process table

teamassociated has asked for the wisdom of the Perl Monks concerning the following question:

Problem: All 12 processes are not being populated into hash.

Reason: unknown. Why dont I see the last 12 from tail -12?


use strict;
use warnings;

my (%prochash,@parray,@pids,$list,$pid,$time,$cpu,$user,$args);
$|=1;

push @parray, qx(/usr/bin/ps -ef -o pid,time,pcpu,user,args|/usr/bin/t
+ail -12);
print scalar @parray,"\n";
foreach (@parray) {
    $pid  = (split)[0];
    $time = (split)[1];
    $cpu  = (split)[2];
    $user = (split)[3];
    $args = (split)[4];
    $prochash{$cpu} = {
        'pid'  => $pid,
        'time' => $time,
        'user' => $user,
        'args' => $args,

    };

}
use Data::Dumper;
print Dumper \%prochash;

__DATA__
12
$VAR1 = {
          '0.1' => {
                     'pid' => '10485852',
                     'time' => '02:16:16',
                     'args' => '/opt/freeware/ossec/bin/ossec-syscheck
+d',
                     'user' => 'root'
                   },
          '0.0' => {
                     'pid' => '14876814',
                     'time' => '00:00:00',
                     'args' => '/bin/bsh',
                     'user' => 'root'
                   }
        };
[download]

Thank you!

Comment on process table Download Code

Replies are listed 'Best First'.
Re: process table by roboticus (Chancellor) on Dec 20, 2013 at 19:48 UTC
teamassociated: Because you have two CPUs, and a hash holds one item. So the last one read wins for each CPU. Try this to get a hash of arrays (HoA): `push @{$prochash{$cpu}}, { 'pid' => $pid, 'time' => $time, 'user' => $user, 'args' => $args, };` [download] Or if you want a hash of hashes (HoH), use the first level for the CPU and the second for the PID: `$prochash{$cpu}{$pid} = { 'pid' => $pid, 'time' => $time, 'user' => $user, 'args' => $args, };` [download] There are other ways to do it, too. You may want to review `perldoc perldsc` Update: Changed language a little to clarify. ...roboticus When your only tool is a hammer, all problems look like your thumb.	[reply] [d/l] [select]
Re: process table by aitap (Curate) on Dec 20, 2013 at 19:49 UTC
That's because you use the "%CPU" column as the hash key, yet its values are not unique, so newer values overwrite the older ones. For example, this is what I get on my machine: `$ ps -ef -o pid,time,pcpu,user,args\|/usr/bin/tail -12 \| perl -MData::D +umper -ne'$_{(split)[2]}++;END{print Dumper \%_}' $VAR1 = { '0.4' => 1, '%CPU' => 1, '0.0' => 7 };` [download] Use the PID column instead. _{Update: was a bit outrun by roboticus (++).}	[reply] [d/l]