chamilo-lms/main/exercice/hotpotatoes.lib.php

<?php //$id: $
/* For licensing terms, see /license.txt */
/**
*	Code library for HotPotatoes integration.
*	@package chamilo.exercise
* 	@author Istvan Mandak (original author)
*/
$dbTable = Database::get_course_table(TABLE_DOCUMENT);
/**
 * Creates a hotpotato directory
 *
 * If a directory of that name already exists, don't create any. If a file of that name exists, remove it and create a directory
 * @param	string	Wanted path
 * @return boolean	Always true so far
 */
function hotpotatoes_init($baseWorkDir) {
	//global $_course, $_user;
	$documentPath=$baseWorkDir.'/';
	if (!is_dir($documentPath)) {
		if (is_file($documentPath)) {
			@unlink($documentPath);
		}
		@mkdir($documentPath, api_get_permissions_for_new_directories());
		return true;
	} else {
		//if this directory already exists, return false
		return false;
	}
	//why create a .htaccess here?
	//if (!is_file($documentPath.".htacces"))
	//{
	//		if (!($fp = fopen($documentPath.".htaccess", "w"))) {
	//	}
	//	$str = "order deny,allow\nallow from all";
	//	if (!fwrite($fp,$str)) { }
	//}
}

/**
 * Gets the title of the quizz file given as parameter
 * @param	string	File name
 * @param	string	File path
 * @return	string	The exercise title
 */
function GetQuizName($fname,$fpath) {

	$title = "";
	$title = GetComment($fname);

	if ($title=="") {
		if (file_exists($fpath.$fname)) {
			if (!($fp = fopen($fpath.$fname, "r"))) {
			//die("could not open Quiz input");
				return basename($fname);
			}

			$contents = fread($fp, filesize($fpath.$fname));
			fclose($fp);

			$contents = api_strtolower($contents);

			$pattern = array ( 1 => "title>", 2 => "/title>");

			$s_contents = api_substr($contents,0,api_strpos($contents,$pattern["2"])-1);
			$e_contents = api_substr($s_contents,api_strpos($contents,$pattern["1"])+api_strlen($pattern["1"]),api_strlen($s_contents));

			$title = $e_contents;
		} else {
			return '';
		}
	}
	return $title;
}

/**
 * Gets the comment about a file from the corresponding database record
 * @param	string	File path
 * @return	string	Comment from the database record
 * Added conditional to the table if is empty.
 */
function GetComment($path,$course_code='') {
	global $dbTable;

	if (!empty($course_code)) {
		$course_info = api_get_course_info($course_code);
		$dbTable     = Database::get_course_table(TABLE_DOCUMENT,$course_info['dbName']);
	}
	$path = Database::escape_string($path);
	$query = "select comment from $dbTable where path='$path'";
	$result = Database::query($query);

	while ($row = Database::fetch_array($result)) {
		return $row[0];
	}
	return "";
}

/**
 * Sets the comment in the database for a particular path
 * @param	string	File path
 * @param	string	Comment to set
 * @return	string	Result of the database operation (Database::query will output some message directly on error anyway)
 */
function SetComment($path,$comment) {
	global $dbTable;
	$path = Database::escape_string($path);
	$comment = Database::escape_string($comment);
	$query = "UPDATE $dbTable set comment='$comment' where path='$path'";
	$result = Database::query($query);
	return "$result";
}

/**
 * Reads the file contents into a string
 * @param	string	Urlencoded path
 * @return	string	The file contents or false on security error
 */
function ReadFileCont($full_file_path) {
    if (Security::check_abs_path(dirname($full_file_path).'/',api_get_path(SYS_COURSE_PATH))) {
        if (is_file($full_file_path)) {
        	if (!($fp = fopen(urldecode($full_file_path), "r"))) {
        		return "";
        	}
        	$contents = fread($fp, filesize($full_file_path));
        	fclose($fp);
        	return $contents;
        }
    }
    return false;
}

/**
 * Writes the file contents into the given filepath
 * @param	string	Urlencoded path
 * @param 	string	The file contents
 * @return  boolean True on success, false on security error
 */
function WriteFileCont($full_file_path,$content) {
    // check if this is not an attack, trying to get into other directories or something like that
    global $_course;
    if (Security::check_abs_path(dirname($full_file_path).'/',api_get_path(SYS_COURSE_PATH).$_course['path'].'/')) {
        // check if this is not an attack, trying to upload a php file or something like that
        if (basename($full_file_path) != Security::filter_filename(basename($full_file_path))) { return false; }
        if (!($fp = fopen(urldecode($full_file_path), "w"))) {
    		//die("could not open Quiz input");
    	}
    	fwrite($fp,$content);
    	fclose($fp);
        return true;
    }
    return false;
}

/**
 * Gets the name of an img whose path is given (without directories or extensions)
 * @param	string	An image tag (<img src="...." ...>)
 * @return	string	The image file name or an empty string
 */
function GetImgName($imgtag) {
    // select src tag from img tag
	$match = array();
	//preg_match('/(src=(["\'])1.*(["\'])1)/i',$imgtag,$match);  		  //src
	preg_match('/src(\s)*=(\s)*[\'"]([^\'"]*)[\'"]/i',$imgtag,$match); //get the img src as contained between " or '
	//list($key,$srctag)=each($match);
	$src=$match[3];
	//$src = substr($srctag,5,(strlen($srctag)-7));
	if (stristr($src,"http")===false) {
    // valid or invalid image name
		if ($src=="") {
			return "";
		} else {
			$tmp_src = basename($src) ;
			if ($tmp_src == "") {
				return $src;
			} else {
				return $tmp_src;
			}
		}
	} else {
        //the img tag contained "http", which means it is probably external. Ignore it.
		return "";
	}
}

/**
 * Gets the source path of an image tag
 * @param	string	An image tag
 * @return	string	The image source or ""
 */
function GetSrcName($imgtag) {
    // select src tag from img tag
	$match = array();
	preg_match("|(src=\".*\" )|U",$imgtag,$match);  		  //src
	list($key,$srctag)=each($match);
	$src = substr($srctag,5,(strlen($srctag)-7));
	if (stristr($src,"http")==false) {
    // valid or invalid image name
		return $src;
	} else {
		return '';
	}
}

/**
 * Gets the image parameters from an image path
 * @param	string	File name
 * @param	string	File path
 * @param  reference	Reference to a list of image parameters (emptied, then used to return results)
 * @param	reference	Reference to a counter of images (emptied, then used to return results)
 */
function GetImgParams($fname,$fpath,&$imgparams,&$imgcount) {
    //select img tags from context
	$imgparams = array();
	//phpinfo();
	$contents = ReadFileCont("$fpath"."$fname");
	$matches = array();
	preg_match_all("(<img .*>)",$contents,$matches);
	$imgcount = 0;
	while (list($int,$match)=each($matches)) {
		//each match consists of a key and a value
		while (list($key,$imgtag)=each($match)) {
			$imgname = GetImgName($imgtag);
			if ($imgname!="" && !in_array($imgname,$imgparams)) {
				array_push($imgparams,$imgname);  // name (+ type) of the images in the html test
				$imgcount = $imgcount + 1;   			// number of images in the html test
			}
		}
	}
}

/**
 * Generates a list of hidden fields with the image params given as parameter to this function
 * @param	array		List of image parameters
 * @return	string	String containing the hidden parameters built from the list given
 */
function GenerateHiddenList($imgparams) {
	$list = "";
	if (is_array($imgparams)) {
        while (list($int,$string)=each($imgparams)) {
			$list .= "<input type=\"hidden\" name=\"imgparams[]\" value=\"$string\" />\n";
		}
	}
	return $list;
}

/**
 * Searches for a node in the given array
 * @param	reference	Reference to the array to search
 * @param	string		Node we are looking for in the array
 * @return	mixed			Node name or false if not found
 */
function myarraysearch(&$array,$node) {
	$match = FALSE;
	$tmp_array = array();
	for($i=0;$i<count($array);$i++) {
		if (!strcmp($array[$i],$node)) {
			$match = $node;
		} else {
            array_push($tmp_array,$array[$i]);
        }
	}
	$array = $tmp_array;
	return $match;
}

/**
 * Look for the image name into an array
 * @param	reference	Reference to an array to search
 * @param	string		String to look for
 * @return	mixed			String given if found, false otherwise
 * @uses		myarraysearch	This function is just an additional layer on the myarraysearch() function
 */
function CheckImageName(&$imgparams,$string)
{
	$checked = myarraysearch($imgparams,$string);
	return $checked;
}

/**
 * Replaces an image tag by ???
 * @param	string	The content to replace
 * @return	string	The modified content
 */
function ReplaceImgTag($content) {
	$newcontent = $content;
	$matches = array();
	preg_match_all("(<img .*>)",$content,$matches);
	$imgcount = 0;
	while (list($int,$match)=each($matches)) {
		while (list($key,$imgtag)=each($match)) {
			$imgname = GetSrcName($imgtag);
			if ($imgname=="") {}								// valid or invalid image name
			else {

				$prehref = $imgname;
				$posthref = basename($imgname);
				$newcontent = str_replace($prehref,$posthref,$newcontent);
			}
		}
	}
	return $newcontent;
}

/**
 * Fills the folder name up to a certain length with "0"
 * @param	string	Original folder name
 * @param	integer	Length to reach
 * @return	string	Modified folder name
 */
function FillFolderName($name,$nsize) {
	$str = "";
	for($i=0;$i < $nsize-strlen($name);$i++) {
		$str .= "0";
	}
	$str .= $name;
	return $str;
}

/**
 * Generates the HotPotato folder tree
 * @param	string	Folder path
 * @return	string	Folder name (modified)
 */
function GenerateHpFolder($folder) {
	$filelist = array();
	if ($dir = @opendir($folder)) {
		while (($file = readdir($dir)) !== false) {
			if ( $file != ".") {
				if ($file != "..") {
					$full_name = $folder."/".$file;
					if (is_dir($full_name)) {
						$filelist[] = $file;
					}
			   }
			}
		}
	}
	$w = 0;
	do {
		$name = FillFolderName(mt_rand(1,99999),6);
		$checked = myarraysearch($filelist,$name);
		//as long as we find the name in the array, continue looping. As soon as we have a new element, quit
		if ($checked) { $w = 1;	}
		else { $w = 0; }
	} while ($w==1);

	return $name;
}

/**
 * Gets the folder name (strip down path)
 * @param	string	Path
 *	@return	string	Folder name stripped down
 */
function GetFolderName($fname) {
	$name = explode('/',$fname);
	$name = $name[sizeof($name)-2];
	return $name;
}

/**
 * Gets the folder path (withouth the name of the folder itself) ?
 * @param	string	Path
 * @return	string	Path stripped down
 */
function GetFolderPath($fname) {
	$str = "";
	$name = explode('/',$fname);
	for ($i=0;$i < sizeof($name)-1; $i++) {
        $str = $str.$name[$i]."/";
    }
	return $str;
}

/**
 * Checks if there are subfolders
 * @param	string	Path
 * @return	integer	1 if a subfolder was found, 0 otherwise
 */
function CheckSubFolder($path) {
	$folder = GetFolderPath($path);
	$dflag = 0;
	if ($dir = @opendir($folder)) {
		while (($file = readdir($dir)) !== false) {
			if ( $file != ".") {
				if ($file != "..") {
					$full_name = $folder."/".$file;
					if (is_dir($full_name)) {
						$dflag = 1;	// first directory
					}
				}
			}
		}
	}
	return $dflag;
}

/**
 * Hotpotato Garbage Collector
 * @param	string	Path
 * @param	integer	Flag
 * @param	integer	User id
 * @return	void	No return value, but echoes results
 */
function HotPotGCt($folder,$flag,$userID) {
    // Garbage Collector
	$filelist = array();
	if ($dir = @opendir($folder)) {
		while (($file = readdir($dir)) !== false) {
			if ( $file != ".") {
				if ($file != "..") {
					$full_name = $folder."/".$file;
					if (is_dir($full_name)) {
						HotPotGCt($folder."/".$file,$flag,$userID);
					} else {
						$filelist[] = $file;
					}
			   }
			}
		}
		closedir($dir);
	}
	while (list ($key, $val) = each ($filelist)) {
		if (stristr($val,$userID.".t.html")) {
			if ($flag == 1) {
				my_delete($folder."/".$val);
			} else {
				echo $folder."/".$val."<br />";
			}
		}
	}
}