通过管理页面创建新的登录帐户 - 将表格数据保存到文本文件

Question

As you can probably guess, I am new to learning PHP and have an assignment to create a page where new user accounts can be created by entering the username and password into form fields, which then needs to be saved in a text document.

I have spent hours trying to figure this out and have tried what I have seen suggested on other questions. As I mentioned previously, I am very new to this and need to keep things basic.

<?php

if ($_SERVER["REQUEST_METHOD"] == "POST")
{
    $newUsername = trim(htmlspecialchars($_POST["newuser"]));
    $newPassword = trim(htmlspecialchars($_POST["newpwd"]));
    $file = "user_accounts.txt";

    $openfile = fopen($file, "a") or die("Unable to open file");

    if($newUsername || $newPassword == ""){
        echo '<script language="javascript">';
        echo 'alert("Error: Please complete all fields")';
        echo '</script>';}

    else{
        fwrite ($openfile, "$newUsername 
 $newPassword 
");
        fclose($openfile);}

}
?>

And here is my form code:

<form action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>" method="post">        
    Username: <input type="text" name="user"><br> 
    Password: <input type="password" name="pwd"><br> 
    <input type="submit"> 
</form>

Answer 1

The problem with your code is this:

if($newUsername || $newPassword == "") is missing == "" for $newUsername

Plus, your input form element names don't match.

$_POST["newuser"] with name="user" does not match.

$_POST["newpwd"] and name="pwd" does not match.

Tested:

<?php

if ($_SERVER["REQUEST_METHOD"] == "POST")
{
    $newUsername = trim(htmlspecialchars($_POST["newuser"]));
    $newPassword = trim(htmlspecialchars($_POST["newpwd"]));
    $file = "user_accounts.txt";

    $openfile = fopen($file, "a") or die("Unable to open file");

    if($newUsername == "" || $newPassword == ""){
        echo '<script language="javascript">';
        echo 'alert("Error: Please complete all fields")';
        echo '</script>';}

    else{
        fwrite ($openfile, "$newUsername 
 $newPassword 
");
        fclose($openfile);}

}
?>

<form action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>" method="post">        
    Username: <input type="text" name="newuser"><br> 
    Password: <input type="password" name="newpwd"><br> 
    <input type="submit"> 
</form>

---

Footnotes:

I suggest you change this line:

fwrite ($openfile, "$newUsername 
 $newPassword 
");

to

fwrite ($openfile, "$newUsername
$newPassword 
");

because it is adding a space (when testing) at the end of the user name and at the beginning (and at the end) of each password in the file itself, and this could have consequences in regards to character matching.

fwrite ($openfile, "$newUsername 
 $newPassword 
");
                                ^               ^

Another thing is, using this type of system is considered unsafe unless you are properly hiding it outside of the public realm and/or using .htaccess

Using a DB is safer.