Processing Time

Why does the following script take so many cycles to complete?

The document it is sifting through is 20590 lines long and each line consists of the following, or a variation thereof; "10160354001 ALGIERS ALGERIA 36.70 3.60 290"

I am trying to make a database to match the first number to the last 3.

The actual program is however taking several seconds per line.

Script:

#! /usr/bin/perl

$path = shift(@ARGV);

open COORDS, $path or die "Couldn't open file\n";

my %coords = {};

foreach $line (<COORDS>){
    $stat = substr $line,0,11;
    @coords = grep(($_!=undef),split(/ /,substr $line,42));
    $coords[$stat]=@coords;
}

print $coords['10160354001'];

close(COORDS);

Solution

$coords['10160354001'] = ... is an assignment to an array element, and a large one at that. This statement will cause Perl to allocate an array with room for at least 10160354002 elements.

You meant to use a hash:

$coords{$stat} = "@coords";
...
print $coords{'10160354001'};

use strict and use warnings would have alerted you to this and other problems with your code.