可以说您的文本文件看起来像这样:

Lets say your text file looks something like this:

pete|petepass|pete@somesite.com|Pete Enterprizes
john|johnpass|john@somedomain.com|John Corporation

您的代码可以读取如下内容:

Your code can read something like this:

$userN = $_POST['user-name'];
$passW = $_POST['pass-word'];
$userlist = file ('users.txt');

$email = "";
$company = "";

$success = false;
foreach ($userlist as $user) {
    $user_details = explode('|', $user);
    if ($user_details[0] == $userN && $user_details[1] == $passW) {
        $success = true;
        $email = $user_details[2];
        $company = $user_details[3];
        break;
    }
}

if ($success) {
    echo "<br> Hi $userN you have been logged in. <br>";
} else {
    echo "<br> You have entered the wrong username or password. Please try again. <br>";
}