Question with fopen() and mkdir()

[ghop2003]

I'm trying to create a simple CMS for people to contribute to my site. I know I need to use fopen() or mkdir() or possibly both. What I'm confused about is what they exactly do. I know to use something like $fh = fopen($filename, 'w') to open a file to write to. And, I know it creates the file if it doesn't exist. I think this is the correct way to use mkdir: mkdir("path/to/dir", 0777).

What I want to know is if fopen can actually create the directory or work in a directory different from where the file is located? For example, I have create.php (which has fopen) in /path/to/dir1 and I want to create the file in /path/to/dir2. If that path doesn't exist, will fopen() create it or do I have to use mkdir() to create it? Can I write to that directory after it is created using fopen()? I don't know if I made any sense here, but if I did, could someone help me?

[wildteen88]

fopen can only create files it cannot create folders. However mkdir attempts to create a directory.