Alternate approach but leaving the complexities that would cause varying execution times for the tested script, foo_a.pl (that's left as the proverbial challenge for the OP). Note also the caveat at LN9 of the script immediately below:

#!/usr/bin/perl -w
use strict;

use Time::HiRes qw[ time ];

# OP: "I have a perl script that I need to run 1000 times and for each
+ run 
#      I need to store how much time it took to run... "
# using foo_a.pl, execute this from foo_a's dir
# Timings of foo_a.pl are NOT precise because they include the time 
# to execute the calculations here.

my $begin = time;
for my $arg( 1..1000 ) {
    my $start = time;
    system "perl foo_a.pl $arg";
    my $duration = (time - $start);
    print "\n\t\$arg: $arg, \t\$start: $start, \t\$duration: $duration
+\n";
    $start = time;
}

print "$begin" . time . "\n";
exit;

[download]

foo_a.pl, an (almost) empty script:

#! /usr/bin/perl -w
use strict;

#foo_a.pl

print "--foo_a.pl's marker inserted when run at LN11 in 1173964_a.pl: 
+";
exit;

[download]

And the output of D:\_Perl_\PMonks>D:\_Perl_\PMonks\1173964_a.pl > 1173964_a_OUT.pl on (Win7, AS 5.18), edited as noted:

--foo_a.pl's marker inserted when run at LN11 in 1173964_a.pl: 
    $arg: 1,     $start: 1476409956.16692,     $duration: 0.0165810585
+021973
--foo_a.pl's marker inserted when run at LN11 in 1173964_a.pl: 
    $arg: 2,     $start: 1476409956.18353,     $duration: 0.0134079456
+329346
--foo_a.pl's marker inserted when run at LN11 in 1173964_a.pl: 
    $arg: 3,     $start: 1476409956.19695,     $duration: 0.0137300491
+333008
--foo_a.pl's marker inserted when run at LN11 in 1173964_a.pl: 
    $arg: 4,     $start: 1476409956.2107,     $duration: 0.01424980163
+57422

# elided for brevity and henceforward, "marker inserted" lines deleted
+:

    $arg: 495,     $start: 1476409962.28221,     $duration: 0.01291704
+17785645
    $arg: 496,     $start: 1476409962.29514,     $duration: 0.01339387
+89367676
    $arg: 497,     $start: 1476409962.30855,     $duration: 0.01174592
+97180176
    $arg: 498,     $start: 1476409962.32031,     $duration: 0.01395082
+47375488
    $arg: 499,     $start: 1476409962.33427,     $duration: 0.01355600
+35705566
    $arg: 500,     $start: 1476409962.34784,     $duration: 0.01249790
+19165039
    $arg: 501,     $start: 1476409962.36035,     $duration: 0.01373386
+38305664
    $arg: 502,     $start: 1476409962.3741,     $duration: 0.012020826
+3397217
    $arg: 503,     $start: 1476409962.38613,     $duration: 0.01191496
+84906006
    $arg: 504,     $start: 1476409962.39807,     $duration: 0.01241683
+95996094
    $arg: 505,     $start: 1476409962.4105,     $duration: 0.012879133
+2244873

# another long stretch omitted...

    $arg: 995,     $start: 1476409968.50899,     $duration: 0.01135301
+58996582
    $arg: 996,     $start: 1476409968.52035,     $duration: 0.01180887
+22229004
    $arg: 997,     $start: 1476409968.53218,     $duration: 0.01137590
+4083252
    $arg: 998,     $start: 1476409968.54356,     $duration: 0.01149606
+70471191
    $arg: 999,     $start: 1476409968.55507,     $duration: 0.01226401
+32904053
    $arg: 1000,     $start: 1476409968.56735,     $duration: 0.0137550
+830841064

[download]

NB: initial "begin time": 1476409956.16692; time completed: 1476409968.58113 or roughly 12 seconds for 1000 iterations of foo_a.pl measured this way ... and yes, I see the command line is unnecessarily redundant... but so (perhaps) is this node.



If you didn't program your executable by toggling in binary, it wasn't really programming!

In reply to Re: Run a script multiple times and store the running time by ww
in thread Run a script multiple times and store the running time by Anonymous Monk

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