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     $nomoodlecookie = true;     // Because it interferes with caching
   7
   8     require_once('../../config.php');
   9
  10     if (empty($CFG->textfilters)) {
  11         error ('Filter not enabled!');
  12     } else {
  13         $filters = explode(',', $CFG->textfilters);
  14         if (array_search('filter/algebra', $filters) === FALSE) {
  15             error ('Filter not enabled!');
  16         }
  17     }
  18
  19     // disable moodle specific debug messages
  20     disable_debugging();
  21
  22     require_once($CFG->libdir.'/filelib.php');
  23
  24     $CFG->texfilterdir     = 'filter/tex';
  25     $CFG->algebrafilterdir = 'filter/algebra';
  26     $CFG->algebraimagedir  = 'filter/algebra';
  27
  28
  29     $cmd    = '';               // Initialise these variables
  30     $status = '';
  31
  32     //error_reporting(E_ALL);
  33
  34     $relativepath = get_file_argument('pix.php');
  35
  36     $args = explode('/', trim($relativepath, '/'));
  37
  38     if (count($args) == 1) {
  39         $image    = $args[0];
  40         $pathname = $CFG->dataroot.'/'.$CFG->algebraimagedir.'/'.$image;
  41     } else {
  42         error('No valid arguments supplied');
  43     }
  44
  45     if (!file_exists($pathname)) {
  46         $md5 = str_replace('.gif','',$image);
  47         if ($texcache = get_record('cache_filters', 'filter', 'algebra', 'md5key', $md5)) {
  48             if (!file_exists($CFG->dataroot.'/'.$CFG->algebraimagedir)) {
  49                 make_upload_directory($CFG->algebraimagedir);
  50             }
  51
  52             $texexp = $texcache->rawtext;
  53             $texexp = str_replace('&lt;','<',$texexp);
  54             $texexp = str_replace('&gt;','>',$texexp);
  55             $texexp = preg_replace('!\r\n?!',' ',$texexp);
  56             $texexp = '\Large ' . $texexp;
  57             $texexp = escapeshellarg($texexp);
  58
  59             if ((PHP_OS == "WINNT") || (PHP_OS == "WIN32") || (PHP_OS == "Windows")) {
  60                 $cmd = "$CFG->dirroot/$CFG->texfilterdir/mimetex.exe";
  61                 $cmd = str_replace(' ','^ ',$cmd);
  62                 $cmd .= " ++ -e  \"$pathname\" -- $texexp";
  63             } else if (is_executable("$CFG->dirroot/$CFG->texfilterdir/mimetex")) {   /// Use the custom binary
  64
  65                 $cmd = "$CFG->dirroot/$CFG->texfilterdir/mimetex -e $pathname -- $texexp";
  66
  67             } else {                                                           /// Auto-detect the right TeX binary
  68                 switch (PHP_OS) {
  69
  70                     case "Linux":
  71                         $cmd = "\"$CFG->dirroot/$CFG->texfilterdir/mimetex.linux\" -e \"$pathname\" -- $texexp";
  72                     break;
  73
  74                     case "Darwin":
  75                         $cmd = "\"$CFG->dirroot/$CFG->texfilterdir/mimetex.darwin\" -e \"$pathname\" -- $texexp";
  76                     break;
  77
  78                     default:      /// Nothing was found, so tell them how to fix it.
  79                         if (debugging()) {
  80                             echo "Make sure you have an appropriate MimeTeX binary here:\n\n";
  81                             echo "    $CFG->dirroot/$CFG->texfilterdir/mimetex\n\n";
  82                             echo "and that it has the right permissions set on it as executable program.\n\n";
  83                             echo "You can get the latest binaries for your ".PHP_OS." platform from: \n\n";
  84                             echo "    http://moodle.org/download/mimetex/";
  85                         } else {
  86                             echo "Mimetex executable was not found,\n";
  87                             echo "Please turn on debug mode in site configuration to see more info here.";
  88                         }
  89                         die;
  90                     break;
  91                 }
  92             }
  93             system($cmd, $status);
  94         }
  95     }
  96
  97     if (file_exists($pathname)) {
  98         send_file($pathname, $image);
  99     } else {
 100         if (debugging()) {
 101             echo "The shell command<br />$cmd<br />returned status = $status<br />\n";
 102             echo "Image not found!<br />";
 103             echo "Please try the <a href=\"$CFG->wwwroot/$CFG->algebrafilterdir/algebradebug.php\">debugging script</a>";
 104         } else {
 105             echo "Image not found!<br />";
 106             echo "Please try the <a href=\"$CFG->wwwroot/$CFG->algebrafilterdir/algebradebug.php\">debugging script</a><br />";
 107             echo "Please turn on debug mode in site configuration to see more info here.";
 108         }
 109     }
 110 ?>