use warnings;
use strict;

my $matching_line_loc = 0;
my $matching_line = '';

open (TEST_FILE, "<test.dat")
	or die "Couldn't open test.dat: $!\n";
while (<TEST_FILE>) {
	if (/333/) { #remember matching line and line number
		$matching_line = $_;
		$matching_line_loc = $.;
		last;
	}
}
close TEST_FILE;

if ($matching_line) { #don't bother with rest if no match!
	open (TEST_FILE, "<test.dat")
		or die "Couldn't open test.dat: $!\n";
	open (TMP_FILE, ">test.tmp")
		or die "Couldn't open/create test.tmp: $!\n";
	
	#print the matching line first
	print TMP_FILE $matching_line;
	#print everything BUT the matching line
	while (<TEST_FILE>) {
		print TMP_FILE $_ unless $. == $matching_line_loc;
	}
	close TMP_FILE;
	close TEST_FILE;

	#remove original file and rename rearranged file
	unlink "test.dat" or die "couldn't remove test.dat: $!\n";
	rename "test.tmp", "test.dat";
}