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External(3)	      User Contributed Perl Documentation	   External(3)

       Net::Ping::External - Cross-platform Perl interface to "ping" utilities

       In general:

	 use Net::Ping::External qw(ping);

       Some examples:

	 use Net::Ping::External qw(ping);

	 # Ping	a single host
	 my $alive = ping(host => "");
	 print " is online" if	$alive;

	 # Or a	list of	hosts
	 my @hosts = qw(;
	 my $num_alive = 0;
	 foreach (@hosts) {
	   $alive = ping(hostname => $_, timeout => 5);
	   print "$_ is	alive!\n" if $alive;
	 print "$num_alive hosts are alive.\n";

	 # Using all the fancy options:
	 ping(hostname => "", count =>	5, size	=> 1024, timeout => 3);

       Net::Ping::External is a	module which interfaces	with the "ping"
       command on many systems.	It presently provides a	single function,
       "ping()", that takes in a hostname and (optionally) a timeout and
       returns true if the host	is alive, and false otherwise. Unless you have
       the ability (and	willingness) to	run your scripts as the	superuser on
       your system, this module	will probably provide more accurate results
       than Net::Ping will.


       o   ICMP	ping is	the most reliable way to tell whether a	remote host is

       o   However, Net::Ping cannot use an ICMP ping unless you are running
	   your	script with privileged (AKA "root") access.

       o   The system's	"ping" command uses ICMP and does not usually require
	   privileged access.

       o   While it is relatively trivial to write a Perl script that parses
	   the output of the "ping" command on a given system, the aim of this
	   module is to	encapsulate this functionality and provide a single
	   interface for it that works on many systems.

   ping() OPTIONS
       This module is still "alpha"; it	is expected that more options to the
       "ping()"	function will be added soon.

       o   "host, hostname"

	   The hostname	(or dotted-quad	IP address) of the remote host you are
	   trying to ping. You must specify either the "hostname" option or
	   the "ip" option.

	   "host" and "hostname" are synonymous.

       o   "ip"

	   A packed bit-string representing the	4-byte packed IP address (as
	   returned by ""'s "inet_aton()" function) of	the host that
	   you would like to ping.

       o   "timeout"

	   The maximum amount of time, in seconds, that	"ping()" will wait for
	   a response.	If the remote system does not respond before the
	   timeout has elapsed,	"ping()" will return false.

	   Default value: 5.

       o   "count"

	   The number of ICMP ping packets to send to the remote host.
	   Eventually, Net::Ping::External will	return the number of packets
	   that	were acknowledged by the remote	host; for now, however,
	   "ping()" still returns just true or false.

	   Default value: 1.

       o   "size"

	   Specifies the number	of data	bytes to be sent.  The default is 56,
	   which translates into 64 ICMP data bytes when combined with the 8
	   bytes of ICMP header	data.

	   Default value: 56.

       Support currently exists	for interfacing	with the standard ping
       utilities on the	following systems. Please note that the	path to	the
       `ping' should be	somewhere in your PATH environment variable (or	your
       system's	closest	equivalent thereof.) Otherwise,	Net::Ping::External
       will be unable to locate	your system's `ping' command.

       o   Win32

	   Tested OK on	Win98, Win XP. It should work on other Windows systems
	   as well.

       o   Cygwin

	   Tested OK on	Cygwin 1.5.21. Problem is that we may be running
	   windows ping.  They have different options.

       o   Linux

	   Tested OK on	Debian 2.2 and Redhat 6.2. It appears that different
	   versions of Linux use different versions of ping, which support
	   different options.  Not sure	how I'm	going to resolve this yet; for
	   now,	all the	options	but "count" are	disabled.

       o   BSD

	   Tested OK on	OpenBSD	2.7 and	3.0, Netbsd 1.5.3, Freebsd 4.6.2, 5.4.
	   Needs testing for BSDi.

       o   Solaris

	   Tested OK on	Solaris	2.6 and	2.7.

       o   IRIX

	   Tested OK on	IRIX 6.5.


	   Support for these systems is	integrated into	this module but	none
	   have	been tested yet. If you	have successful	or unsuccessful	test
	   results for any of these systems, please send them to me. On	some
	   of these systems, some of the arguments may not be supported. If
	   you'd like to see better support on your system, please e-mail me.

       More systems will be added as soon as any users request them. If	your
       system is not currently supported, e-mail me; adding support to your
       system is probably trivial.

       This module should be considered	beta. Bugs may exist. Although no
       specific	bugs are known at this time, the module	could use testing on a
       greater variety of systems.

       See the warning below.

       This module calls whatever "ping" program it first finds	in your	PATH
       environment variable. If	your PATH contains a trojan "ping" program,
       this module will	call that program. This	involves a small amount	of
       risk, but no more than simply typing "ping" at a	system prompt.

       Beware Greeks bearing gifts.

       Alexandr	Ciornii	(alexchorny AT, Colin McMillen (colinm AT

       This library is free software; you can redistribute it and/or modify it
       under the same terms as Perl itself.

       Dan Moore contributed command-line options and code for NeXT, BeOS, HP-
       UX, and BSD/OS.

       Jarkko Hietaniemi contributed a huge list of command-line options and
       results for the `ping' command on 9 different systems.

       Randy Moore contributed several patches for Win32 support.

       Marc-Andre Dumas	contributed a patch for	FreeBSD	support.

       Jonathan	Stowe fixed a bug in 0.09 that prevented the module from
       running on some systems.

       Numerous	people sent in a patch to fix a	bug in 0.10 that broke ping on
       Windows systems.

       Peter N.	Lewis contributed a patch that works correctly on Mac OS X
       10.2 (and hopefully other versions as well).


perl v5.32.1			  2014-04-12			   External(3)


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