Assuming $rh is connected to the appropriate host and you have successfully authenticated (to what looks like a Juniper device?), the main problem here seems to be your while(){} loop which will never end but (assuming ->cmd() ever exists) will keep executing the same command over and over, assigning the output to a variable that immediately goes out of lexical scope.

Adding use strict; use warnings; would have pointed this out to you btw.

Having worked quite a bit with Juniper devices myself, I used Net::Telnet::Cisco but had to customize the "prompt" setting in order to get ->cmd() to work as expected. If you are using that module and didn't set the appropriate "prompt" setting, then ->cmd() will hang indefinitely while waiting for a Cisco command prompt, which is a little different.

I know I'm guessing a lot here, but I hope it helps. FYI, here's how I do it with MX, EX and SRX series -- seems to work pretty well:
@lines = $session->cmd( String => 'show version | no-more', Prompt => '/\n\S+\>/');

Putting it all together, try this: 

use strict;
use warnings;

# Open your $rh and authenticate here
# ...

open(my $fh, "+>>default_ve.txt") || die "Couldn't open file: $!";
my @lines = $rh->cmd(String => 'show version | no-more', Prompt => '/\
+n\S+\>/');
foreach my $line (@lines) {
  print $fh $line;
}
close $fh;

# Close $rh or do more stuff here
# ...

[download]

Finally, note the use of "| no-more" to safeguard against output longer than your (virtual) terminal size which would cause an interactive prompt. Use it always, just to be safe.

If you're not using a Juniper device, read the stuff about the loop and disregard everything else :o)

-- FloydATC

Time flies when you don't know what you're doing

In reply to Re: File operations by FloydATC
in thread File operations by Anonymous Monk

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