Magic.php

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<?

/*

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

require "MagicConfig.php";

class Magic
{
        function Magic()
        {
                $this->config = new MagicConfig();
        }
        
        function load_file($filename)
        {
                if (!($filehandle = @fopen($filename, "rb"))) return undef;
                set_magic_quotes_runtime(0); 
                $text = fread($filehandle, filesize($filename));
                set_magic_quotes_runtime(get_magic_quotes_gpc());
                fclose($filehandle);
                return $text;
        }   

        function _is_ascii($file)
        {
                $arr = unpack("C*", $file);
                for($i=1; $i<sizeof($arr); $i++)
                {       
                        if ($arr[$i]<32 && $arr[$i]!=13 && $arr[$i]!=10) return false;
                }
                return true;
        }
        
        function get_language($filename)
        {
                // First attempt a match with the filename extension.
                $extensionspl = explode($this->config->separator, $filename);
                $extension = $extensionspl[sizeof($extensionspl)-1];
                $langstr = $this->config->extensions[$extension];
                // We may have a choice of languages, so check.
                $langarr = explode("|", $langstr);
                
                // Got one language? Good!
                if (sizeof($langarr)==1 && $langarr[0]!="") return $langstr;
                
                // Now the real magic starts :o) We may have a narrowed-down set of options from 
                // the tests above, which will speed things up a little.
                
                // Get one /big/ string.
                $this->config->file = $this->load_file($filename);
                if ($this->config->file == undef) return "illegal";
                $this->is_ascii = $this->_is_ascii($this->config->file);

                if (isset($langstr)) 
                {
                        // We don't know if all of the types are in our magic file, so filter out those that
                        // aren't.
                        
                        $outarray = array();
                        foreach($langarr as $lang)
                        {
                                if ($this->is_ascii && in_array($lang, $this->config->langfunctions))
                                        array_push($outarray, $lang);
                                else if(in_array($lang, $this->config->binfunctions))
                                        array_push($outarray, $lang);
                        }
                        $testarray = $outarray;
                }
                else 
                {
                        if ($this->is_ascii) $testarray = $this->config->langfunctions;
                                else $testarray = $this->config->binfunctions;
                }
                foreach($testarray as $test)
                {
                        $func = "detect_".$test;
                        if ($this->config->$func()) return $test;
                }
        }
}

?>