PHP header('Location:') not working on server if tab or space is there in .php file

Question

I am using PHP 5.6.

Recently, I have moved my projects to a new server and since then I am facing a strange problem.

The redirects using php header('Location:some_url') is not working if there is a space or tab is there before opening of php tag (<?php) or after closing php tag (?>) into a php file on which user is being redirected. It returns blank page.

It happens in only files which contains pure php codes, no javascript, jquery, or html there in the file.

Sometimes the issues is like, suppose there is a file a.php e.g.

<?php

// some statements here and end of php tag

?>

<?php

// opening of php tag and statements here and end of php tag

?>

Now, technically it should work but it is not working unless I remove the closing and opening php tag from the middle of the file. There are several files are there containing such a codes. Please let me know how to fix it?

yes, you cannot do redirection if something prints before PHP. — Thamaraiselvam, Mar 15 '18 at 06:03
Then how it was working on my old server? Is there any extension or setting that I can bypass it? — Dev, Mar 15 '18 at 06:04
From php.net, Remember that header() must be called before any actual output is sent, either by normal HTML tags, blank lines in a file, or from PHP. It is a very common error to read code with include, or require, functions, or another file access function, and have spaces or empty lines that are output before header() is called. The same problem exists when using a single PHP/HTML file. — Rendi Wahyudi Muliawan, Mar 15 '18 at 06:04
@Dev this may help you https://stackoverflow.com/a/29547155/2975952 — Thamaraiselvam, Mar 15 '18 at 06:06
Thanks @Thamaraiselvam. I will mark this question as duplicate. — Dev, Mar 15 '18 at 06:10

score 0 · Answer 1 · answered Mar 15 '18 at 06:09

Either remove the spaces or enable output buffering. This happens because PHP prints everything not within <?php ?> tags literally. To do that, it has to first send all the headers, and then switch to sending body. But the way HTTP protocol is built, headers must always come before the body, so php can't go back and send more headers after the body has started.

PHP header('Location:') not working on server if tab or space is there in .php file

1 Answers1