Sys::Hostname fails under Solaris 2.5 when setuid

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

diff --git a/lib/Sys/Hostname.pm b/lib/Sys/Hostname.pm
index 4dd4fe2..7fe3d8f 100644 (file)
--- a/lib/Sys/Hostname.pm
+++ b/lib/Sys/Hostname.pm
@@ -1,6 +1,3 @@
-# by David Sundstrom   sunds@asictest.sc.ti.com
-#    Texas Instruments
-
 package Sys::Hostname;
 
 use Carp;
@@ -8,17 +5,71 @@ require Exporter;
 @ISA = qw(Exporter);
 @EXPORT = qw(hostname);
 
-#
-# Try every conceivable way to get hostname.
-# 
+=head1 NAME
+
+Sys::Hostname - Try every conceivable way to get hostname
+
+=head1 SYNOPSIS
+
+    use Sys::Hostname;
+    $host = hostname;
+
+=head1 DESCRIPTION
+
+Attempts several methods of getting the system hostname and
+then caches the result.  It tries C<syscall(SYS_gethostname)>,
+C<`hostname`>, C<`uname -n`>, and the file F</com/host>.
+If all that fails it C<croak>s.
+
+All nulls, returns, and newlines are removed from the result.
+
+=head1 AUTHOR
+
+David Sundstrom E<lt>F<sunds@asictest.sc.ti.com>E<gt>
+
+Texas Instruments
+
+=cut
 
 sub hostname {
 
-    # method 1 - we already know it
-    return $host if defined $host;
+  # method 1 - we already know it
+  return $host if defined $host;
+
+  if ($^O eq 'VMS') {
+
+    # 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'};
+    return $host if $host;
+
+    # method 4 - does hostname happen to work?
+    my($rslt) = `hostname`;
+    if ($rslt !~ /IVVERB/) { ($host) = $rslt =~ /^(\S+)/; }
+    return $host if $host;
+
+    # rats!
+    $host = '';
+    Carp::croak "Cannot get host name of local machine";  
+
+  }
+  elsif ($^O eq 'MSWin32') {
+    ($host) = gethostbyname('localhost');
+    chomp($host = `hostname 2> NUL`) unless defined $host;
+    return $host;
+  }
+  else {  # Unix
 
     # method 2 - syscall is preferred since it avoids tainting problems
     eval {
+       local $SIG{__DIE__};
        {
            package main;
            require "syscall.ph";
@@ -27,18 +78,33 @@ sub hostname {
        syscall(&main::SYS_gethostname, $host, 65) == 0;
     }
 
+    # method 2a - syscall using systeminfo instead of gethostname
+    #           -- needed on systems like Solaris
+    || eval {
+      {
+          package main;
+          require "sys/syscall.ph";
+          require "sys/systeminfo.ph";
+      }
+      $host = "\0" x 65; ## preload scalar
+      syscall(&main::SYS_systeminfo, &main::SI_HOSTNAME, $host, 65) != -1;
+    }
+
     # method 3 - trusty old hostname command
     || eval {
+       local $SIG{__DIE__};
        $host = `(hostname) 2>/dev/null`; # bsdish
     }
 
     # method 4 - sysV uname command (may truncate)
     || eval {
+       local $SIG{__DIE__};
        $host = `uname -n 2>/dev/null`; ## sysVish
     }
 
     # method 5 - Apollo pre-SR10
     || eval {
+       local $SIG{__DIE__};
        ($host,$a,$b,$c,$d)=split(/[:\. ]/,`/com/host`,6);
     }
 
@@ -48,6 +114,7 @@ sub hostname {
     # remove garbage 
     $host =~ tr/\0\r\n//d;
     $host;
+  }
 }
 
 1;