Hi all,
I wrote a script to update a binary data file. The file is a 2048x2048
unsigned-short array encoded in little-endian + 8K header. All values should be
even. However, there are some data corrupted with odd values. The task is to
set all odd numbers to 1.
I wrote a simple script which did the job, but it was too slow. It took over 40
seconds on my 5 year old PC. I wonder if there is better way to make it run
faster.
Thanks for help.
-Eugene
#### code snippet #############
use strict;
use warnings;
my $header;
my $header_size=8*1024;
my $body;
my $body_size=2048*2048*2;
my $image=$ARGV[0];
open(FH, "+<$image") or die "\nCan not open $image for updating: $!\n";
read(FH, $header, $header_size) == $header_size or print "\nshort read: $!\n";
read(FH, $body, $body_size) == $body_size or print "\nshort read: $!\n";
my $body_new;
my $p;
foreach $p (unpack("S*",$body)) {
if ($p&1) {$p=1};
$body_new=$body_new.pack("S",$p); # packing is slow ~40 seconds
}
seek FH, 0, 0;
print FH $header, $body_new;
close(FH);
_______________________________________________
Perl-Win32-Users mailing list
[email protected]
To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs
