I was messing around trying to get the offset of a string within a file with this code:

#!/usr/bin/perl

use strict;
use warnings;

open my $fh, '<', shift or die "Error: $!";

my $chunk;
my $find = 'regf';
while (my $bytes = read $fh, $chunk, 1024)
{
    unless ((my $idx = index $chunk, $find) < 0)
    {
        printf "Found %s at offset %x\n", $find, tell $fh + $idx - $by
+tes;
    }
}

[download]

There is a bug in my code at tell $fh + $idx which is fixed by tell($fh) + $idx. I understand that part. What I don't understand is why it segfaults? What is the result of adding an integer to a filehandle?

This is perl, v5.10.0 built for i486-linux-gnu-thread-multi

 

Update: fixed logic to give actual offset

print pack("A25",pack("V*",map{1919242272+$_}(34481450,-49737472,6228,0,-285028276,6979,-1380265972)))

In reply to Perl segfaults: Why? by bv

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