Assigning output of unix command to a variable

[ksermas]

Is there a way to send the output of a unix command to a variable in Perl? I'm trying to have a while loop read in input, assign it to a variable and then have that variable be the input for the unix command. This is what I have:

#!/usr/bin/perl -w open(LIST, "list"); 
 while(<LIST>) {

  @nodes=(<LIST>); 
  chomp; 
  my $nodename=`nslookup $_ | awk -F Name: '{ print $2 }'`;  
  print $nodename; } 
  
close(LIST);

When I run it, it can't get past the '|' in the nslookup command. Thanks to all who can help.

[almut]

Not really sure why it doesn't get past the '|' (works fine here), but what looks suspicious is the @nodes=(<LIST>); as this reads everything from the second line onwards into an array which you never use in the loop. As a result, there would only be one call to nslookup with $_ holding the first line of the input file. Not sure if that's intended.

Independently of that, you probably want to escape the $2 in the awk command, because backticks do interpolate variables... i.e.

my $nodename=`nslookup $_ | awk -F Name: '{ print \$2 }'`;

[ksermas]

Thank you very much. You were right. As soon as I eacaped the '$' it worked perfectly!!!

[bichonfrise74]

What do you mean by "can't get past the '|' in the nslookup"? Consider this example.

#!/usr/bin/perl

use strict;

my $node = qx( nslookup www.perlmonks.org | 
               awk -F Name: '{ print \$2 }' );
print $node;

[ikegami]

Is the only problem that you forgot to escape the $ in $2? $2 is getting interpolated just like $_.

( Oops, I must have had this node open a while since almut already said this a while ago, and she caught a problem I missed. )