Can you please explain what each line of code does to a CSV files.
print "Begin the program: \n";
open(IN,"$file") or die "can not open the inputfile\n";
my @lines = <IN>;
/^A(\d+)/ || next;
my $f="c:/Program Files/TIE Commerce/Crunchyroll/in_csv/$1.CRUsinglepo";
open OUT,">>$f" or die $!;