The main time consumption of your processing is in the file IO, ie. (as you indicate) the line-by-line parsing, plus writing & generating CRC on an external file;
Is this necessary? Couldn't you just read the transactions one-by-one from the file, and run the CRC-calculation on each XML-trans in memory ?? -- As in (untested) :
#!/usr/bin/perl -w
use strict;
use warnings;
use String::CRC32; ### for instance
my $XmlData = <<XML_DATA;
<Transaction>
<MessageCode>100</MessageCode>
<ToAccountNo>12989898900</ToAccountNo>
</Transaction>
<Transaction>
<MessageCode>200</MessageCode>
<ToAccountNo>24536485582</ToAccountNo>
</Transaction>
XML_DATA
open my $XmlFile, '<', \$XmlData or die "Can't open XML file: $!";
$/ = "</Transaction>"; ### one trans at-a-time
while ( <$XmlFile> ) {
my $crc = crc32($_);
### & do whatever needs TBD with the $crc ...
}
Allan Dystrup