<?
/*
########################################################################                                        
Copyright 2007, Michael Schrenk                                                                                 
   This software is designed for use with the book,                                                             
   "Webbots, Spiders, and Screen Scarpers", Michael Schrenk, 2007 No Starch Press, San Francisco CA             
                                                                                                                
W3CŽ SOFTWARE NOTICE AND LICENSE                                                                                
                                                                                                                
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      or derivative work.                                                                                       
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########################################################################                                        
*/

#-----------------------------------------------------------------------
# LIB_http                                                              
#                                                                       
# F U N C T I O N S                                                     
#                                                                       
# http_get()                                                            
#    Fetches a file from the Internet with the HTTP protocol            
# http_header()                                                         
#    Same as http_get(), but only returns HTTP header instead of        
#    the normal file contents                                           
# http_get_form()                                                       
#    Submits a form with the GET method                                 
# http_get_form_withheader()                                            
#    Same as http_get_form(), but only returns HTTP header instead of   
#    the normal file contents                                           
# http_post_form()                                                      
#    Submits a form with the POST method                                
# http_post_withheader()                                                
#    Same as http_post_form(), but only returns HTTP header instead of  
#    the normal file contents                                           
# http_header()                                                         
#                                                                       
# http()                                                                
#   A common routine called by all of the previously described          
#   functions. You should always use one of the other wrappers for this 
#   routine and not call it directly.                                   
#                                                                       
#-----------------------------------------------------------------------
# R E T U R N E D   D A T A                                             
# All of these routines return a three dimensional array defined as     
# follows:	    												        
#    $return_array['FILE']   = Contents of fetched file, will also      
#                              include the HTTP header if requested    
#    $return_array['STATUS'] = CURL generated status of transfer        
#    $return_array['ERROR']  = CURL generated error status              
########################################################################

/***********************************************************************
Webbot defaults (scope = global)                                       
----------------------------------------------------------------------*/
# Define how your webbot will appear in server logs
define("WEBBOT_NAME", "Test Webbot");

# Length of time cURL will wait for a response (seconds)
define("CURL_TIMEOUT", 25);

# Location of your cookie file. (Must be fully resolved local address)
define("COOKIE_FILE", "c:\cookie.txt");

# DEFINE METHOD CONSTANTS
define("HEAD", "HEAD");
define("GET",  "GET");
define("POST", "POST");

# DEFINE HEADER INCLUSION
define("EXCL_HEAD", FALSE);
define("INCL_HEAD", TRUE);

/***********************************************************************
User interfaces         	                                            
-------------------------------------------------------------			
*/

/***********************************************************************
function http_get($target, $ref)                                        
-------------------------------------------------------------           
DESCRIPTION:                                                            
        Downloads an ASCII file without the http header                 
INPUT:                                                                  
        $target       The target file (to download)                     
        $ref          The server referer variable                       
OUTPUT:                                                                 
        $return_array['FILE']   = Contents of fetched file, will also   
                                 include the HTTP header if requested   
        $return_array['STATUS'] = CURL generated status of transfer     
        $return_array['ERROR']  = CURL generated error status           
***********************************************************************/
function http_get($target, $ref)
    {
    return http($target, $ref, $method="GET", $data_array="", EXCL_HEAD);
    }

/***********************************************************************
http_get_withheader($target, $ref)                                      
-------------------------------------------------------------           
DESCRIPTION:                                                            
        Downloads an ASCII file with the http header                    
INPUT:                                                                  
        $target       The target file (to download)                     
        $ref          The server referer variable                       
OUTPUT:                                                                 
        $return_array['FILE']   = Contents of fetched file, will also   
                                 include the HTTP header if requested   
        $return_array['STATUS'] = CURL generated status of transfer     
        $return_array['ERROR']  = CURL generated error status           
***********************************************************************/
function http_get_withheader($target, $ref)
    {
    return http($target, $ref, $method="GET", $data_array="", INCL_HEAD);
    }

/***********************************************************************
http_get_form($target, $ref, $data_array)                               
-------------------------------------------------------------           
DESCRIPTION:                                                            
        Submits a form with the GET method and downloads the page       
        (without a http header) referenced by the form's ACTION variable
INPUT:                                                                  
        $target       The target file (to download)                     
        $ref          The server referer variable                       
        $data_array   An array that defines the form variables          
                      (See "Webbots, Spiders, and Screen Scrapers" for  
                      more information about $data_array)               
OUTPUT:                                                                 
        $return_array['FILE']   = Contents of fetched file, will also   
                                 include the HTTP header if requested   
        $return_array['STATUS'] = CURL generated status of transfer     
        $return_array['ERROR']  = CURL generated error status           
***********************************************************************/
function http_get_form($target, $ref, $data_array)
    {
    return http($target, $ref, $method="GET", $data_array, EXCL_HEAD);
    }

/***********************************************************************
http_get_form_withheader($target, $ref, $data_array)                    
-------------------------------------------------------------           
DESCRIPTION:                                                            
        Submits a form with the GET method and downloads the page       
        (with http header) referenced by the form's ACTION variable     
INPUT:                                                                  
        $target       The target file (to download)                     
        $ref          The server referer variable                       
        $data_array   An array that defines the form variables          
                      (See "Webbots, Spiders, and Screen Scrapers" for  
                      more information about $data_array)               
OUTPUT:                                                                 
        $return_array['FILE']   = Contents of fetched file, will also   
                                 include the HTTP header if requested   
        $return_array['STATUS'] = CURL generated status of transfer     
        $return_array['ERROR']  = CURL generated error status           
***********************************************************************/
function http_get_form_withheader($target, $ref, $data_array)
    {
    return http($target, $ref, $method="GET", $data_array, INCL_HEAD);
    }

/***********************************************************************
http_post_form($target, $ref, $data_array)                              
-------------------------------------------------------------           
DESCRIPTION:                                                            
        Submits a form with the POST method and downloads the page      
        (without http header) referenced by the form's ACTION variable  
INPUT:                                                                  
        $target       The target file (to download)                     
        $ref          The server referer variable                       
        $data_array   An array that defines the form variables          
                      (See "Webbots, Spiders, and Screen Scrapers" for  
                      more information about $data_array)               
OUTPUT:                                                                 
        $return_array['FILE']   = Contents of fetched file, will also   
                                 include the HTTP header if requested   
        $return_array['STATUS'] = CURL generated status of transfer     
        $return_array['ERROR']  = CURL generated error status           
***********************************************************************/
function http_post_form($target, $ref, $data_array)
    {
    return http($target, $ref, $method="POST", $data_array, EXCL_HEAD);
    }

function http_post_withheader($target, $ref, $data_array)
    {
    return http($target, $ref, $method="POST", $data_array, INCL_HEAD);
    }

function http_header($target, $ref)
    {
    return http($target, $ref, $method="HEAD", $data_array="", INCL_HEAD);
    }

/***********************************************************************
http($url, $ref, $method, $data_array, $incl_head)                      
-------------------------------------------------------------			
DESCRIPTION:															
	This function returns a web page (HTML only) for a web page through	
	the execution of a simple HTTP GET request.							
	All HTTP redirects are automatically followed.						
                                                                        
    IT IS BEST TO USE ONE THE EARLIER DEFINED USER INTERFACES           
    FOR THIS FUNCTION                                                   
                                                                        
INPUTS:																	
	$target      Address of the target web site		 					
	$ref		 Address of the target web site's referrer				
	$method		 Defines request HTTP method; HEAD, GET or POST         
	$data_array	 A keyed array, containing query string                 
	$incl_head	 TRUE  = include http header                            
                 FALSE = don't include http header                      
                                                                        
RETURNS:																
    $return_array['FILE']   = Contents of fetched file, will also       
                              include the HTTP header if requested      
    $return_array['STATUS'] = CURL generated status of transfer         
    $return_array['ERROR']  = CURL generated error status               
***********************************************************************/
function http($target, $ref, $method, $data_array, $incl_head)
	{
    # Initialize PHP/CURL handle
	$ch = curl_init();

    # Prcess data, if presented
    if(is_array($data_array))
        {
	    # Convert data array into a query string (ie animal=dog&sport=baseball)
        foreach ($data_array as $key => $value) 
            {
            if(strlen(trim($value))>0)
                $temp_string[] = $key . "=" . urlencode($value);
            else
                $temp_string[] = $key;
            }
        $query_string = join('&', $temp_string);
        }
        
    # HEAD method configuration
    if($method == HEAD)
        {
    	curl_setopt($ch, CURLOPT_HEADER, TRUE);                // No http head
	    curl_setopt($ch, CURLOPT_NOBODY, TRUE);                // Return body
        }
    else
        {
        # GET method configuration
        if($method == GET)
            {
            if(isset($query_string))
                $target = $target . "?" . $query_string;
            curl_setopt ($ch, CURLOPT_HTTPGET, TRUE); 
            curl_setopt ($ch, CURLOPT_POST, FALSE); 
            }
        # POST method configuration
        if($method == POST)
            {
            if(isset($query_string))
                curl_setopt ($ch, CURLOPT_POSTFIELDS, $query_string);
            curl_setopt ($ch, CURLOPT_POST, TRUE); 
            curl_setopt ($ch, CURLOPT_HTTPGET, FALSE); 
            }
    	curl_setopt($ch, CURLOPT_HEADER, $incl_head);   // Include head as needed
	    curl_setopt($ch, CURLOPT_NOBODY, FALSE);        // Return body
        }
        
	curl_setopt($ch, CURLOPT_COOKIEJAR, COOKIE_FILE);   // Cookie management.
	curl_setopt($ch, CURLOPT_COOKIEFILE, COOKIE_FILE);
	curl_setopt($ch, CURLOPT_TIMEOUT, CURL_TIMEOUT);    // Timeout
	curl_setopt($ch, CURLOPT_USERAGENT, WEBBOT_NAME);   // Webbot name
	curl_setopt($ch, CURLOPT_URL, $target);             // Target site
	curl_setopt($ch, CURLOPT_REFERER, $ref);            // Referer value
	curl_setopt($ch, CURLOPT_VERBOSE, FALSE);           // Minimize logs
	curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);    // No certificate
	curl_setopt($ch, CURLOPT_FOLLOWLOCATION, TRUE);     // Follow redirects
	curl_setopt($ch, CURLOPT_MAXREDIRS, 4);             // Limit redirections to four
	curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);     // Return in string
    
    # Create return array
    $return_array['FILE']   = curl_exec($ch); 
    $return_array['STATUS'] = curl_getinfo($ch);
    $return_array['ERROR']  = curl_error($ch);
    
    # Close PHP/CURL handle
  	curl_close($ch);
    
    # Return results
  	return $return_array;
    }
?>