PHP - Cannot start even the most basic session

Question

Here is my code:

<?php 
session_start();

No other includes, spaces or anything. The entire file has two lines.

The output I get:

Warning: session_start(): Cannot send session cookie - headers already sent by (output started at C:\xampp\htdocs\webpage\test.php:1) in C:\xampp\htdocs\webpage\test.php on line 2

Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at C:\xampp\htdocs\webpage\test.php:1) in C:\xampp\htdocs\webpage\test.php on line 2

I am using Xampp. Any ideas?

EDIT: From php.ini

session.save_handler=files
session.save_path="C:\xampp\tmp" (which exists and is writable by everyone)

Put an ob_start() before session_start(). The correct way is search for what is being output before this call but this one also works — CarlosCarucce, Nov 03 '15 at 12:57
What @Fred-ii- said. Have a look [here](https://en.wikipedia.org/wiki/Byte_order_mark) for things related to BOM. — Andrei, Nov 03 '15 at 12:59
@Fred it seems it was encoding. Weird thing is I am am using PHPStorm. Shouldn;t the encoding always be UTF8? — Jacques, Nov 03 '15 at 13:03
@Jacques shouldn't really matter, could be ANSI, but when using UTF-8, there are 2 ways to save it. with or without BOM, you need without it. If UTF-8 is what you must use then use it without the BOM. — Funk Forty Niner, Nov 03 '15 at 13:04
@Jacques since there were other answers given, I decided to post one in order to close the question, should you want to mark it as solved. — Funk Forty Niner, Nov 03 '15 at 13:12
@Jacques I've made a few edits to my answer below. Reload it to see what was added. The question should be marked as solved. — Funk Forty Niner, Nov 03 '15 at 13:32

score 2 · Answer 1 · edited May 23 '17 at 11:44

As per my comment (asking what the encoding was), it's an encoding issue (as per what you said also).

If UTF-8 is the format you must use, then you need to save that file without the BOM (byte order mark).

It counts as output.

More on that can be found here:

https://en.wikipedia.org/wiki/Byte_order_mark

Read the following on Stack in regards to the differences between with and without BOM:

What's different between UTF-8 and UTF-8 without BOM?

"@Fred it seems it was encoding. Weird thing is I am am using PHPStorm. Shouldn;t the encoding always be UTF8? – Jacques"

Not always. Certain applications require a UTF-8 format be used (databases, accents on characters, etc.). You can use any format you want, just as long as it works for the way it is to be used.

If you don't need to use sessions, then don't add session_start();.

Here is an article on the W3C website that you can read:

http://www.w3.org/International/questions/qa-choosing-encodings

and one here on Stack:

Is there any reason not to use UTF-8, 16, etc. for everything?

and if you have time:

https://wordtothewise.com/2010/03/which-is-better-utf-8-or-iso/

You can further your research by using "why should I use utf-8?" as keywords in your favorite search engine.

score 1 · Answer 2 · answered Nov 03 '15 at 13:01

Check either session was started or not.

Recommended way for versions of PHP >= 5.4.0

if (session_status() == PHP_SESSION_NONE) {
    session_start();
}

Source: http://www.php.net/manual/en/function.session-status.php

For versions of PHP < 5.4.0

if(session_id() == '') {
    session_start();
}

score 0 · Answer 3 · edited Nov 03 '15 at 14:46

0

Add a line after the opening PHP tag:

<?php

ob_start(); //Add this!
session_start();

edited Nov 03 '15 at 14:46

Anders

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answered Nov 03 '15 at 13:22

ImBhavin95

1,403
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score 0 · Answer 4 · answered Nov 03 '15 at 13:29

Besides what others say, you can also enable output buffering in your php.ini. If you set for instance:

output_buffering = 4096

Then all your output will be buffered (up to 4k) before being sent to browser. This will prevent any accidental output to be sent before your session_start().

PHP - Cannot start even the most basic session

4 Answers4