How to collect CPU values from WMI. #perl #win32 #wmi

This program will demonstrate how easy it is to obtain data from Windows Management Instrumentation (WMI), using a perl script. By analogy other information may be collected from WMI.

To obtain these data, I used the WMI Performance Counter class "Win32_PerfRawData_PerfOS_Processor" , which provides me the counters that measure aspects of processor(s) activity.

Since the data collected via WMI are percentages. I just needed to calculate the percentage of time used for each counter, depending on the time interval between measurements.

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1. use strict;  
2. use warnings;  
3.   
4. use Win32::OLE;  
5.   
6.   
7. my $interval = 1;  
8. my $key = 'Name';  
9. my @properties = qw(PercentIdleTime PercentProcessorTime PercentPrivilegedTime PercentUserTime PercentInterruptTime TimeStamp_Sys100NS);  
10.   
11. my $hash1 = {};  
12.   
13. my $wmi = Win32::OLE->GetObject("winmgmts://./root/cimv2")  
14.  or die "Failed to get object\n";  
15.   
16.   
17. my $list = $wmi->InstancesOf('Win32_PerfRawData_PerfOS_Processor')  
18.  or die "Failed to get instance object\n";  
19.   
20. my $v;   
21. foreach $v (in $list) {     
22.   map{$hash1->{$v->{$key}}->{$_}  = $v->{$_} }@properties;  
23. }  
24.    
25. while(sleep 1){  
26.   
27.  $list = $wmi->InstancesOf('Win32_PerfRawData_PerfOS_Processor')  
28.   or die "Failed to get instance object\n";  
29.    
30.  my $hash = {};  
31.  foreach $v (in $list) {     
32.   map{$hash->{$v->{$key}}->{$_}  = $v->{$_} }@properties;  
33.  }  
34.   
35.  my $cpu_time = sprintf("%.2f", (1 - get_value($hash1->{'_Total'}, $hash->{'_Total'}, 'PercentProcessorTime' )) * 100);  
36.  my $cpu_idle = sprintf("%.2f", 100-$cpu_time);  
37.  my $cpu_user = sprintf("%.2f", get_value($hash1->{'_Total'}, $hash->{'_Total'}, 'PercentUserTime' )* 100);  
38.  my $cpu_priv = sprintf("%.2f", get_value($hash1->{'_Total'}, $hash->{'_Total'}, 'PercentPrivilegedTime' )* 100);  
39.  my $cpu_int = sprintf("%.2f", get_value($hash1->{'_Total'}, $hash->{'_Total'}, 'PercentInterruptTime' )* 100);    
40.  printf "CPU Time %s %% , privileged %s %% , user %s %%, interrupt %s %%\n", $cpu_time,$cpu_priv,$cpu_user,$cpu_int;  
41.   
42.  $hash1 = $hash;  
43. }  
44.   
45.   
46. exit;  
47.   
48. sub get_value {  
49.  my $h1 = shift;  
50.  my $h2 = shift;  
51.  my $property = shift;  
52.  return (($h2->{$property} - $h1->{$property})/($h2->{'TimeStamp_Sys100NS'}-$h1->{'TimeStamp_Sys100NS'}));  
53. }  

use strict;
use warnings;

use Win32::OLE;


my $interval = 1;
my $key = 'Name';
my @properties = qw(PercentIdleTime PercentProcessorTime PercentPrivilegedTime PercentUserTime PercentInterruptTime TimeStamp_Sys100NS);

my $hash1 = {};

my $wmi = Win32::OLE->GetObject("winmgmts://./root/cimv2")
 or die "Failed to get object\n";


my $list = $wmi->InstancesOf('Win32_PerfRawData_PerfOS_Processor')
 or die "Failed to get instance object\n";

my $v; 
foreach $v (in $list) {   
  map{$hash1->{$v->{$key}}->{$_}  = $v->{$_} }@properties;
}
 
while(sleep 1){

 $list = $wmi->InstancesOf('Win32_PerfRawData_PerfOS_Processor')
  or die "Failed to get instance object\n";
 
 my $hash = {};
 foreach $v (in $list) {   
  map{$hash->{$v->{$key}}->{$_}  = $v->{$_} }@properties;
 }

 my $cpu_time = sprintf("%.2f", (1 - get_value($hash1->{'_Total'}, $hash->{'_Total'}, 'PercentProcessorTime' )) * 100);
 my $cpu_idle = sprintf("%.2f", 100-$cpu_time);
 my $cpu_user = sprintf("%.2f", get_value($hash1->{'_Total'}, $hash->{'_Total'}, 'PercentUserTime' )* 100);
 my $cpu_priv = sprintf("%.2f", get_value($hash1->{'_Total'}, $hash->{'_Total'}, 'PercentPrivilegedTime' )* 100);
 my $cpu_int = sprintf("%.2f", get_value($hash1->{'_Total'}, $hash->{'_Total'}, 'PercentInterruptTime' )* 100);  
 printf "CPU Time %s %% , privileged %s %% , user %s %%, interrupt %s %%\n", $cpu_time,$cpu_priv,$cpu_user,$cpu_int;

 $hash1 = $hash;
}


exit;

sub get_value {
 my $h1 = shift;
 my $h2 = shift;
 my $property = shift;
 return (($h2->{$property} - $h1->{$property})/($h2->{'TimeStamp_Sys100NS'}-$h1->{'TimeStamp_Sys100NS'}));
}

Output sample:

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1. CPU Time 2.03 % , privileged 1.96 % , user 0.00 %, interrupt 0.00 %  
2. CPU Time 1.87 % , privileged 1.96 % , user 0.00 %, interrupt 0.00 %  
3. CPU Time 2.16 % , privileged 1.96 % , user 0.00 %, interrupt 0.00 %  
4. CPU Time 1.76 % , privileged 1.96 % , user 0.00 %, interrupt 0.00 %  
5. CPU Time 2.19 % , privileged 1.96 % , user 0.00 %, interrupt 0.00 %  
6. CPU Time 1.77 % , privileged 1.96 % , user 0.00 %, interrupt 0.00 %  
7. CPU Time 1.98 % , privileged 1.96 % , user 0.00 %, interrupt 0.00 %  
8. CPU Time 1.93 % , privileged 1.96 % , user 0.00 %, interrupt 0.00 %  
9. CPU Time 2.08 % , privileged 1.96 % , user 0.00 %, interrupt 0.00 %  
10. CPU Time 2.84 % , privileged 2.94 % , user 0.00 %, interrupt 0.00 %  

CPU Time 2.03 % , privileged 1.96 % , user 0.00 %, interrupt 0.00 %
CPU Time 1.87 % , privileged 1.96 % , user 0.00 %, interrupt 0.00 %
CPU Time 2.16 % , privileged 1.96 % , user 0.00 %, interrupt 0.00 %
CPU Time 1.76 % , privileged 1.96 % , user 0.00 %, interrupt 0.00 %
CPU Time 2.19 % , privileged 1.96 % , user 0.00 %, interrupt 0.00 %
CPU Time 1.77 % , privileged 1.96 % , user 0.00 %, interrupt 0.00 %
CPU Time 1.98 % , privileged 1.96 % , user 0.00 %, interrupt 0.00 %
CPU Time 1.93 % , privileged 1.96 % , user 0.00 %, interrupt 0.00 %
CPU Time 2.08 % , privileged 1.96 % , user 0.00 %, interrupt 0.00 %
CPU Time 2.84 % , privileged 2.94 % , user 0.00 %, interrupt 0.00 %