It sure can. Maybe looking at an excerpt of the setup.php of php-fusion will help you:

 Code:
if ($step == "1") {
	$db_host = stripinput($_POST['db_host']);
	$db_user = stripinput($_POST['db_user']);
	$db_pass = stripinput($_POST['db_pass']);
	$db_name = stripinput($_POST['db_name']);
	$db_prefix = stripinput($_POST['db_prefix']);
	$config = "<?php
// database settings
"."$"."db_host="."\"".$_POST['db_host']."\"".";
"."$"."db_user="."\"".$_POST['db_user']."\"".";
"."$"."db_pass="."\"".$_POST['db_pass']."\"".";
"."$"."db_name="."\"".$_POST['db_name']."\"".";
"."$"."db_prefix="."\"".$_POST['db_prefix']."\"".";
define("."\""."DB_PREFIX"."\"".", "."\"".$_POST['db_prefix']."\"".");
?>";
	$temp = fopen("config.php","w");
	if (!fwrite($temp, $config)) {
		echo $locale['430']."\n</td></tr>\n</table>\n";
		fclose($temp);
		exit;
	}
	fclose($temp);


Always learn from history, to be sure you make the same mistakes again...