PHP Directory Listing Script

[kbjradmin]

i have this script that lists the files in a current directory as well as a directory structure of all the directories under a certain level. the first level of directories works fine, but below that it has problems. the page this is on is at http://cs.clark.edu/~jbrum4030/ctec122/directory.php (try clicking on "labs" to see what i'm talking about) and the php code is below. please help.

<?php


// lists all the files is a given directory
function listing()
{
    $relPath = $_REQUEST['path'] ;
    $path = "/home/students/jbrum4030/public_html/ctec122".$relPath;
        
    //using the opendir function
    $dir_handle = @opendir($path) or die("Cannot Open Directory $path");
    
    echo "<p>Directory Listing For:<br />~/public_html/ctec122${relPath}<br /><br />File<span>Size (bytes)</span></p>";
    
    //running the while loop
    while ( $file = readdir($dir_handle) ) 
    {
        if ( $file != '.' && $file != '..' && $file[0] == '.' )
        {
            continue;
        }
        elseif ( $file == '.' )
        {
            echo "<p><a href='?path=${relPath}'>$file</a><span>".filesize($file)."</span></p>\n";
            continue;
        }
        elseif ( $file == '..' )
        {
            $relPath = upLevel($relPath);
            echo "<p><a href='?path=${relPath}'>$file</a><span>".filesize($file)."</span></p>\n";
            continue;
        }
        if ( ! is_dir($file) )
        {
            echo "<p><a href='$file'>$file</a><span>".filesize($file)."</span></p>\n";
        }
        else
        {
            echo "<p><a href='?path=${relPath}/${file}'>$file</a><span>".filesize($file)."</span></p>\n";
        }
    }
    
    echo "<br />";
    
    //closing the directory
    closedir($dir_handle);
}


// moves the current directory up one level (used by listing function)
function upLevel( $path )
{
    $excess = strrchr($path,"/");
    $excessLen = strlen($excess);
    $pathLen = strlen($path);
    $newPath = substr($path,0,($pathLen - $excessLen));
    return $newPath;
}


// checks all directories in the current directory for sub-directories (used by directory listing and itself)
function recurse( $path, $relPath, $level )
{
    // open the directory
    $dir_handle = @opendir($path.$relPath) or die("Could not open $path");
    
    // go through each file checking if they are directories
    while ( $file = readdir($dir_handle) )
    {
        if ( is_dir($file) && $file != '.' && $file != '..' )
        {
            $dirs[] = $file;
        }
    }
    
    // check that directory is not empty
    if ( count($dirs) == 0 )
    {
        return;
    }
    
    echo "<div class=\"level${level}\">\n";
    
    // go through each directory, repeating the search process for each
    foreach ( $dirs as $index => $file )
    {
        $tempRelPath = $relPath.'/'.$file;
        echo "<a href=\"?path=${tempRelPath}\">${file}</a><br />\n";
        recurse($path, $tempRelPath, ($level + 1));
    }
    
    echo "</div>\n";
    
    // closing the directory
    closedir($dir_handle);
}


// lists all directories recursively in the current directory
function directoryListing()
{
    echo "<p>Directory Structure</p>\n";

    // default the array dirs
    $dirs = array();
    
    // level var used to know how many recursion levels has been traversed
    $level = 1;
    
    // the root path to be listed from
    $path = '/home/students/jbrum4030/public_html/ctec122';
    
    echo "<a href=\"?path=\">ctec122</a>\n";
    
    recurse($path, '', $level);
    
    echo "<br />\n";
}
?>

[garrettroyce]

the problem is the usage of is_dir()

readdir returns the name of a file [b]without the path[b] and is_dir uses the current working directory, not [b]the same path as readdir[b].

So, when you want to check the file /home/user/public_html/test/dir/ you are really checking /home/user/public_html/dir

Also, when you use paths, use the path relative of the site's home directory, ie /home/username/public_html should be /

Also also, use !== and === not != and == for this. If you have a directory named 0, $file == false evaluates to true and $file === false evaluates to false!

[misson]

Note that the error message says (e.g.) "stat failed for lab1" when getting the size of ctec122/labs/lab1. The current directory is ctec122, so filesize("lab1") is looking for lab1 in ctec122. Try filesize($path . '/' . $file).

You've also got a sizable security hole in listing() by not sanitizing $_REQUEST['path'] (try http://cs.clark.edu/~jbrum4030/ctec1...hp?path=/%2e./). Use realpath to get the canonical path and test that $path begins with the (safe) base path.

No need for upLevel when you've got dirname

The doc is nicely structured (not too many elements) except for the <br>s in the file listing. An unordered list is more appropriate. Furthermore, you can replace the nested <div>s in the directory listing with <ul>s, allowing you to drop the .level[1-4] classes and easily add icons (if you want) using list-style-image. Once you do that, refactor directoryListing() and recurse() so the link for each directory is printed from only 1 spot.

Edit: You know what? The file information is tabular data. A table might be the best way of structuring the file information, semantically speaking.

[kbjradmin]

thanks both of you.

[garrettroyce]

No problem. Does it work for you now?

[kbjradmin]

yes, it works now.

[misson]

Looking good. The forum poster was "fixing" my example of a dangerous URL, so I had to unfix it. Here it is again:
http://cs.clark.edu/~jbrum4030/ctec1...hp?path=/%2e./

There are more dangerous URIs, so you'd better fix that security hole quickly.