I managed to figure out at least one way to use Benchmark, will wonders never cease. :)
(Don't know if I have used it in the best possible way, though.)
Result of running the script shown below: 
Benchmark: timing 30 iterations of REGEXP, SPLIT...
    REGEXP: 10 wallclock secs ( 9.73 usr +  0.25 sys =  9.98 CPU)
     SPLIT: 47 wallclock secs (47.20 usr +  0.28 sys = 47.48 CPU)

[download]

The script didn't pass muster with "-w" when I was trying to print matching lines to "NUL" (file handle hadn't been opened). I changed it simply to count matching lines. "-w" is now happy. (Note to self: something else for later study: how to print only to "NUL" w/out complaint from "-w".)

The source (CSV) file is 13,576 lines long (1,703,397 bytes). Each record has 12 fields; the average length per record is 124 characters. The task is to print only lines whose fourth fields contain "MAPI". 

use strict;
use Benchmark;

timethese( 30, {
      REGEXP => 'UsingRegExp',
      SPLIT  => 'UsingSplit'
    }
);

sub UsingRegExp {
    my $file = 'r:\csv\test.csv';
    my $field;
    my $count = 0;
    open FH, $file or die "\n $file: $!\n";
    while ( <FH> ) {
        #  WANT 4TH FIELD. (NOTE: SOME FIELDS _MIGHT_ BE EMPTY.)
        ($field) = /^[^,]+,[^,]*,[^,]*,\s*([^,]+)\s*,/;
        $count++ if lc($field) eq "mapi";  #  IGNORE CASE
    }
    close FH or die "\n $file: $!\n";
}

sub UsingSplit {
    my $file = 'r:\csv\test.csv';
    my @record;
    my $count = 0;
    open FH, $file or die "\n $file: $!\n";
    while ( <FH> ) {
        @record = split /\s*,\s*/;
        $count++ if lc($record[3]) eq "mapi";  #  IGNORE CASE
    }
    close FH or die "\n $file: $!\n";
}

[download]

In reply to RE: RE: From one beginner to others . . . by greenhorn
in thread From one beginner to others . . . by greenhorn

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