PHP Check if user is logged in with a function - php

Question

I'm working on a website and the index page checks if the user is logged in or not with this piece of code:
if (!$_SESSION['login'] && $_SESSION['login'] == "") {
include_once($_SERVER['DOCUMENT_ROOT'] . "/login/");
} elseif ($_SESSION['login'] == 1) {
include_once($_SERVER['DOCUMENT_ROOT'] . "/main/");
}
But I want it to look cleaner, then I started wondering if was possible to achieve something like this with a function:
checklogin($_SESSION['login']);
I don't have much experience with functions, so i'm sorry if my question looks stupid, so thanks in advance.

Answer 1

Try this
if(check_login()) {
echo 'You are in!';
} else {
header('Location: login.php');
exit;
}
function check_login () {
if(isset($_SESSION['login'] && $_SESSION['login'] != '') {
return true;
} else {
false;
}
}

Answer 2

Just use empty:
if ( empty($_SESSION['login']) ) {
include_once($_SERVER['DOCUMENT_ROOT'] . "/login/");
} else {
include_once($_SERVER['DOCUMENT_ROOT'] . "/main/");
}
Or condense it:
include_once $_SERVER['DOCUMENT_ROOT'].(empty($_SESSION['login']) ? "/login/" : "/main/");

Answer 3

There is what you need:
function userCheck()
{
return (isSet($_SESSION['login']) && $_SESSION['login']);
}
if(userCheck())
include_once($_SERVER['DOCUMENT_ROOT'] . "/main/");
else
include_once($_SERVER['DOCUMENT_ROOT'] . "/login/");

Answer 4

Disregarding the fact of whether or not your approach makes sense, I think this would do what you expect:
function checklogin($login){
if (!$login && $login == "") {
include_once($_SERVER['DOCUMENT_ROOT'] . "/path/");
}
}
// **** call to the function
checklogin($_SESSION['login']);
// ****

Answer 5

You can use this function:
function checklogin() {
return (isset($_SESSION['login'])) ? true : false;
}
then on pages you want to check whether the user is logged in or not, you can:
if(checklogin() === true){
//here you would put what you want to do if the user is logged in
} else {
//this would be executed if user isn't logged in
header('Location: protected.php');
exit();
//the above would redirect the user
}