19.7. Processing All Files in a Directory Recursively

Problem

You want to iterate over all files in a directory. For example, you want to create a select box in a form that lists all the files in a directory.

Solution

Get a directory handle with opendir( ) and then retrieve each filename with readdir( ):

$d = opendir('/tmp') or die($php_errormsg);
while (false !== ($f = readdir($d))) {
    print "$f\n";
}
closedir($d);

Discussion

The code in the solution tests the return value of readdir( ) with the nonidentity operator (!==) so that the code works properly with filenames that evaluate to false, such as a file named 0.

The function readdir( ) returns each entry in a directory, whether it is a file, directory, or something else (such as a link or a socket). This includes the metaentries “.” (current directory) and “..” (parent directory). To just return files, use the is_file( ) function as well:

print '<select name="files">';
$d = opendir('/usr/local/upload') or die($php_errormsg);
while (false !== ($f = readdir($d))) {
    if (is_file("/usr/local/upload/$f")) {
        print '<option> ' . $f . '</option>';
    }
}
closedir($d);
print '</select>';

Because readdir( ) returns only the filename of each directory entry, not a full pathname, you have to prepend the directory name to $f before you pass it to is_file( ).

PHP also has an object-oriented interface to directory information. The dir( ) function returns an object on which you can call read( ), rewind( ), and close( ) methods, which act like ...

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