[perl] Reading output from a system cmd

onyxdragun · 04-30-2012, 01:50 PM

This is what I have

Code:

#!/usr/bin/perl
system "cat /proc/net/arp  | awk 'NR > 1 {print \$4}'"

Which reads the MAC addresses from the ARP table.

What I would like to do is be able to pass that into an array so I can foreach() it to process the results line by line.

Now, print outputs to the screen. I thought about assigning the call to @macs or something but I don't think that is totally correct.
I was using exec before, but read that exec does not return, where as system will return.

So, am I on the right track or am I completely lost? lol

Sergei Steshenko · 04-30-2012, 01:54 PM

Quote:

Originally Posted by onyxdragun

This is what I have

Code:

#!/usr/bin/perl
system "cat /proc/net/arp  | awk 'NR > 1 {print \$4}'"

Which reads the MAC addresses from the ARP table.

What I would like to do is be able to pass that into an array so I can foreach() it to process the results line by line.

Now, print outputs to the screen. I thought about assigning the call to @macs or something but I don't think that is totally correct.
I was using exec before, but read that exec does not return, where as system will return.

So, am I on the right track or am I completely lost? lol

Start learning Perl properly. You do not need 'awk' if you write in Perl.

Regarding your particular question - look up 'perl backticks'.

Learn from http://perldoc.perl.org/ - see in the left column 'Manual' -> Overview ( http://perldoc.perl.org/index-overview.html ) and so forth.