Assigning output of unix command to a variable

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); 
[download]

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

Comment on Assigning output of unix command to a variable Download Code
Re: Assigning output of unix command to a variable by almut (Canon) on Dec 23, 2009 at 01:25 UTC
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 $_ \| awk -F Name: '{ print \$2 }'`; [download]	[reply] [d/l] [select]
Re^2: Assigning output of unix command to a variable by ksermas (Initiate) on Sep 04, 2012 at 18:53 UTC
Thank you very much. You were right. As soon as I eacaped the '$' it worked perfectly!!!	[reply]
Re: Assigning output of unix command to a variable by bichonfrise74 (Vicar) on Dec 23, 2009 at 01:34 UTC
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 $node;` [download]	[reply] [d/l]
Re: Assigning output of unix command to a variable by ikegami (Pope) on Dec 23, 2009 at 01:36 UTC
Is the only problem that you forgot to escape the `$` 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. )	[reply] [d/l] [select]


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Assigning output of unix command to a variable

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