File And Directory Manipulation In PHP (part 2) - Purging The Dead (
Page 10 of 13 )
Not only does PHP let you read directory contents, it also allows you to
create and delete directories with the mkdir() and rmdir() functions
respectively. Consider the following example, which creates a directory,
<?php
// create directory
mkdir("/tmp/stuff") or die ("Could not make directory");
?>
and its mirror image, which removes the newly-created directory.
<?php
// erase directory
rmdir("/tmp/stuff") or die ("Could not erase directory");
?>
As with the other filesystem manipulation functions, these functions too will
fail if the user the Web server is running as lacks sufficient privileges to
create and delete directories on the disk. Directories created with mkdir() will
be owned by the process running the Web server.
It's interesting also to note that the rmdir() function operates only if the
directory to be deleted is completely empty. Try running it on a directory
containing existing files, as below,
<?php
// create directory
mkdir("/tmp/stuff") or die ("Could not make directory");
// create sub-directory
mkdir("/tmp/stuff/personal") or die ("Could not make directory");
// remove parent directory
rmdir("/tmp/stuff") or die ("Could not remove directory");
?>
and you'll be rewarded with the following error:
Warning: mkdir(): File exists in /home/web/rmdir.php on line 4 Could
not remove directory
Since it's unlikely that you'll find empty directories just waiting for your
rmdir() in the real world, you'll normally need to empty the directory manually
prior to calling rmdir() on it. The following example demonstrates, by combining
the unlink() function discussed previously with some recursive logic to create a
function designed specifically to erase the contents of a directory (and its
sub-directories) in one fell swoop:
<?php
// recurses into a directory and empties it
// call it like this: purge("/dir/")
// remember the trailing slash!
function purge($dir)
{
$handle = opendir($dir);
while (false !== ($file = readdir($handle)))
{
if ($file != "." && $file != "..")
{
if (is_dir($dir.$file))
{
purge ($dir.$file."/");
rmdir($dir.$file);
}
else
{
unlink($dir.$file);
}
}
}
closedir($handle);
}
?>
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