Download problem

pzbrawl

This code, run from a shared linux/apache web server, fails at the end of a 7MB .zip download with a "source file could not be read" error at the client.

    $path = "xxx/";
    $file = "yyy.zip";
    $filetype = "application/x-zip-compressed";
    $fsize = filesize( $path . $file );
    header( "Content-Disposition: attachment; filename=\"$file\"");
    header( "Content-type: \"$filetype\"" );
    header("Content-Length: $fsize" ); 
    header( 'Pragma: no-cache' );
    header( 'Expires: 0' );
    return @readfile( $path . $file );

When the content-length header is commented out, some users can download successfully, while others get incomplete zips.

Setting type to "application/octet-stream" or "encoding/x-compress" yields the same result.

Setting type to "application/gzip" gets rid of the error report when length is set, but yields a clientsize "unexpected end of file" error.

The .zip file is valid.

Any ideas of what might be going on?

bradgrafelman

How long do the downloads last? Have you made sure to disable the max execution time?

pzbrawl

The download takes about a minute on our test machines. It's doubtful any user is using dialup.

Additional info:

The file on the server is correct.

Downloaded from the server to our test machines without the length header in the code shown above, the result file has the HTML of the PHP-generated download page appended to it. On some users' boxes, however, downloading without the length header truncates the download result to about 1.2MB.

Downloaded to our test machines with the length header, the file is 30290 bytes shorter than the original, and generates an "unexpected end of archive" error from winrar.

If we use an ftp script instead ...

function dlftp() {
  $path = "xxx/";
  $file = "yyy.rar" ;
  $conn = ftp_connect( "ftpaddress") or die( "Could not connect to ftp server"); 
  @ftp_login( $conn, "user", "pswd" ) or die( "Could not log into ftp server" );
  return @readfile( ftp_get( $conn, $file, $path . $file, FTP_BINARY ));
}

... no error is raised but the download file is 10,002 bytes short.

What could be going on?

bradgrafelman

Well...

bradgrafelman wrote:
Have you made sure to disable the max execution time?

pzbrawl

The same problem occurs with a file that is less than one-tenth the size.

pzbrawl

The same errors occur with files that are a tenth the size and download in less than ten secs, and disabling execution time limit has zero effect.