PHP random number generation, page jump, file reading and writing, file renaming, switch statement_PHP tutorial

num = rand(1,5);
witch($num){
case 1:
$fp1=fopen("f1.dat",'r');
$oname = fgets($fp1);
$nname = date("YmdHis");

rename($oname,$nname);
fclose($fp1);
unlink("f1.dat");
$fp1=fopen("f1.dat",'w');
fwrite($fp1,$nname);
fclose($fp1);

header("Location: ".$nname."/1.html");
exit;
break;
case 2:
$fp2=fopen("f2.dat",'r');
$oname = fgets($fp2);

$nname = date("YmdHis");
rename($oname,$nname);
fclose($fp2);
unlink("f2.dat");
$fp2=fopen("f2.dat",'w');
fwrite
($fp2,$nname);
fclose($fp2);
header("Location: ".$nname."/2.html");
exit;
break;
case 3:
$fp3=fopen
("f3.dat",'r');
$oname = fgets($fp3);
$nname = date("YmdHis");
rename($oname,$nname);
fclose($fp3);
unlink
("f3.dat");
$fp3=fopen("f3.dat",'w');
fwrite($fp3,$nname);
fclose($fp3);
header("Location: ".$nname."/3.html");

exit;
break;
case 4:
$fp4=fopen("f4.dat",'r');
$oname = fgets($fp4);
$nname = date("YmdHis");
rename
($oname,$nname);
fclose($fp4);
unlink("f4.dat");
$fp4=fopen("f4.dat",'w');
fwrite($fp4,$nname);
fclose($fp4);

header("Location: ".$nname."/4.html");
exit;
break;
case 5:
$fp5=fopen("f5.dat",'r');
$oname = fgets($fp5);

$nname = date("YmdHis");
rename($oname,$nname);
fclose($fp5);
unlink("f5.dat");
$fp5=fopen("f5.dat",'w');
fwrite
($fp5,$nname);
fclose($fp5);
header("Location: ".$nname."/5.html");
exit;
break;
default:
break;
}
?>