mkdir problem PHP

Warning: mkdir() [function.mkdir]: No such file or directory in

I keep getting this annoying message when trying to create new directories. my function is

mkdir("../".$a."/".$b);

$a = an existing filepath
$b = new folder i wis开发者_StackOverflow社区h to create

function is executed from another directory: my structure looks like this:

/htroot/site/c/ <- where im executing the function
/htroot/site/a/b <- where i wish to create the directories.

if i execute the following, it creates the desired effect but in the same directory as the function.

mkdir($a."/".$b);

HI ALL THANKS FOR THE HOT RESPONSES

C:\wamp\www\book\admin\import //is my __DIR__ for that script
C:\wamp\www\book\admin\property // already exists

C:\wamp\www\book\admin\property\name // want i want end result

Depending on how your function is included, the PWD could be anywhere. You're best to use an absolute path.

You can also grab the current script's directory using __DIR__ (v5.3+) or dirname(__FILE__)

For example

// use realpath to resolve any symbolic links
$newDir = realpath(__DIR__ . '/../' . $a) . '/' . $b;
mkdir($newDir);

See realpath()

Whatever "../$a" is, there's no such directory, however much you want there to be. Maybe there's a symlink, and .. isn't the directory you think it is.