filter/algebra/pix.php

   1 <?PHP // $Id$
   2       // This function fetches math. images from the data directory
   3       // If not, it obtains the corresponding TeX expression from the cache_tex db table
   4       // and uses mimeTeX to create the image file
   5
   6     $nomoodlecookie = true;     // Because it interferes with caching
   7
   8     require_once("../../config.php");
   9
  10     $CFG->algebrafilterdir = "filter/algebra";
  11     $CFG->texfilterdir = "filter/tex";
  12     $CFG->algebraimagedir = "filter/algebra";
  13
  14     error_reporting(E_ALL);
  15
  16     $lifetime = 86400;
  17     if (isset($file)) {     // workaround for situations where / syntax doesn't work
  18         $pathinfo = '/' . $file;
  19     } else {
  20         $pathinfo = get_slash_arguments("pix.php");
  21     }
  22
  23     if (! $args = parse_slash_arguments($pathinfo)) {
  24         error("No valid arguments supplied");
  25     }
  26
  27     $numargs = count($args);
  28
  29     if ($numargs == 1) {
  30         $image  = $args[0];
  31         $pathname = "$CFG->dataroot/$CFG->algebraimagedir/$image";
  32         $filetype = "image/gif";
  33     } else {
  34         error("No valid arguments supplied");
  35     }
  36
  37
  38     if (!file_exists($pathname)) {
  39         $md5 = str_replace('.gif','',$image);
  40         if ($texcache = get_record("cache_filters", "filter", "algebra", "md5key", $md5)) {
  41             if (!file_exists("$CFG->dataroot/$CFG->algebraimagedir")) {
  42                 make_upload_directory($CFG->algebraimagedir);
  43             }
  44
  45             $texexp = $texcache->rawtext;
  46             $texexp = str_replace('&lt;','<',$texexp);
  47             $texexp = str_replace('&gt;','>',$texexp);
  48             $texexp = preg_replace('!\r\n?!',' ',$texexp);
  49             $texexp = '\Large ' . $texexp;
  50             switch (PHP_OS) {
  51                 case "Linux":
  52                     $cmd = "\"$CFG->dirroot/$CFG->texfilterdir/mimetex.linux\" -e \"$pathname\" ". escapeshellarg($texexp);
  53                 break;
  54                 case "WINNT":
  55                 case "WIN32":
  56                 case "Windows":
  57                     $texexp = str_replace('"','\"',$texexp);
  58                     $cmd = "$CFG->dirroot/$CFG->texfilterdir/mimetex.exe";
  59                     $cmd = str_replace(' ','^ ',$cmd);
  60                     $cmd .= " ++ -e  \"$pathname\" \"$texexp\"";
  61                 break;
  62                 case "Darwin":
  63                     $cmd = "\"$CFG->dirroot/$CFG->texfilterdir/mimetex.darwin\" -e \"$pathname\" ". escapeshellarg($texexp);
  64                 break;
  65               default:      /// To allow drop-in binaries for other platforms
  66                if (!is_executable("$CFG->dirroot/$CFG->texfilterdir/mimetex")) {
  67                 echo "Make sure you have an appropriate MimeTeX binary here:\n\n";
  68                 echo "    $CFG->dirroot/$CFG->texfilterdir/mimetex\n\n";
  69                 echo "and that it has the right permissions set on it as executable program.\n\n";
  70                 echo "You can get the latest binaries for your ".PHP_OS." platform from: \n\n";
  71                 echo "    http://moodle.org/download/mimetex/";
  72                 exit;
  73               }
  74               $cmd = "$CFG->dirroot/$CFG->texfilterdir/mimetex -e $pathname ". escapeshellarg($texexp);
  75               break;
  76             }
  77             system($cmd, $status);
  78         }
  79     }
  80
  81     if (file_exists($pathname)) {
  82         $lastmodified = filemtime($pathname);
  83         header("Last-Modified: " . gmdate("D, d M Y H:i:s", $lastmodified) . " GMT");
  84         header("Expires: " . gmdate("D, d M Y H:i:s", time() + $lifetime) . " GMT");
  85         header("Cache-control: max_age = $lifetime"); // a day
  86         header("Pragma: ");
  87         header("Content-disposition: inline; filename=$image");
  88         header("Content-length: ".filesize($pathname));
  89         header("Content-type: $filetype");
  90         readfile("$pathname");
  91     } else {
  92         echo "The shell command<br>$cmd<br>returned status = $status<br>\n";
  93         echo "Image not found!<br>";
  94         echo "Please try the <a href=\"$CFG->wwwroot/filter/algebra/algebradebug.php\">debugging script</a>";
  95     }
  96
  97     exit;
  98 ?>