For enlightenment on this question, try

  print `ping host1 -c 1`;
[download]

You probably want to be using the system command instead of using backticks. Backticks capture the output of the command and return it to the Perl program. The system command, however, goes off and executes the program, returning the exit value to the Perl program. That seems to be what you want for the if condition, where you're checking for a return value of 0 (successful exit). For the ssh command inside the if block, maybe take a look at the exec command. It starts the given command, replacing the running Perl program, which it kind of looks like you want to do. Maybe give us a better idea of what the intended operation of your program is and we can help a bit more.

kelan

Perl6 Grammar Student

I've always been a fan of IPC::Open3 for things like this. With it, you can catch and manipulate STDIN, STDOUT, and STDERR, and it makes things like ping, ssh, rsync and rlogin type-tasks very easy.

You could also look into Net::Ping, Net::SSH, File::Rsync, and File::Remote, depending on exactly what it is you're trying to do on that remote system.

`Backticks` are almost never what you want to use, the most-obvious reason being the glaring security implications.

use strict;
use warnings;
use Net::SSH::Perl;

my $user = '';
my $pass = '';
my @host = qw(host1 host2);

for my $host (@host) {
   my $ssh = Net::SSH::Perl->new($host, protocol => "2,1");
   $ssh->login($user,$pass);
   
   my ($stdout, $stderr, $exit) = $ssh->cmd('hostname');
   print STDOUT $stdout if $stdout;
   print STDERR $stderr if $stderr;
   print "remote command exited with [$exit]\n";
}
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jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)

#!/usr/bin/perl -w

use Net::Ping;
use strict;


my @hosts = qw(www.gellyfish.com petunia.gellyfish.com);

my $ping = Net::Ping->new('icmp');

foreach my $host ( @hosts )
{
     if ( $ping->ping($host) )
     {
       print "$host OK\n";
     }
}
[download]