hostname via a logical name. (Are
47 # there any other logicals which TCP/IP stacks use for the host name?)
48 $host = $ENV{'ARPANET_HOST_NAME'} || $ENV{'INTERNET_HOST_NAME'} ||
49 $ENV{'MULTINET_HOST_NAME'} || $ENV{'UCX$INET_HOST'} ||
50 $ENV{'TCPWARE_DOMAINNAME'} || $ENV{'NEWS_ADDRESS'};
51 return $host if $host;
53 # method 4 - does hostname happen to work?
54 my($rslt) = `hostname`;
55 if ($rslt !~ /IVVERB/) { ($host) = $rslt =~ /^(\S+)/; }
56 return $host if $host;
59 Carp::croak "Cannot get host name of local machine";
64 # method 2 - syscall is preferred since it avoids tainting problems
70 $host = "\0" x 65; ## preload scalar
71 syscall(&main::SYS_gethostname, $host, 65) == 0;
74 # method 3 - trusty old hostname command
76 $host = `(hostname) 2>/dev/null`; # bsdish
79 # method 4 - sysV uname command (may truncate)
81 $host = `uname -n 2>/dev/null`; ## sysVish
84 # method 5 - Apollo pre-SR10
86 ($host,$a,$b,$c,$d)=split(/[:\. ]/,`/com/host`,6);
90 || Carp::croak "Cannot get host name of local machine";
93 $host =~ tr/\0\r\n//d;