Good afternoon (in my time zone), fellow seekers. I am a complete novitiate here, this is my first post, so although I have read the guidelines, forgive me if in my ignorance I transgress in any way. I do have a few years' self-taught experience in Perl.

I am having a problem working with a large file under Perl 5.6.1, build MSWin32-x86-multi-thread, under Windows XP. In addition to Googling for an answer, I have also read How can I process large files efficiently? in the Questions and Answers, but it was not sufficient to solve my problem. I am already processing the file line by line (I think!).

There was a second suggestion there to use Tie::File. I tried this and don't seem to have it installed. Of course I can install it, but I'm wondering if there is a more obvious problem with what I'm doing. I'm not sure why I would need to use Tie::File if there is a way to just process the file line by line other than what I'm already doing.

Here is my code (stripped down to essentials, as the guidelines suggest, but which I had already done anyway): 

use strict;
use warnings;
open IN, "test.txt" or die "Could not open 'test.txt'\n";
for(<IN>) {      
   # do nothing
}
close IN;

[download]
The output is simply "Out of memory!" after the hard drive runs for about 2 minutes. The file is about 42 MB. What in this program could be gobbling up memory? Is this not the standard way to process a file line by line?

Lastly, it just occurred to me to see if maybe the newlines in the file were not standard DOS newlines (CR/LF), but they are. So that ain't it.

In reply to Large file problem by JohnBrook

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