Page 357 - Beginning PHP 5.3

Chapter 11: Working with Files and Directories
chdir() returns true if PHP managed to change to the specified directory, or false if there was an
error (such as the directory not being found).

The current directory is the directory where PHP first looks for files. If you specify a path that isn ’ t an
absolute or relative path, PHP looks for the file inside the current directory. So the following code
chdir( “/home/matt/myfolder” );
$handle = fopen( “myfile.txt” );
opens the same myfile.txt file as:

$handle = fopen( “/home/matt/myfolder/myfile.txt” );

The current directory is also used as the base directory for relative file paths. For example:
chdir( “/home/joe/images” );
$handle = fopen( “../myfile.txt” ); // Looks for myfile.txt in /home/joe

Usually the current directory defaults to the directory containing the running script. You can retrieve the
current directory by calling getcwd() :
chdir( “/home/matt/newfolder” );

echo getcwd(); // Displays “/home/matt/newfolder”
Creating Directories
To create a new directory, call the mkdir() function, passing in the path of the directory you want to create:
mkdir( “/home/matt/newfolder” );

Note that the parent directory has to exist already ( “ /home/matt ” in the example just shown) for the
function to work. mkdir() returns true if the directory was created, or false if there was a problem.
You can also set permissions for the directory at the time you create it by passing the mode as the second
argument. This works much like using chmod() — see the “ Changing Permissions ” section earlier in the

chapter for details. For example, the following code creates a directory with read, write, and execute
permissions granted to all users:

mkdir( “/home/matt/newfolder”, 0777 );
File and directory modes only work on UNIX systems such as Linux and Mac OS; they have no effect
when used on Windows machines.

Deleting Directories
The rmdir() function removes a given directory. The directory must be empty, and you need
appropriate permissions to remove it. For example:

rmdir( “/home/matt/myfolder” );

If PHP can ’ t remove the directory — for example, because it ’ s not empty — rmdir() returns false ;
otherwise it returns true .
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