Commit | Line | Data |
---|---|---|
a0d0e21e | 1 | package Sys::Hostname; |
8990e307 | 2 | |
a0d0e21e | 3 | use Carp; |
8990e307 | 4 | require Exporter; |
a0d0e21e LW |
5 | @ISA = qw(Exporter); |
6 | @EXPORT = qw(hostname); | |
8990e307 | 7 | |
cb1a09d0 AD |
8 | =head1 NAME |
9 | ||
10 | Sys::Hostname - Try every conceivable way to get hostname | |
11 | ||
12 | =head1 SYNOPSIS | |
13 | ||
14 | use Sys::Hostname; | |
15 | $host = hostname; | |
16 | ||
17 | =head1 DESCRIPTION | |
18 | ||
19 | Attempts several methods of getting the system hostname and | |
20 | then caches the result. It tries C<syscall(SYS_gethostname)>, | |
21 | C<`hostname`>, C<`uname -n`>, and the file F</com/host>. | |
22 | If all that fails it C<croak>s. | |
23 | ||
24 | All nulls, returns, and newlines are removed from the result. | |
25 | ||
26 | =head1 AUTHOR | |
27 | ||
1fef88e7 | 28 | David Sundstrom E<lt>F<sunds@asictest.sc.ti.com>E<gt> |
cb1a09d0 AD |
29 | |
30 | Texas Instruments | |
31 | ||
32 | =cut | |
8990e307 LW |
33 | |
34 | sub hostname { | |
a0d0e21e | 35 | |
567d72c2 | 36 | # method 1 - we already know it |
37 | return $host if defined $host; | |
38 | ||
c5f45532 | 39 | if ($^O eq 'VMS') { |
567d72c2 | 40 | |
41 | # method 2 - no sockets ==> return DECnet node name | |
84902520 | 42 | eval { local $SIG{__DIE__}; $host = (gethostbyname('me'))[0] }; |
c5f45532 | 43 | if ($@) { return $host = $ENV{'SYS$NODE'}; } |
567d72c2 | 44 | |
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 $host; | |
52 | ||
53 | # method 4 - does hostname happen to work? | |
54 | my($rslt) = `hostname`; | |
55 | if ($rslt !~ /IVVERB/) { ($host) = $rslt =~ /^(\S+)/; } | |
56 | return $host if $host; | |
57 | ||
58 | # rats! | |
c5f45532 | 59 | $host = ''; |
567d72c2 | 60 | Carp::croak "Cannot get host name of local machine"; |
61 | ||
62 | } | |
7bac28a0 | 63 | elsif ($^O eq 'MSWin32') { |
64 | ($host) = gethostbyname('localhost'); | |
65 | chomp($host = `hostname 2> NUL`) unless defined $host; | |
66 | return $host; | |
67 | } | |
567d72c2 | 68 | else { # Unix |
8990e307 LW |
69 | |
70 | # method 2 - syscall is preferred since it avoids tainting problems | |
71 | eval { | |
84902520 | 72 | local $SIG{__DIE__}; |
a0d0e21e LW |
73 | { |
74 | package main; | |
75 | require "syscall.ph"; | |
76 | } | |
8990e307 | 77 | $host = "\0" x 65; ## preload scalar |
a0d0e21e | 78 | syscall(&main::SYS_gethostname, $host, 65) == 0; |
8990e307 LW |
79 | } |
80 | ||
67693aa5 TB |
81 | # method 2a - syscall using systeminfo instead of gethostname |
82 | # -- needed on systems like Solaris | |
83 | || eval { | |
84 | local $SIG{__DIE__}; | |
85 | { | |
86 | package main; | |
87 | require "sys/syscall.ph"; | |
88 | require "sys/systeminfo.ph"; | |
89 | } | |
90 | $host = "\0" x 65; ## preload scalar | |
91 | syscall(&main::SYS_systeminfo, &main::SI_HOSTNAME, $host, 65) != -1; | |
92 | } | |
93 | ||
85e6fe83 | 94 | # method 3 - trusty old hostname command |
8990e307 | 95 | || eval { |
84902520 | 96 | local $SIG{__DIE__}; |
a0d0e21e | 97 | $host = `(hostname) 2>/dev/null`; # bsdish |
8990e307 LW |
98 | } |
99 | ||
85e6fe83 | 100 | # method 4 - sysV uname command (may truncate) |
8990e307 | 101 | || eval { |
84902520 | 102 | local $SIG{__DIE__}; |
85e6fe83 | 103 | $host = `uname -n 2>/dev/null`; ## sysVish |
8990e307 LW |
104 | } |
105 | ||
106 | # method 5 - Apollo pre-SR10 | |
107 | || eval { | |
84902520 | 108 | local $SIG{__DIE__}; |
8990e307 LW |
109 | ($host,$a,$b,$c,$d)=split(/[:\. ]/,`/com/host`,6); |
110 | } | |
111 | ||
112 | # bummer | |
a0d0e21e | 113 | || Carp::croak "Cannot get host name of local machine"; |
8990e307 LW |
114 | |
115 | # remove garbage | |
116 | $host =~ tr/\0\r\n//d; | |
117 | $host; | |
567d72c2 | 118 | } |
8990e307 LW |
119 | } |
120 | ||
121 | 1; |