Re: [PHP] getting download resume to work

Can you help explain this code? It looks like you're on the right track but
have a few flaws (at first glance).

> <?php
> session_cache_limiter('public');
> session_start();

Is there a reason to be using sessions here?

> set_time_limit(0);
> $file=$_REQUEST['file'];
> $extstart=strpos($file, ".");

What does $extstart contain now?

> $ext=substr($file, $extstart+1);

So $ext is now a piece of the file. Why?

> $dir="d:\\downloadable_courses";
> $size=filesize($dir."\\".$file);
> header("Accept-Ranges: bytes");

So $size is now the size of the entire file (not the piece).

> if(isset($_ENV['HTTP_RANGE'])) {
> list($a, $range)=explode("=",$_ENV['HTTP_RANGE']);

So $a is now bytes, and $range is something like 123-456

> str_replace($range, "-", $range);

This makes no sense. The range requested is bytes 123 through 456, and you're
converting this to 123456. Why?

> $size2=$size-1;
> header("Content-Range: $range$size2/$size");
> $new_length=$size2-$range;

This will definitely not work, based on my comments above.

If someone sends this header:

Range: bytes=0-1023

and your resource is 2048 bytes in size, your response should include this
header:

Content-Range: bytes 0-1023/2048

Work on generating the correct string before you bother actually using them as
headers and trying for the full solution.

Hope that helps.

Chris

=====
Become a better Web developer with the HTTP Developer's Handbook
http://httphandbook.org/

All answers are below your questions...
Thank you for taking the time to parse through my code and try to understand
what I am doing, I really appreciate it, this is the first time I have tried
something like this and have been hung up on it for a couple days now...
Scott

-----Original Message-----
From: Chris Shiflett [mailto:shiflett@php.net]
Sent: Thursday, September 11, 2003 8:21 PM
To: Raditha Dissanayake; Scott Dotson; php-general@lists.php.net
Subject: Re: [php] getting download resume to work


Can you help explain this code? It looks like you're on the right track but
have a few flaws (at first glance).

> <?php
> session_cache_limiter('public');
> session_start();

Is there a reason to be using sessions here?
>>>>>>>ANS: not really as of yet, but, there will be as I will be
restricting downloads to authenticated users...

> set_time_limit(0);
> $file=$_REQUEST['file'];
> $extstart=strpos($file, ".");

What does $extstart contain now?
>>>>>>>ANS: just the first part of the name, before the extension, (for no
reason)

> $ext=substr($file, $extstart+1);

So $ext is now a piece of the file. Why?
>>>>>>>ANS: this is done so that I can set the
==header("Content-Type: application/".$ext);==

> $dir="d:\\downloadable_courses";
> $size=filesize($dir."\\".$file);
> header("Accept-Ranges: bytes");

So $size is now the size of the entire file (not the piece).
>>>>>>>ANS: correct

> if(isset($_ENV['HTTP_RANGE'])) {
> list($a, $range)=explode("=",$_ENV['HTTP_RANGE']);

So $a is now bytes, and $range is something like 123-456
>>>>>>>ANS: partly correct, what I receive is
=="Range: bytes=14232-"==
it has no last number.

> str_replace($range, "-", $range);

This makes no sense. The range requested is bytes 123 through 456, and
you're
converting this to 123456. Why?
>>>>>>>ANS: when I left it on what it would send to the browser would be
=="header("Content-Range: 123--456/457");"==
(it would tack on an extra dash symbol (-) and the browser did not
understand it)

> $size2=$size-1;
> header("Content-Range: $range$size2/$size");
> $new_length=$size2-$range;

This will definitely not work, based on my comments above.
>>>>>>>ANS: it appears to work enough that FlashGet will try to
recover/resume and it completes, but, the byte count is always off by around
1 or so bytes and I cannot figure out why...

If someone sends this header:

Range: bytes=0-1023

and your resource is 2048 bytes in size, your response should include this
header:

Content-Range: bytes 0-1023/2048

Work on generating the correct string before you bother actually using them
as
headers and trying for the full solution.
>>>>>>>ANS: I have set it to log to a text file previously and it is always
1 byte different. I am at a total loss as to where it is happening, I will
attach the the log files that I have been pouring over as well the actual
script to you...

Hope that helps.

Chris

=====
Become a better Web developer with the HTTP Developer's Handbook
http://httphandbook.org/

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got it to work using fseek,
feel like a bozo posting this when it was my lack of thinking in the first
place as to why it didn't work.
thanks all for the help...
Scott

"Chris Shiflett" <shiflett@php.net> wrote in message
news:20030912032127.42923.qmail@web14301.mail.yaho o.com...
> Can you help explain this code? It looks like you're on the right track
but
> have a few flaws (at first glance).
>
> > <?php
> > session_cache_limiter('public');
> > session_start();
>
> Is there a reason to be using sessions here?
>
> > set_time_limit(0);
> > $file=$_REQUEST['file'];
> > $extstart=strpos($file, ".");
>
> What does $extstart contain now?
>
> > $ext=substr($file, $extstart+1);
>
> So $ext is now a piece of the file. Why?
>
> > $dir="d:\\downloadable_courses";
> > $size=filesize($dir."\\".$file);
> > header("Accept-Ranges: bytes");
>
> So $size is now the size of the entire file (not the piece).
>
> > if(isset($_ENV['HTTP_RANGE'])) {
> > list($a, $range)=explode("=",$_ENV['HTTP_RANGE']);
>
> So $a is now bytes, and $range is something like 123-456
>
> > str_replace($range, "-", $range);
>
> This makes no sense. The range requested is bytes 123 through 456, and
you're
> converting this to 123456. Why?
>
> > $size2=$size-1;
> > header("Content-Range: $range$size2/$size");
> > $new_length=$size2-$range;
>
> This will definitely not work, based on my comments above.
>
> If someone sends this header:
>
> Range: bytes=0-1023
>
> and your resource is 2048 bytes in size, your response should include this
> header:
>
> Content-Range: bytes 0-1023/2048
>
> Work on generating the correct string before you bother actually using
them as
> headers and trying for the full solution.
>
> Hope that helps.
>
> Chris
>
> =====
> Become a better Web developer with the HTTP Developer's Handbook
> http://httphandbook.org/