how to expand a perl variable within a unix command

[mnew]

Hi, i have just started using Perl and I'm trying to expand a perl variable within a Unix command in the perl script, for example: -

foreach $host (@lines)

{

        print "$host\n";
        $sshcmd = "ssh";
        $get = `$sshcmd $host "uptime"`;
        print "$get\n";

}

I want to use the contents of $host for the hostname but when i run the script it just hangs. if anyone could let me know how to expand the variable within the Unix command that would be great.

Thanks

[RonB]

What makes you think it's not expanding/interpolating the variable?

It's most likely waiting for user input for the username/password.

[mnew]

Hi RonB

If i explicitly specify a hostname instead of $host it works, but nothing happens when I replace the real hostname with $host variable. Also, no username and password is required as I am using ssh keys to connect to all of the servers in my array.

[RonB]

$host does not hold the value you think it holds.

Add this just before the foreach loop and post its output.

use Data::Dumper;
print Dumper \@lines;

Also, always post your code within the code tags, as I did. The code tag button is not available in the "Quick Reply" window. You need to click on the "Go Advanced" button to get it and the other features.

[mnew]

Sure, below are my hostnames: -

bash-3.00# ./check.pl
$VAR1 = [
          'lonprodd1
',
          'cradevd1
',
          'lonprodgz1
'
        ];

[RonB]

That shows that your hostnames need to have the "\n" stripped off.

foreach my $host (@lines)
{
    [B]chomp $host;[/B]
    print "$host\n";
    $sshcmd = "ssh";
    $get = `$sshcmd $host uptime`;
    print "$get\n";
}

[mnew]

Oh man, can't believe I missed that. Thanks for your help Ron, it working fine now.