PHP_SELF vs PATH_INFO vs SCRIPT_NAME vs REQUEST_URI

Question

Hi All,

I am building a PHP app in CodeIgniter. CI sends all requests to the main controller, /index.php.

However, I don't like to see the index.php in the URL, so I've used mod_rewrite, as per the CI documentation.

The rule is as follows:

RewriteEngine on
RewriteCond $1 !^(images|inc|favicon\.ico|index\.php|robots\.txt)
RewriteRule ^(.*)$ /index.php/$1 [L]

So for example,

http://www.example.com/faq/whatever

will route to

http://www.example.com/index.php/faq/whatever

I need a reliable way for a script to know what it's address is, so it will know what to do with the navigation.

Normally, I would just check php_self, but in this case it's always index.php. I can get it from REQUEST_URI, PATH_INFO, etc, but trying to decide which will be most reliable.

Does anyone know, or know where to find, the real difference between PHP_SELF, PATH_INFO, SCRIPT_NAME, and REQUEST_URI?

Thanks!

Answer 1

Personally I use the $REQUEST_URI as it references the URI entered and not the location on the server's disc.

Answer 2

You may want to look into the URI Class and make use of $this->uri->uri_string()

Returns a string with the complete URI.

For example, if this is your full URL:

http://example.com/index.php/news/local/345

The function would return this:

/news/local/345

Or you could make use of the segments to drill down specific areas without having to come up with parsing/regex values

Answer 3

The PHP documentation can tell you the difference:

'PHP_SELF'

The filename of the currently executing script, relative to the document root. For instance, $_SERVER['PHP_SELF'] in a script at the address http://example.com/test.php/foo.bar would be /test.php/foo.bar. The __FILE__ constant contains the full path and filename of the current (i.e. included) file. If PHP is running as a command-line processor this variable contains the script name since PHP 4.3.0. Previously it was not available.

'SCRIPT_NAME'

Contains the current script's path. This is useful for pages which need to point to themselves. The __FILE__ constant contains the full path and filename of the current (i.e. included) file.

'REQUEST_URI'

The URI which was given in order to access this page; for instance, '/index.html'.

PATH_INFO doesn't seem to be documented...

Answer 4

Some practical examples of the differences between theese variables:
Example 1. PHP_SELF is different from SCRIPT_NAME only when requested url is in form:
http://example.com/test.php/foo/bar

[PHP_SELF] => /test.php/foo/bar
[SCRIPT_NAME] => /test.php/

(this seems to be the only case when PATH_INFO contains sensible information [PATH_INFO] => /foo/bar) Note: this used to be different in some older PHP versions (<= 5.0 ?).

Example 2. REQUEST_URI is different from SCRIPT_NAME when a non-empty query string is entered:
http://example.com/test.php?foo=bar

[SCRIPT_NAME] => /test.php
[REQUEST_URI] => /test.php?foo=bar

Example 3. REQUEST_URI is different from SCRIPT_NAME when server-side redirecton is in effect (for example mod_rewrite on apache):

http://example.com/test.php

[REQUEST_URI] => /test.php [SCRIPT_NAME] => /test2.php

Example 4. REQUEST_URI is different from SCRIPT_NAME when handling HTTP errors with scripts.
Using apache directive ErrorDocument 404 /404error.php
http://example.com/test.php

[REQUEST\_URI] => /test.php
[SCRIPT\_NAME] => /404error.php

On IIS server using custom error pages
http://example.com/test.php

[SCRIPT\_NAME] => /404error.php
[REQUEST\_URI] => /404error.php?404;http://example.com/test.php

Answer 5

Backup a second, you've taken the wrong approach to begin with. Why not just do this

RewriteEngine on RewriteCond $1 !^(images|inc|favicon.ico|index.php|robots.txt) RewriteRule ^(.*)$ /index.php?url=$1 [L]

instead? Then grab it with $_GET['url'];