Specifications

FIGURE 16.3

The directory listing shows all the files in the chosen directory, including the . (the current directory) and .. (one level

up) directories. You can choose to filter these out.

If you are making directory browsing available via this mechanism, it is sensible to limit the

directories that can be browsed so that a user cannot browse directory listings in areas not nor-

mally available to him.

An associated and sometimes useful function is rewinddir($dir), which resets the reading of

filenames to the beginning of the directory.

As an alternative to these functions, you can use the dir class provided by PHP. This has the

properties handle and path, and the methods read(), close(), and rewind(), which perform

identically to the non-class alternatives.

Getting Info About the Current Directory

We can obtain some additional information given a path to a file.

The dirname($path) and basename($path) functions return the directory part of the path and

the filename part of the path, respectively. This could be useful for our directory browser, par-

ticularly if we began to build up a complex directory structure of content based on meaningful

directory names and filenames.

We could also add to our directory listing an indication of how much space is left for uploads

by using the diskfreespace($path) function. If you pass this function a path to a directory, it

will return the number of bytes free on the disk (Windows) or the file system (UNIX) that the

directory is on.

Advanced PHP Techniques

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