7

Is this the proper way to define an include path for both *nix and Windows?

define( 'INCPATH', realpath( dirname( __FILE__ ) ) . '/' );

Note the trailing forward-slash I included above. Is the forward-slash for includes/requires the same for both OS's, as well?

EDIT (UPDATED WITH ANSWER):

From what I can gather, my code below is the proper way to universally define an include/require path for both *nix and Windows OS's. Feel free to correct anything in the comments below.

The thing that confused me were the many examples I saw showing replacement of back-slashes (\) into forward-slashes(/). Based on some of the answers below, this is unnecessary.

So the final correct code (for the purist) is:

define( 'INCPATH', realpath( dirname( __FILE__ ) ) . DIRECTORY_SEPARATOR );

That code produces the following results:

*nix: /path/to/the/file/

Windows: C:\Path To\the\file\

A brief explanation, working our way from the inside (__FILE__) out (realpath()):

FILE The full path and filename of the file. Always contains an absolute path with symlinks resolved.

dirname() The returned string is path with any trailing /component removed. Responsible for removing the filename.

realpath() Returns the canonicalized (normalized/standardized) absolute pathname on success. The resulting path will have no symbolic link, '/./' or '/../' components. I assume this is included for thoroughness because __FILE__ already resolves symlinks. Or maybe it's included to resolve relative paths? Either way, it seems to solidify our goal.

Jeff
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  • In Windows, you only need the leading C: if your current directory is on a device other than C. Thus, /www/file.php should work just fine on Windows. It would be nice if PHP could optionally interpret absolute pathnames as rooted at the DocumentRoot defined in the Apache configuration, but that might be too much to ask. – David Spector Sep 06 '18 at 19:36
  • I think you have to use the PHP function set_include_path or the Apache directive include_path instead of define to change the Include path. – David Spector Sep 06 '18 at 19:45

3 Answers3

8

Forward slashes will work for both OS's, and it's the way to go.

I couldn't find an absolute reference to this, but it's indicated in several places in the PHP manual, like here and here. And, it works for me, a Windows & Linux user.

Lastly, you may end up specifying mixed-paths on Windows, like c:\\apache\\htdocs\\myapp/index.php, and that all works fine.

Derek Illchuk
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  • @Derek, good info - thanks. I will assume my definition above works on both OS's. – Jeff Dec 24 '09 at 21:21
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    I often wonder why backslashes are still used, since it causes escape headaches and forward slash would work just as well. – Ether Dec 24 '09 at 21:30
  • I think the answer is that forward slashes do not work in all of the rest of Windows, just mostly in PHP. – David Spector Sep 06 '18 at 19:38
4

Alternatively you can use PHP's predefined constant DIRECTORY_SEPARATOR, which will give you the OS-specific directory delimiter. See http://www.php.net/manual/en/dir.constants.php also.

Decent Dabbler
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2

To many people's surprise, / works fine on Windows—and MSDOS. Within pathnames, it works even on OpenVMS.

However, if you are doing something within PHP for paths, an array would be a more convenient structure than a string.

$MYPATH = array ('.', '/usr/lib/', '/usr/share/lib');
wallyk
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