Re: Clocking Portion of Your Perl Code

An example -

#!/usr/bin/perl -w

use Benchmark;

my $start_time = new Benchmark;

$line++ while (<>);   # Count number of lines in the file(s)

my $end_time = new Benchmark;
my $difference = timediff($end_time, $start_time);

print ("Counted $line lines\n");
print ("It took ", timestr($difference), "\n");
[download]

Usage/Output:

[sk]% bench *.csv

Counted 900285 lines
It took  2 wallclock secs ( 1.88 usr +  0.27 sys =  2.15 CPU)
[download]

Comment on Re: Clocking Portion of Your Perl Code Select or Download Code

Replies are listed 'Best First'.
Re^2: Clocking Portion of Your Perl Code by Anonymous Monk on Jun 12, 2005 at 09:57 UTC
Hi, THanks for the reply. >It took 2 wallclock secs ( 1.88 usr + 0.27 sys = 2.15 CPU) What's the difference between these three: `wallclock usr sys` [download]	[reply] [d/l]
Re^3: Clocking Portion of Your Perl Code by kaif (Friar) on Jun 13, 2005 at 01:16 UTC
In short, the wallclock time elapsed is the real (actual) time that passed during the execution of your program. The CPU time is the time it took for the CPU to execute the program, taking into account the fact that your program may not be the only thing running at the moment, so that more or less this is independent of the load on your system. CPU time is further broken down into time used for system calls and time spent actually in your code. Using the time Command to Measure CPU Use, despite being a guide for AIX users, has a pretty good explanation as well.	[reply]