#!/usr/bin/perl 

#$fname = $ARGV[0];
#$num = $ARGV[1];
#$prefix = $ARGV[2];
#$suffix = $ARGV[3];

$fname = shift;
$num = shift;
$prefix = shift;
$suffix = shift;

$nmsgs = 0;
$filenum = 0;
$ofile = $prefix . sprintf("%04d",$filenum) . $suffix;
open(OFILE,">" . $ofile);
open(INFILE,"<" . $fname);
while (<INFILE>) {
	if(/^From /){
		$nmsgs = $nmsgs + 1;
		if ($nmsgs > $num) {
			$filenum = $filenum + 1;
			$ofile = $prefix . sprintf("%04d",$filenum) . $suffix;
			close OFILE;
			open(OFILE,">" . $ofile);
			$nmsgs = 0;
			}
		}
	print OFILE $_;
	}
close OFILE;
close INFILE;