#!/usr/bin/php
<?php

/* HTTP "Transfer-Encoding: chunked" decoder
 *
 * This simple script will read a HTTP dump (from ethereal or tcpdump or something)
 * from stdin. This dump should have only the raw HTTP data sent by server. The script
 * will read this raw data, skip any HTTP headers (if present) and start reading
 * chunks. For each chunk read, the raw chunk data is echoed to stdout. So, after
 * this script finishes, you will have the original file decoded from HTTP chunks.
 *
 * This script can only read one "file" (or Chunked-Body) from standard in. After
 * the last chunk from "first file" is detected, the script ends.
 *
 * Usage:  chunk-decode.php < rawhttpdata > restoredfile
 */

//Set the following to True to enable debugging info.
define('VERBOSE',False);

//Reference: http://www.faqs.org/rfcs/rfc2616.html

//Copied from a comment at http://br.php.net/install.unix.commandline
if (version_compare(phpversion(),'4.3.0','<')) {
	define('STDIN',fopen("php://stdin","rb"));
	define('STDOUT',fopen("php://stout","wb"));
	define('STDERR',fopen("php://sterr","w"));
	register_shutdown_function( create_function( '' , 'fclose(STDIN); fclose(STOUT); fclose(STERR); return true;' ) );
	fputs(STDERR,"You use a very old PHP version, UPDATE NOW! (to avoid problems later)\n");
}

function warn($s)
{
	fputs(STDERR,$s."\n");
}


//$filename = "";
//$fp = fopen ($filename, "r");
define('STDIN',fopen("php://stdin","rb"));
$fp  = STDIN;
$out = STDOUT;
$totalsize = 0;
$totalchunks = 0;

$line = fgets($fp);
//Checks if the file starts with a chunk, or if we should first skip HTTP headers
if( sscanf($line,"%x",$chunksize)!=1 )
{
	//Skip HTTP headers
	do{
		$line=fgets($fp);
	}while($line!="\r\n" && !feof($fp));
	//Found a blank line (or EOF)
	if(feof($fp))
	{
		warn("EOF found while skipping headers. Maybe invalid input file?");
		exit(1);
	}
	//Since this is a blank line, I need to read the next line, and it will be a chunk
	$line=fgets($fp);
}

//Chunk-reading loop
while(!feof($fp))
{
	if(sscanf($line,"%x",$chunksize)!=1)
	{
		warn("Invalid format when reading chunk ".($totalchunks+1));
		exit(2);
	}
	if($chunksize==0)
	{
		warn("Happy end. $totalsize octets read/written, from $totalchunks chunks.");
	}

	$totalsize += $chunksize;
	$totalchunks++;

	// For some reason, PHP limits the maximum number of bytes read from a file. So, I need to make a loop.
	$remaining = $chunksize;
	while($remaining>0)
	{
		$data=fread($fp, $remaining);
		if(VERBOSE) { warn("chunk #$totalchunks: read ".strlen($data)." octets of $chunksize ($remaining remaining)."); }
//		if(strlen($data)!=$chunksize)
//		{
//			warn("Read error at chunk $totalchunks: read ".strlen($data)." octets, expected $chunksize octets. Continuing anyway...");
//		}
		fwrite($out,$data);
		$remaining-=strlen($data);
	}

	//Removes the CRLF at end of each chunk-data
	$line=fgets($fp);
	if($line!="\r\n")
	{
		warn("Found extra characters after chunk-data $totalchunks (with expected size $chunksize). Only CRLF was expected. Continuing anyway...");
	}

	//Gets next chunk-size
	$line=fgets($fp);
}


//fclose($fp);

?>