File handling is an important part of any web application. You often need to open and process a file for different tasks.
PHP has several functions for creating, reading, uploading, and editing files.
|Be careful when manipulating files!
When you are manipulating files you must be very careful. You can do a lot of damage if you do something wrong. Common errors are: editing the wrong file, filling a hard-drive with garbage data, and deleting the content of a file by accident.
The readfile() function reads a file and writes it to the output buffer.
Assume we have a text file called "webdictionary.txt", stored on the server, that looks like this:
The PHP code to read the file and write it to the output buffer is as follows (the readfile() function returns the number of bytes read on success):
The readfile() function is useful if all you want to do is open up a file and read its contents.
The next chapters will teach you more about file handling.