Now, I won’t bore you with the actual details of how I came across this – lets just skip to the explanation and example:
First, even when it makes ’sense’, you should not be using relative paths in your command line PHP scripts. I am so used to writing web PHP that I fell into this bad habit.
Show Me Why dirname() is your hero
Imagine a directory structure on windows like this:
C:\DEVELOPMENT\local>dir
Volume in drive C has no label.
Volume Serial Number is 1122-45E1
Directory of C:\DEVELOPMENT\local
04/23/2009 08:40 PM .
04/23/2009 08:40 PM ..
04/23/2009 08:37 PM includes
04/23/2009 08:40 PM testdirname
0 File(s) 0 bytes
4 Dir(s) 67,484,995,584 bytes free
We have two files:
testdirname/script.php
1
2
| require_once '../includes/include.php';
print "I've done ran, ya'll."; |
includes/include.php
1
| print "I'm an include!\n"; |
Now, let’s run the script as it is:
C:\DEVELOPMENT\local\testdirname>php script.php
I'm an include!
I've done ran, ya'll.
Not too bad – but note how we’re actually in the script.php’s working directory. What if we wanted to run it in a different directory?
C:\DEVELOPMENT\local>php testdirname\script.php
Warning: require_once(../includes/include.php): failed to open stream: No such file or directory in C:\DEVELOPMENT\local\testdirname\script.php on line 2
Well this makes sense because I programmed with that relative path.
Instead, change the require line in script.php to this:
1
| require_once dirname(__FILE__) . '/../includes/include.php'; |
This way, it always gets the full directory of the file itself (__FILE__ constant) – and THEN you can path to the file any which way you’d like.
Let’s check the output:
C:\DEVELOPMENT\local>php testdirname\script.php
I'm an include!
I've done ran, ya'll.
Yep – I KNOW – Simple. Its embarrassing to say it bit me – but it did 
