19.8.1 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.
19.8.2 Solution
$d = opendir('/tmp') or die($php_errormsg);
while (false !== ($f = readdir($d))) {
print "$f\n";
}
closedir($d);
19.8.3 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 the
readdir( ), rewinddir( ), and closedir( ) functions.
There's also a $path property that contains the full path of the opened
directory.
Here's how to iterate through files with the object-oriented
interface:
print '<select name="files">';
$d = dir('/usr/local/upload') or die($php_errormsg);
while (false !== ($f = $d->read())) {
if (is_file($d->path.'/'.$f)) {
print '<option> ' . $f . '</option>';
}
}
$d->close();
In this example, $d->path is /usr/local/upload.