Get an array of paths to available CD-ROM drives.
The dirs returned are platform-dependent ("D:\" on Win32, "/cdrom" or whatnot on Unix). Dirs are only returned if there is a disc ready and accessible in the drive. So if you've got two drives (D: and E:), and only E: has a disc in it, then that's all you get. If the user inserts a disc in D: and you call this function again, you get both drives. If, on a Unix box, the user unmounts a disc and remounts it elsewhere, the next call to this function will reflect that change.
This function refers to "CD-ROM" media, but it really means "inserted disc media," such as DVD-ROM, HD-DVD, CDRW, and Blu-Ray discs. It looks for filesystems, and as such won't report an audio CD, unless there's a mounted filesystem track on it.
This call may block while drives spin up. Be forewarned.