PHP Authentication using text file - php

Question

So i have fixed the problem with the loop by placing the ifelse statement outside the for loop. So when it is true it is working fine. However when FALSE i get the following error!
Notice: Undefined offset: 2 in webaddhidden.php on line 25 Invalid Login
I am new to PHP and am trying to make a simple login with a text file.
Error Message: if an incorrect username/password is entered :
Invalid LoginInvalid LoginInvalid LoginInvalid Login Notice: Undefined offset: 2 in webaddhidden.php on line 25 Invalid Login
and if the correct username/password the error is:
Invalid LoginMatch Found!
So it prints both the if and the ifelse statements.
Your help would be much appreciated.
Thanks!!!!
The code I am using is:
<?php
$username = $_POST['username'];
$password = $_POST['password'];
$matchFound = false;
$fileArray = array();
$myFile = fopen("customers.txt", 'r');
while(!feof($myFile) ) //reads all lines of text file
{
$fileArray[] = fgets($myFile);
}
fclose($myFile);
for($lineCounter = 0; $lineCounter < count($fileArray); $lineCounter++)
{
$exploadedLine = explode("\t",$fileArray[$lineCounter]);
if(trim($exploadedLine[2] == $username && trim($exploadedLine[3])
== $password))
{
echo 'Match Found!';
$matchFound = true;
break;
}
elseif($matchFound == false)
{
echo 'Invalid Login';
}
}
?>

Answer 1

This block of code is actioned as the file is searched - inside the loop.
elseif($matchFound == false)
{
echo 'Invalid Login';
}
It needs to be placed outside the loop.

Answer 2

Few things you can do to fix/improve your code:
You can use file() to directly read lines of text files into an array. http://www.php.net/function.file-get-contents
Make sure indexes of are set in exploded array using isset() function to avoid notices in case the text file is not formatted as expected. http://www.php.net/manual/en/function.isset.php
Move the logic block checking invalid login out of the loop so that it doesn't print invalid error message each time the loop finds a mismatch.
Try using the code below:
<?php
$username = $_POST['username'];
$password = $_POST['password'];
$matchFound = false;
$fileArray = file("customers.txt"); //reads all lines of text file
for ($lineCounter = 0; $lineCounter < count($fileArray); $lineCounter++) {
$exploadedLine = explode("\t", $fileArray[$lineCounter]);
if ((isset($exploadedLine[2]) && trim($exploadedLine[2]) == $username) &&
(isset($exploadedLine[3]) && trim($exploadedLine[3]) == $password)) {
echo 'Match Found!';
$matchFound = true;
break;
}
}
if ($matchFound === false) {
echo 'Invalid Login';
}
?>