YA: Simple Username/Password From File

<?php
// http://answers.yahoo.com/question/index?qid=20110906181257AAl7Fre
$user = strtolower( $_POST['user'] );
$pass = $_POST['pass'];

$lines = file('/assets/people.txt');
foreach($lines as $line){
    $parts = explode(':',$line);
    if($parts[0] == $user && $parts[1] == $pass){
        // Username & Password Combination is all good.
        echo 'That is a Good Username and Password Combo';
    }else{
        // Invalid Username/Password Combination
        echo 'Invalid Username/Password Combo';
    }
}

// This will work fine for a small number of entries, but for a larger list of people, this
// approach would be very taxing on your system.

/*             ALTERNATIVE APPROACH


$user = strtolower( $_POST['user'] );
$pass = $_POST['pass'];
$combo = $user . ':' . $pass . PHP_EOL;
$list = file_get_contents( '/assets/people.txt');
if(strpos($list,$combo) !== false){
    // Username & Password Combination is all good.
    echo 'That is a Good Username and Password Combo';
}else{
    // Invalid Username/Password Combination
    echo 'Invalid Username/Password Combo';
}


*/

?>