Creation of zip folder in php - ftp

Question

I am trying to create a zip folder of my downloaded images.
Here is my code. I am not getting any errors, but the zip is not getting downloaded.The code is getting compiled and I am getting the output till the display part of the current directory, but after that the code seems to go wrong somewhere and I am not able to get any Zip archive.
<?php
$conn_id=ftp_connect("localhost") or die("Could not connect");
ftp_login($conn_id,"kishan","ubuntu"); //login to ftp localhost
echo "The current directory is " . ftp_pwd($conn_id); //display current directory
ftp_chdir($conn_id,'/var/www/test1'); //changing to the directory where my images are downloaded.
echo "<br/><p> Changing to directory" . ftp_pwd($conn_id);
$file_folder=".";
echo "<br/> The content of the directory is <br/>";
print_r(ftp_rawlist($conn_id,".")); // display the contents of the directory
if(extension_loaded('zip')) //check whether extension is loaded
{
$zip=new ZipArchive();
$zip_name="a.zip"; //some name to my zip file
if($zip->open($zip_name,ZIPARCHIVE::CREATE)!==TRUE)
{
$error="Sorry ZIP creation failed at this time";
}
$contents=ftp_nlist($conn_id,".");
foreach($contents as $file) //addition of files to zip one-by-one
{
$zip->addFile($file_folder.$file);
}
$zip->close(); //seal the zip
}
if(file_exists($zip_name)) //Content-dispostion of my zip file
{
header('Content-type:application/zip');
header('Content-Disposition:attachment; filename="'.$zip_name.'"');
readfile($zip_name);
unlink($zip_name);
}
?>

Answer 1

I just found that there is something wrong with the data that is passed to the for loop.
$contents=ftp_nlist($conn_id,".");
foreach($contents as $file) //addition of files to zip one-by-one
{
$zip->addFile($file_folder.$file);
}
I am not sure exactly where the thing is going wrong but here is the update. What I did was write markup using html and then passing the files to this php script via a POST method, as
foreach($post['files'] as $file){
$zip->addFile($file_folder.$file);} // Adding files into zip
This code is absolutely working fine, but now I need to figure out why post method is working and compressing my files whereas my normal for looping over files is not!!