Implementing Internet Protocols with PHP Page 2

Listfiles Function Explained

Next, we define a commonly used function. The function is contained in a file called functions.php. It defines a function called listfiles(). This function takes two arguments, the connection resource and the directory:

<?php
//list files
function listfiles($con,$directory){
echo '<table>';
echo '<tr>
    <td></td>
    <td>'.ftp_pwd($con).'</td>
  </tr>
  <tr>
    <td><b>File Name</b></td>
    <td><b>Action</b></td>
  </tr>';
   $a = ftp_nlist($con, $directory);
                foreach($a as $value){
                 if(strpos($value,'.') > 0){
                         $img='images/subpage.gif';
                         $open="";
                         }else{
                                 $img='images/fb.gif';
                                 $open='<a href="'.$_SERVER['PHP_SELF'].'?action=view&dirs='.$value.'">
                                 <img src="images/open.png" border="0">Open</a>';
                             }
 echo '<tr class="block">';
    if($open==""){
 echo '<td><img src="'.$img.'" border="0">'.trim($value).'
    </td>
    <td><a href="'.$_SERVER['PHP_SELF'].'?action=upload&file='.$value.'"><img src="images/upload.bmp" border="0">
    </a>|<a href="'.$_SERVER['PHP_SELF'].'?action=download&file='.$value.'">
    <img src="images/download.png" border="0"></a>|<a href="'.$_SERVER['PHP_SELF'].'?action=delete&file='.$value.'">
    <img src="images/trash.png" border="0"></a>
    </td>';
    }else{
  echo '<td><img src="'.$img.'" border="0">'.trim($value).'</td><td>
    '.$open.'';
echo '</td>';
             }
 echo  '</tr>';
    }
  // close the connection
//ftp_close($con);
echo '</table>';
}
?>

The function starts by building a dynamic table with the headers File and Action:

echo '<table>';
echo '<tr>
    <td></td>
    <td>'.ftp_pwd($con).'</td>
  </tr>
  <tr>
    <td><b>File Name</b></td>
    <td><b>Action</b></td>
  </tr>';

Then it calls the ftp_nlist() function to list the files in the given directory and stores the result in a variable called $a:

   $a = ftp_nlist($con, $directory);

Now remember that the file names are returned in an array, so we must break the array down to list the individual files. The foreach loop does exactly that:

foreach($a as $value){

Sometimes a directory name is returned instead of a file name, so we need to be able to separate the two. The code below makes that separation by checking if the returned name contains a dot (.). This is because all file names contain a dot that separate the actual file name from the extension:

if(strpos($value,'.') > 0){
                         $img='images/subpage.gif';
                         $open="";

If there is no dot then the code proceeds to display the appropriate image and directory name. In addition it also creates a link that enables users to access or open up the directory to view its contents:

                         }else{
                                 $img='images/fb.gif';
                                 $open='<a href="'.$_SERVER['PHP_SELF'].'?action=view&dirs='.$value.'">
                                 <img src="images/open.png" border="0">Open</a>';
                             }

The remaining code simply sets up three other links that enable the user to upload, download and delete a file from the list or directory. If the listed name is that of a directory than only one link is displayed:

echo '<tr class="block">';
    if($open==""){
 echo '<td><img src="'.$img.'" border="0">'.trim($value).'
    </td>
    <td><a href="'.$_SERVER['PHP_SELF'].'?action=upload&file='.$value.'"><img src="images/upload.bmp" border="0">
    </a>|<a href="'.$_SERVER['PHP_SELF'].'?action=download&file='.$value.'">
    <img src="images/download.png" border="0"></a>|<a href="'.$_SERVER['PHP_SELF'].'?action=delete&file='.$value.'">
    <img src="images/trash.png" border="0"></a>
    </td>';
    }else{
  echo '<td><img src="'.$img.'" border="0">'.trim($value).'</td><td>
    '.$open.'';
echo '</td>';
             }
 echo  '</tr>';
    }

The table is then closed and the connection to the FTP server is also closed. Figure 1 shows an image of what this function accomplishes:

Click here for larger image

Figure 1. FTP::Control Panel Showing listfiles in Action

Remember to activate the FTP server before running this FTP client. The password and usernames that I’ve used here are located in a file called ftpconnect.php. If you are going to store the connection details in this way, make sure that this file is stored outside of your root directory.