function randomint($max = 1) {
$m = 1000000;
return ((mt_rand(1,$m * $max)-1)/$m);
}
?>
$line_number = 0;
$fh = fopen('data.txt','r') or die($php_errormsg);
while (! feof($fh)) {
if ($s = fgets($fh)) {
$line_number++;
if (randomint($line_number) < 1) {
$line = $s;
}
}
}
fclose($fh) or die($php_errormsg);
?>