Creating a Process Table hash in Perl

I came across a situation where I needed to access the process table in Perl. The problem that i found was that the best accessor Proc::ProcessTable only retrieved an array. Since it seems fairly senseless to keep looping over an array to find the exact process id that I want, you may want to turn it into a hash.

use strict;
use warnings;
use Proc::ProcessTable;

 # Create a new process table object
 my ($pt) = new Proc::ProcessTable;

 # Initialize your process table hash
 my (%pt_hash);

 # Get the fields that your architecture supports
 my (@fields) = $pt->fields;

 # Outer loop for each process id
 foreach my $proc ( @{$pt->table} ) {
    # Inner loop for each field within the process id
    for my $field (@fields) {
       # Add the field to the hash
       $pt_hash{$proc->pid}{$field} = $proc->$field();
    }
 }

It’s just as simple as that. If you want to be sure that its in there. At the end of the file add these two lines for proof:

use Data::Dumper;
print Dumper \%pt_hash;

The hash is organized with the keys being the process ids. There is another hash underneath it with all the fields as hash keys.

Posted in Perl. Tags: , . 1 Comment »
  • http://georgepalli.myopenid.com/ georgepalli

    I prefer this

    foreach my $proc ( @{$pt->table} )
    {
    $pt_hash{$proc->pid} = $proc;
    }

    Either way – you access the elements by

    $pt_hash->{$pid}->{$field}

    And you don't need to initialize @fields