Re: is there script to detect if remote machine is alive/reachable w/o using Net::Ping?

Im currenlty using a Redhat Linux and the PING command there seems to also "HANG" on unreachable machines

Did you specify a timeout period for ping? You can use -t to tell ping when you want it to exit. Here's some code that returns true if the remote machine pings at least once in 7 seconds:

sub ping {
  my $ip = shift;
  my $p = `/sbin/ping -c 5 -t 7 $ip | /usr/bin/grep 'packet loss'`;
  unless ( $p =~ /(\d+)% packet loss/ ) {
    die ( "Bad Response:\n$p\n" );
  }
  my $loss = $1;
  print "Loss = $1 ";
  return ( $loss != 100 );
}
[download]

Comment on Re: is there script to detect if remote machine is alive/reachable w/o using Net::Ping? Download Code

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Re: Re: is there script to detect if remote machine is alive/reachable w/o using Net::Ping? by perigeeV (Hermit) on Jun 07, 2002 at 00:41 UTC
Are you on RedHat? iputils-ss001110 uses -t for time-to-live. I've got -w for timeout. Oh well, no matter.	[reply]
Re: Re: Re: is there script to detect if remote machine is alive/reachable w/o using Net::Ping? by Anonymous Monk on Jun 07, 2002 at 05:27 UTC
tnx very much guys! i really appreciated the help. even though my question was not specific. im really sorry about it. my question shouldve been like this: `In general IO::Socket process (regardless of which socket and what typ +e of socket to use) what should be the recommended process to detect +if the remote machines are alive/reachable if you dont want to put a +DIE command after the IO::Socket::INET->new() process? (of course, to + avoid HANG and probably you would have other codes to execute after +the socket connect process...)` [download] The only thing I thought about at that time was PING. And yes I did forget to check the man pages, sorry for that. heres what i did.: sub doit { $host="$aa.$bb.$cc.$dd"; $port="23"; $fnd=""; $pong=`ping -c 3 $host -v`; #is there really a "-t" option here? $fnd=($pong=~m/(...)%/gi); $xcd=$1; if ($xcd!=100) { $remote = IO::Socket::INET -> new ( Proto => "tcp", PeerAddr => $host, PeerPort => $port, Timeout => 1 ); $\| = 1; if ($remote) { close $remote; print "Socket ready..."; } else { print "Try again!"; } } } [download] tnx really a lot for helping me. but i do have one inquiry though. "Is there a way to detect remote machines if they are alive/reachable w/o using NET::Ping and the shell command /sbin/ping?" Hopefully something like a socket command. thank you very much to all those who helped me. Lovelots and mwah, Cherry.	[reply] [d/l] [select]


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