1External(3) User Contributed Perl Documentation External(3)
2
6 Net::Ping::External - Cross-platform interface to ICMP "ping" utilities
7
9 In general:
10 use Net::Ping::External qw(ping);
12 ping(%options);
13 Some examples:
15 use Net::Ping::External qw(ping);
17 # Ping a single host
19 my $alive = ping(host => "127.0.0.1");
20 print "127.0.0.1 is online" if $alive;
21 # Or a list of hosts
23 my @hosts = qw(127.0.0.1 127.0.0.2 127.0.0.3 127.0.0.4);
24 my $num_alive = 0;
25 foreach (@hosts) {
26 $alive = ping(hostname => $_, timeout => 5);
27 print "$_ is alive!\n" if $alive;
28 $num_alive++;
29 }
30 print "$num_alive hosts are alive.\n";
31 # Using all the fancy options:
33 ping(hostname => "127.0.0.1", count => 5, size => 1024, timeout => 3);
34
36 Net::Ping::External is a module which interfaces with the "ping"
37 command on many systems. It presently provides a single function,
38 "ping()", that takes in a hostname and (optionally) a timeout and
39 returns true if the host is alive, and false otherwise. Unless you have
40 the ability (and willingness) to run your scripts as the superuser on
41 your system, this module will probably provide more accurate results
42 than Net::Ping will.
43 Why?
45 · ICMP ping is the most reliable way to tell whether a remote host is
47 alive.
48 · However, Net::Ping cannot use an ICMP ping unless you are running
50 your script with privileged (AKA "root") access.
51 · The system's "ping" command uses ICMP and does not usually require
53 privileged access.
54 · While it is relatively trivial to write a Perl script that parses
56 the output of the "ping" command on a given system, the aim of this
57 module is to encapsulate this functionality and provide a single
58 interface for it that works on many systems.
59 ping() OPTIONS
61 This module is still "alpha"; it is expected that more options to the
62 "ping()" function will be added soon.
63 · "host, hostname"
65 The hostname (or dotted-quad IP address) of the remote host you are
67 trying to ping. You must specify either the "hostname" option or
68 the "ip" option.
69 "host" and "hostname" are synonymous.
71 · "ip"
73 A packed bit-string representing the 4-byte packed IP address (as
75 returned by "Socket.pm"'s "inet_aton()" function) of the host that
76 you would like to ping.
77 · "timeout"
79 The maximum amount of time, in seconds, that "ping()" will wait for
81 a response. If the remote system does not respond before the
82 timeout has elapsed, "ping()" will return false.
83 Default value: 5.
85 · "count"
87 The number of ICMP ping packets to send to the remote host.
89 Eventually, Net::Ping::External will return the number of packets
90 that were acknowledged by the remote host; for now, however,
91 "ping()" still returns just true or false.
92 Default value: 1.
94 · "size"
96 Specifies the number of data bytes to be sent. The default is 56,
98 which translates into 64 ICMP data bytes when combined with the 8
99 bytes of ICMP header data.
100 Default value: 56.
102 SUPPORTED PLATFORMS
104 Support currently exists for interfacing with the standard ping
105 utilities on the following systems. Please note that the path to the
106 `ping' should be somewhere in your PATH environment variable (or your
107 system's closest equivalent thereof.) Otherwise, Net::Ping::External
108 will be unable to locate your system's `ping' command.
109 · Win32
111 Tested OK on Win98, Win XP. It should work on other Windows systems
113 as well.
114 · Cygwin
116 Tested OK on Cygwin 1.5.21. Problem is that we may be running
118 windows ping. They have different options.
119 · Linux
121 Tested OK on Debian 2.2 and Redhat 6.2. It appears that different
123 versions of Linux use different versions of ping, which support
124 different options. Not sure how I'm going to resolve this yet; for
125 now, all the options but "count" are disabled.
126 · BSD
128 Tested OK on OpenBSD 2.7 and 3.0, Netbsd 1.5.3, Freebsd 4.6.2, 5.4.
130 Needs testing for BSDi.
131 · Solaris
133 Tested OK on Solaris 2.6 and 2.7.
135 · IRIX
137 Tested OK on IRIX 6.5.
139 · AIX, DEC OSF, UNICOSMK, NeXTStep, HP-UX, BSD/OS (BSDi), BeOS
141 Support for these systems is integrated into this module but none
143 have been tested yet. If you have successful or unsuccessful test
144 results for any of these systems, please send them to me. On some
145 of these systems, some of the arguments may not be supported. If
146 you'd like to see better support on your system, please e-mail me.
147 More systems will be added as soon as any users request them. If your
149 system is not currently supported, e-mail me; adding support to your
150 system is probably trivial.
151
153 This module should be considered alpha. Bugs may exist. Although no
154 specific bugs are known at this time, the module could use testing on a
155 greater variety of systems.
156 See the warning below.
158
160 This module calls whatever "ping" program it first finds in your PATH
161 environment variable. If your PATH contains a trojan "ping" program,
162 this module will call that program. This involves a small amount of
163 risk, but no more than simply typing "ping" at a system prompt.
164 Beware Greeks bearing gifts.
166
168 Alexandr Ciornii (alexchorny AT gmail.com), Colin McMillen (colinm AT
169 cpan.org)
170 This library is free software; you can redistribute it and/or modify it
172 under the same terms as Perl itself.
173
175 Dan Moore contributed command-line options and code for NeXT, BeOS, HP-
176 UX, and BSD/OS.
177 Jarkko Hietaniemi contributed a huge list of command-line options and
179 results for the `ping' command on 9 different systems.
180 Randy Moore contributed several patches for Win32 support.
182 Marc-Andre Dumas contributed a patch for FreeBSD support.
184 Jonathan Stowe fixed a bug in 0.09 that prevented the module from
186 running on some systems.
187 Numerous people sent in a patch to fix a bug in 0.10 that broke ping on
189 Windown systems.
190 Peter N. Lewis contributed a patch that works correctly on Mac OS X
192 10.2 (and hopefully other versions as well).
193
195 Net::Ping
196perl v5.12.0 2007-02-05 External(3)