What are all the ways to traverse directory trees?

Question

How do you traverse a directory tree in your favorite language?

What do you need to know to traverse a directory tree in different operating systems? On different f

Answer 1

In Java:

Recursion is useful here. Following is a Java code snippet that's been all over the Internet for ages. Not sure who deserves the credit for it.

// Process all files and directories under dir

    public static void visitAllDirsAndFiles(File dir) {

        process(dir);  //do something useful with the file or dir

        if (dir.isDirectory()) {
            String[] children = dir.list();
            for (int i=0; i