#Php include file code#

Likewise, the require statement may also be used to include the file, as shown in Listing 1.25: Listing 1.25. When a file is requested to be included by a PHP script, PHP first checks the current directory for the file followed by the include file path before returning an error. Often, all the includable files are stored in a directory that is then designated part of the PHP include file search path. In most practical situations, files that are included into PHP scripts are not in the same directory as the script that actually requires them. Note that non-PHP files (such as HTML files) may also be included they will be dumped into the output as you would expect.Īssuming that library.inc is in the same directory as the actual script, you could use your is_leapyear() function that exists within the library.inc file, as shown in Listing 1.24: Listing 1.24.

#Php include file code#

This means that all PHP code must be in appropriate tags, and so on. Note that although this file is designed to be 'included' rather than directly executed by PHP, it still conforms to all the rules of a normal PHP script. Following that logic, I'll assume that a PHP file exists called library.inc, which contains the is_leapyear() function defined in Listing 1.19. If URL wrappers are enabled in PHP (see Chapter 20, 'Working with the File System,' and Chapter 21, 'Network I/O'), the filename provided to the include statement can be a HTTP address of the file to be loaded.Īs I mentioned earlier, it is good practice to separate functions and code that are used in multiple scripts into a separate file. Note that for every file inclusion function previously listed, the file to load can be a string constant or a variable containing the name of the file. The general syntax of both the include and require statements are as follows: Because it is unacceptable to define the same function multiple times within a script, these functions allow the developer to include a script as needed without having to check whether it has been previously loaded. If an attempt is made to load a file twice using one of these two methods, it will be ignored. When the include_once/ require_once statements are used, the file cannot be loaded or executed multiple times. The only difference between the include/ require and include_once/ require_once statements is how many times a given file will actually be loaded. First, let's discuss how each of the two flavors work. As you may suspect, of these four statements only the include and require statements actually differ with any great significance, and it is those differences that I'll focus on. Regardless of the reasons, inclusion of external files is accomplished through the include, include_once, require, and require_once PHP statements. Furthermore, by storing sensitive static information such as database login information in separate files, they can be safely placed outside the Web tree of the server and thus be inaccessible by the public. In PHP, this organization is accomplished by separating your scripts into multiple files and including them when appropriate.

In this respect, and as you accumulate an ever-growing library of functions, the need to organize them becomes more and more paramount. It is always good practice to make your scripts as modular as possible, designing your functions in such a way that they can be used in other PHP scripts.