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     $cmd = '';      // Initialise these variables
  15     $status = '';
  16
  17     error_reporting(E_ALL);
  18
  19     $lifetime = 86400;
  20     if (isset($file)) {     // workaround for situations where / syntax doesn't work
  21         $pathinfo = '/' . $file;
  22     } else {
  23         $pathinfo = get_slash_arguments("pix.php");
  24     }
  25
  26     if (! $args = parse_slash_arguments($pathinfo)) {
  27         error("No valid arguments supplied");
  28     }
  29
  30     $numargs = count($args);
  31
  32     if ($numargs == 1) {
  33         $image  = $args[0];
  34         $pathname = "$CFG->dataroot/$CFG->algebraimagedir/$image";
  35         $filetype = "image/gif";
  36     } else {
  37         error("No valid arguments supplied");
  38     }
  39
  40
  41     if (!file_exists($pathname)) {
  42         $md5 = str_replace('.gif','',$image);
  43         if ($texcache = get_record("cache_filters", "filter", "algebra", "md5key", $md5)) {
  44             if (!file_exists("$CFG->dataroot/$CFG->algebraimagedir")) {
  45                 make_upload_directory($CFG->algebraimagedir);
  46             }
  47
  48             $texexp = $texcache->rawtext;
  49             $texexp = str_replace('&lt;','<',$texexp);
  50             $texexp = str_replace('&gt;','>',$texexp);
  51             $texexp = preg_replace('!\r\n?!',' ',$texexp);
  52             $texexp = '\Large ' . $texexp;
  53
  54             if ((PHP_OS == "WINNT") || (PHP_OS == "WIN32") || (PHP_OS == "Windows")) {
  55                 $texexp = str_replace('"','\"',$texexp);
  56                 $cmd = "$CFG->dirroot/$CFG->texfilterdir/mimetex.exe";
  57                 $cmd = str_replace(' ','^ ',$cmd);
  58                 $cmd .= " ++ -e  \"$pathname\" \"$texexp\"";
  59             } else if (is_executable("$CFG->dirroot/$CFG->texfilterdir/mimetex")) {   /// Use the custom binary
  60
  61                 $cmd = "$CFG->dirroot/$CFG->texfilterdir/mimetex -e $pathname ". escapeshellarg($texexp);
  62
  63             } else {                                                           /// Auto-detect the right TeX binary
  64                 switch (PHP_OS) {
  65
  66                     case "Linux":
  67                         $cmd = "\"$CFG->dirroot/$CFG->texfilterdir/mimetex.linux\" -e \"$pathname\" ". escapeshellarg($texexp);
  68                     break;
  69
  70                     case "Darwin":
  71                         $cmd = "\"$CFG->dirroot/$CFG->texfilterdir/mimetex.darwin\" -e \"$pathname\" ". escapeshellarg($texexp);
  72                     break;
  73
  74                     default:      /// Nothing was found, so tell them how to fix it.
  75                         echo "Make sure you have an appropriate MimeTeX binary here:\n\n";
  76                         echo "    $CFG->dirroot/$CFG->texfilterdir/mimetex\n\n";
  77                         echo "and that it has the right permissions set on it as executable program.\n\n";
  78                         echo "You can get the latest binaries for your ".PHP_OS." platform from: \n\n";
  79                         echo "    http://moodle.org/download/mimetex/";
  80                         exit;
  81                     break;
  82                 }
  83             }
  84             system($cmd, $status);
  85         }
  86     }
  87
  88     if (file_exists($pathname)) {
  89         $lastmodified = filemtime($pathname);
  90         header("Last-Modified: " . gmdate("D, d M Y H:i:s", $lastmodified) . " GMT");
  91         header("Expires: " . gmdate("D, d M Y H:i:s", time() + $lifetime) . " GMT");
  92         header("Cache-control: max_age = $lifetime"); // a day
  93         header("Pragma: ");
  94         header("Content-disposition: inline; filename=$image");
  95         header("Content-length: ".filesize($pathname));
  96         header("Content-type: $filetype");
  97         readfile("$pathname");
  98     } else {
  99         echo "The shell command<br>$cmd<br>returned status = $status<br>\n";
 100         echo "Image not found!<br>";
 101         echo "Please try the <a href=\"$CFG->wwwroot/filter/algebra/algebradebug.php\">debugging script</a>";
 102     }
 103
 104     exit;
 105 ?>