Profile of Sys/Hostname.pm

Filename	/usr/lib/x86_64-linux-gnu/perl/5.20/Sys/Hostname.pm
Statements	Executed 17 statements in 592µs

Subroutines
Calls	P	F	Exclusive Time	Inclusive Time	Subroutine
1	1	1	13µs	132µs	Sys::Hostname::::BEGIN@16Sys::Hostname::BEGIN@16
1	1	1	12µs	22µs	Sys::Hostname::::BEGIN@3Sys::Hostname::BEGIN@3
1	1	1	6µs	32µs	Sys::Hostname::::BEGIN@5Sys::Hostname::BEGIN@5
0	0	0	0s	0s	Sys::Hostname::::hostnameSys::Hostname::hostname

Call graph for these subroutines as a Graphviz dot language file.

Line	State ments	Time on line	Calls	Time in subs	Code
1					package Sys::Hostname;
2
3	2	24µs	2	32µs	# spent 22µs (12+10) within Sys::Hostname::BEGIN@3 which was called: # once (12µs+10µs) by Mail::Sendmail::BEGIN@56 at line 3 use strict; # spent 22µs making 1 call to Sys::Hostname::BEGIN@3 # spent 10µs making 1 call to strict::import
4
5	2	88µs	2	58µs	# spent 32µs (6+26) within Sys::Hostname::BEGIN@5 which was called: # once (6µs+26µs) by Mail::Sendmail::BEGIN@56 at line 5 use Carp; # spent 32µs making 1 call to Sys::Hostname::BEGIN@5 # spent 26µs making 1 call to Exporter::import
6
7	1	600ns			require Exporter;
8
9	1	5µs			our @ISA = qw/ Exporter /;
10	1	400ns			our @EXPORT = qw/ hostname /;
11
12	1	0s			our $VERSION;
13
14	1	0s			our $host;
15
16					# spent 132µs (13+118) within Sys::Hostname::BEGIN@16 which was called: # once (13µs+118µs) by Mail::Sendmail::BEGIN@56 at line 26 BEGIN {
17	1	300ns			$VERSION = '1.18';
18					{
19	2	4µs			local $SIG{__DIE__};
20	1	2µs			eval {
21	1	700ns			require XSLoader;
22	1	123µs	1	118µs	XSLoader::load(); # spent 118µs making 1 call to XSLoader::load
23					};
24	1	1µs			warn $@ if $@;
25					}
26	1	340µs	1	132µs	} # spent 132µs making 1 call to Sys::Hostname::BEGIN@16
27
28
29					sub hostname {
30
31					# method 1 - we already know it
32					return $host if defined $host;
33
34					# method 1' - try to ask the system
35					$host = ghname() if defined &ghname;
36					return $host if defined $host;
37
38					if ($^O eq 'VMS') {
39
40					# method 2 - no sockets ==> return DECnet node name
41					eval { local $SIG{__DIE__}; $host = (gethostbyname('me'))[0] };
42					if ($@) { return $host = $ENV{'SYS$NODE'}; }
43
44					# method 3 - has someone else done the job already? It's common for the
45					# TCP/IP stack to advertise the hostname via a logical name. (Are
46					# there any other logicals which TCP/IP stacks use for the host name?)
47					$host = $ENV{'ARPANET_HOST_NAME'} \|\| $ENV{'INTERNET_HOST_NAME'} \|\|
48					$ENV{'MULTINET_HOST_NAME'} \|\| $ENV{'UCX$INET_HOST'} \|\|
49					$ENV{'TCPWARE_DOMAINNAME'} \|\| $ENV{'NEWS_ADDRESS'};
50					return $host if $host;
51
52					# method 4 - does hostname happen to work?
53					my($rslt) = `hostname`;
54					if ($rslt !~ /IVVERB/) { ($host) = $rslt =~ /^(\S+)/; }
55					return $host if $host;
56
57					# rats!
58					$host = '';
59					croak "Cannot get host name of local machine";
60
61					}
62					elsif ($^O eq 'MSWin32') {
63					($host) = gethostbyname('localhost');
64					chomp($host = `hostname 2> NUL`) unless defined $host;
65					return $host;
66					}
67					else { # Unix
68					# is anyone going to make it here?
69
70					local $ENV{PATH} = '/usr/bin:/bin:/usr/sbin:/sbin'; # Paranoia.
71
72					# method 2 - syscall is preferred since it avoids tainting problems
73					# XXX: is it such a good idea to return hostname untainted?
74					eval {
75					local $SIG{__DIE__};
76					require "syscall.ph";
77					$host = "\0" x 65; ## preload scalar
78					syscall(&SYS_gethostname, $host, 65) == 0;
79					}
80
81					# method 2a - syscall using systeminfo instead of gethostname
82					# -- needed on systems like Solaris
83					\|\| eval {
84					local $SIG{__DIE__};
85					require "sys/syscall.ph";
86					require "sys/systeminfo.ph";
87					$host = "\0" x 65; ## preload scalar
88					syscall(&SYS_systeminfo, &SI_HOSTNAME, $host, 65) != -1;
89					}
90
91					# method 3 - trusty old hostname command
92					\|\| eval {
93					local $SIG{__DIE__};
94					local $SIG{CHLD};
95					$host = `(hostname) 2>/dev/null`; # BSDish
96					}
97
98					# method 4 - use POSIX::uname(), which strictly can't be expected to be
99					# correct
100					\|\| eval {
101					local $SIG{__DIE__};
102					require POSIX;
103					$host = (POSIX::uname())[1];
104					}
105
106					# method 5 - sysV uname command (may truncate)
107					\|\| eval {
108					local $SIG{__DIE__};
109					$host = `uname -n 2>/dev/null`; ## sysVish
110					}
111
112					# bummer
113					\|\| croak "Cannot get host name of local machine";
114
115					# remove garbage
116					$host =~ tr/\0\r\n//d;
117					$host;
118					}
119					}
120
121	1	3µs			1;
122
123					__END__