PHP read sub-directories and loop through files how to?

Question 1

I need to create a loop through all files in subdirectories. Can you please help me struct my code like this:

$main = "MainDirectory";
loop through sub-directories {
    loop through filels in each sub-directory {
        do something with each file
    }
};

Question 2

Use RecursiveDirectoryIterator in conjunction with RecursiveIteratorIterator.

$di = new RecursiveDirectoryIterator('path/to/directory');
foreach (new RecursiveIteratorIterator($di) as $filename => $file) {
    echo $filename . ' - ' . $file->getSize() . ' bytes <br/>';
}

Question 3

Given:

<input type="text" name="foo[]" />
<input type="text" name="foo[]" />
etc...

in your form, you'd loop over them with

foreach($_POST['foo'] as $index => $value) {
    ...
}

The [] in the field name will be stripped off by PHP and used as a hint that it should expect multiple values with the same name, causing it to create a sub-array inside $_GET/$_POST to accomodate those extra values.

You can also suggest which array keys PHP should use, e.g.

<input type="text" name="foo[1]" value="hi there" />
<input type="text" name="foo[abc]" value="TGIF!" />

echo $_POST['foo'][1]; // outputs "hi there"
echo $_POST['foo']['abc'] // outputs "TGIF!"

Multi-dimensional arrays are also supported, using the same notation/access methods.

Question 4

Some time ago I wrote this function to traverse a directory hierarchy. It will return all file paths contained in the given folder (but not folder paths). You should easily be able to modify it to return only files whose name ends in .jpg.

function traverse_hierarchy($path)
{
    $return_array = array();
    $dir = opendir($path);
    while(($file = readdir($dir)) !== false)
    {
        if($file[0] == '.') continue;
        $fullpath = $path . '/' . $file;
        if(is_dir($fullpath))
            $return_array = array_merge($return_array, traverse_hierarchy($fullpath));
        else // your if goes here: if(substr($file, -3) == "jpg") or something like that
            $return_array[] = $fullpath;
    }
    return $return_array;
}

Question 5

use a flag for that. hope to help.(-:

$imageDir = "img/landMarks/carousel/";
$images = glob($imageDir.'*.jpg');
$flag=1;
foreach ($images as $image){
echo '<div class="item' .($flag?' active':''). '">'.PHP_EOL."tt";
echo '<img src="'.$image.'" alt=""></div>'.PHP_EOL."t";
$flag=0;
}

Question 6

RecursiveDirectoryIterator should do the trick. Unfortunately, the documentation is not great, so here is an example:

$root = '/etc';

$iter = new RecursiveIteratorIterator(
    new RecursiveDirectoryIterator($root, RecursiveDirectoryIterator::SKIP_DOTS),
    RecursiveIteratorIterator::SELF_FIRST,
    RecursiveIteratorIterator::CATCH_GET_CHILD // Ignore "Permission denied"
);

$paths = array($root);
foreach ($iter as $path => $dir) {
    if ($dir->isDir()) {
        $paths[] = $path;
    }
}

print_r($paths);

This generates the following output on my computer:

Array
(
    [0] => /etc
    [1] => /etc/rc2.d
    [2] => /etc/luarocks
    ...
    [17] => /etc/php5
    [18] => /etc/php5/apache2
    [19] => /etc/php5/apache2/conf.d
    [20] => /etc/php5/mods-available
    [21] => /etc/php5/conf.d
    [22] => /etc/php5/cli
    [23] => /etc/php5/cli/conf.d
    [24] => /etc/rc4.d
    [25] => /etc/minicom
    [26] => /etc/ufw
    [27] => /etc/ufw/applications.d
    ...
    [391] => /etc/firefox
    [392] => /etc/firefox/pref
    [393] => /etc/cron.d
)

PHP read sub-directories and loop through files how to?

Answers

php,loops,directory