That's better.

A few comments:

• Always check the result of a file open or I/O operation.
• You don't need to know the size of your file to use sysread. You can say how much sysread should read, and that function will return the number of bytes read, or 0 when it's finished.
• If you really need to know the file size, use a -s check.

Here is an example.

#!/usr/bin/perl
use warnings;
use strict;

my $filename = "stable.tar.gz"; # it's the latest Perl source code

die "filename not found\n" unless -f $filename;

my $size = -s $filename;

my $total_read = 0;

open F, "< $filename"
        or die "can't open $filename\n";

my $bufsize = 2_000_000;
my $buffer;

while ( my $read = sysread(F , $buffer , $bufsize,  ) )
{
    printf "Read %8u bytes\n", $read;
    # do something with $buffer
    $total_read += $read;
}

print "initial size: $size\n";
print "total read:   $total_read\n";
__END__
output:
Read  2000000 bytes
Read  2000000 bytes
Read  2000000 bytes
Read  2000000 bytes
Read  2000000 bytes
Read  2000000 bytes
Read   254916 bytes
initial size: 12254916
total read:   12254916
[download]

HTH

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