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1 <?php 2 // This file is part of Moodle - http://moodle.org/ 3 // 4 // Moodle is free software: you can redistribute it and/or modify 5 // it under the terms of the GNU General Public License as published by 6 // the Free Software Foundation, either version 3 of the License, or 7 // (at your option) any later version. 8 // 9 // Moodle is distributed in the hope that it will be useful, 10 // but WITHOUT ANY WARRANTY; without even the implied warranty of 11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 // GNU General Public License for more details. 13 // 14 // You should have received a copy of the GNU General Public License 15 // along with Moodle. If not, see <http://www.gnu.org/licenses/>. 16 17 /** 18 * This function fetches math. images from the data directory 19 * If not, it obtains the corresponding TeX expression from the cache_tex db table 20 * and uses mimeTeX to create the image file 21 * 22 * @package filter 23 * @subpackage tex 24 * @copyright 2004 Zbigniew Fiedorowicz [email protected] 25 * Originally based on code provided by Bruno Vernier [email protected] 26 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later 27 */ 28 29 require_once("../../config.php"); 30 31 if (!filter_is_enabled('tex')) { 32 print_error('filternotenabled'); 33 } 34 35 require_once($CFG->libdir.'/filelib.php'); 36 require_once($CFG->dirroot.'/filter/tex/lib.php'); 37 require_once($CFG->dirroot.'/filter/tex/latex.php'); 38 39 $action = optional_param('action', '', PARAM_ALPHA); 40 $texexp = optional_param('tex', '', PARAM_RAW); 41 42 require_login(); 43 require_capability('moodle/site:config', context_system::instance(), $USER->id); /// Required cap to run this. MDL-18552 44 45 $output = ''; 46 47 // look up in cache if required 48 if ($action=='ShowDB' or $action=='DeleteDB') { 49 $md5 = md5($texexp); 50 $texcache = $DB->get_record("cache_filters", array("filter"=>"tex", "md5key"=>$md5)); 51 } 52 53 // Action: Show DB Entry 54 if ($action=='ShowDB') { 55 if ($texcache) { 56 $output = "DB cache_filters entry for $texexp\n"; 57 $output .= "id = $texcache->id\n"; 58 $output .= "filter = $texcache->filter\n"; 59 $output .= "version = $texcache->version\n"; 60 $output .= "md5key = $texcache->md5key\n"; 61 $output .= "rawtext = $texcache->rawtext\n"; 62 $output .= "timemodified = $texcache->timemodified\n"; 63 } else { 64 $output = "DB cache_filters entry for $texexp not found\n"; 65 } 66 } 67 68 // Action: Delete DB Entry 69 if ($action=='DeleteDB') { 70 if ($texcache) { 71 $output = "Deleting DB cache_filters entry for $texexp\n"; 72 $result = $DB->delete_records("cache_filters", array("id"=>$texcache->id)); 73 if ($result) { 74 $result = 1; 75 } else { 76 $result = 0; 77 } 78 $output .= "Number of records deleted = $result\n"; 79 } else { 80 $output = "Could not delete DB cache_filters entry for $texexp\nbecause it could not be found.\n"; 81 } 82 } 83 84 // Action: Show Image 85 if ($action=='ShowImageMimetex') { 86 tex2image($texexp); 87 } 88 89 // Action: Check Slasharguments 90 if ($action=='SlashArguments') { 91 slasharguments($texexp); 92 } 93 94 // Action: Show Tex command line output 95 if ($action=='ShowImageTex') { 96 TexOutput($texexp, true); 97 exit; 98 } 99 100 // Action: Show Tex command line output 101 if ($action=='ShowOutputTex') { 102 if (debugging()) { 103 TexOutput($texexp); 104 } else { 105 echo "Can not output detailed information due to security concerns, please turn on debug mode first."; 106 } 107 exit; 108 } 109 110 if (!empty($action)) { 111 outputText($output); 112 } 113 114 // nothing more to do if there was any action 115 if (!empty($action)) { 116 exit; 117 } 118 119 120 function outputText($texexp) { 121 header("Content-type: text/html; charset=utf-8"); 122 echo "<html><body><pre>\n"; 123 if ($texexp) { 124 echo s($texexp)."\n\n"; 125 } else { 126 echo "No text output available\n\n"; 127 } 128 echo "</pre></body></html>\n"; 129 } 130 131 function tex2image($texexp, $return=false) { 132 global $CFG; 133 134 if (!$texexp) { 135 echo 'No tex expresion specified'; 136 return; 137 } 138 139 $image = md5($texexp) . ".gif"; 140 $filetype = 'image/gif'; 141 if (!file_exists("$CFG->dataroot/filter/tex")) { 142 make_upload_directory("filter/tex"); 143 } 144 $pathname = "$CFG->dataroot/filter/tex/$image"; 145 if (file_exists($pathname)) { 146 unlink($pathname); 147 } 148 149 $texexp = '\Large '.$texexp; 150 $commandpath = filter_tex_get_executable(true); 151 $cmd = filter_tex_get_cmd($pathname, $texexp); 152 system($cmd, $status); 153 154 if ($return) { 155 return $image; 156 } 157 158 if (file_exists($pathname)) { 159 send_file($pathname, $image); 160 161 } else if (debugging()) { 162 $ecmd = "$cmd 2>&1"; 163 echo `$ecmd` . "<br />\n"; 164 echo "The shell command<br />$cmd<br />returned status = $status<br />\n"; 165 if ($status == 4) { 166 echo "Status corresponds to illegal instruction<br />\n"; 167 } else if ($status == 11) { 168 echo "Status corresponds to bus error<br />\n"; 169 } else if ($status == 22) { 170 echo "Status corresponds to abnormal termination<br />\n"; 171 } 172 if (file_exists($commandpath)) { 173 echo "File size of mimetex executable $commandpath is " . filesize($commandpath) . "<br />"; 174 echo "The file permissions are: " . decoct(fileperms($commandpath)) . "<br />"; 175 if (function_exists("md5_file")) { 176 echo "The md5 checksum of the file is " . md5_file($commandpath) . "<br />"; 177 } else { 178 $handle = fopen($commandpath,"rb"); 179 $contents = fread($handle,16384); 180 fclose($handle); 181 echo "The md5 checksum of the first 16384 bytes is " . md5($contents) . "<br />"; 182 } 183 } else { 184 echo "mimetex executable $commandpath not found!<br />"; 185 } 186 echo "Image not found!"; 187 } else { 188 echo "Can not output detailed information due to security concerns, please turn on debug mode first."; 189 } 190 } 191 192 193 // test Tex/Ghostscript output - command execution only 194 function TexOutput($expression, $graphic=false) { 195 global $CFG; 196 $output = ''; 197 198 $latex = new latex(); 199 200 // first check if it is likely to work at all 201 $output .= "<h3>Checking executables</h3>\n"; 202 $executablesexist = true; 203 $pathlatex = trim(get_config('filter_tex', 'pathlatex'), " '\""); 204 if (is_file($pathlatex)) { 205 $output .= "latex executable ($pathlatex) is readable<br />\n"; 206 } else { 207 $executablesexist = false; 208 $output .= "<b>Error:</b> latex executable ($pathlatex) is not readable<br />\n"; 209 } 210 $pathdvips = trim(get_config('filter_tex', 'pathdvips'), " '\""); 211 if (is_file($pathdvips)) { 212 $output .= "dvips executable ($pathdvips) is readable<br />\n"; 213 } else { 214 $executablesexist = false; 215 $output .= "<b>Error:</b> dvips executable ($pathdvips) is not readable<br />\n"; 216 } 217 $pathconvert = trim(get_config('filter_tex', 'pathconvert'), " '\""); 218 if (is_file($pathconvert)) { 219 $output .= "convert executable ($pathconvert) is readable<br />\n"; 220 } else { 221 $executablesexist = false; 222 $output .= "<b>Error:</b> convert executable ($pathconvert) is not readable<br />\n"; 223 } 224 $pathdvisvgm = trim(get_config('filter_tex', 'pathdvisvgm'), " '\""); 225 if (is_file($pathdvisvgm)) { 226 $output .= "dvisvgm executable ($pathdvisvgm) is readable<br />\n"; 227 } else { 228 $executablesexist = false; 229 $output .= "<b>Error:</b> dvisvgm executable ($pathdvisvgm) is not readable<br />\n"; 230 } 231 232 // knowing that it might work.. 233 $md5 = md5($expression); 234 $output .= "<p>base filename for expression is '$md5'</p>\n"; 235 236 // temporary paths 237 $tex = "$latex->temp_dir/$md5.tex"; 238 $dvi = "$latex->temp_dir/$md5.dvi"; 239 $ps = "$latex->temp_dir/$md5.ps"; 240 $convertformat = get_config('filter_tex', 'convertformat'); 241 $img = "$latex->temp_dir/$md5.{$convertformat}"; 242 243 // put the expression as a file into the temp area 244 $expression = html_entity_decode($expression); 245 $output .= "<p>Processing TeX expression:</p><pre>$expression</pre>\n"; 246 $doc = $latex->construct_latex_document($expression); 247 $fh = fopen($tex, 'w'); 248 fputs($fh, $doc); 249 fclose($fh); 250 251 // cd to temp dir 252 chdir($latex->temp_dir); 253 254 // step 1: latex command 255 $pathlatex = escapeshellarg($pathlatex); 256 $cmd = "$pathlatex --interaction=nonstopmode --halt-on-error $tex"; 257 $output .= execute($cmd); 258 259 // step 2: dvips command 260 $pathdvips = escapeshellarg($pathdvips); 261 $cmd = "$pathdvips -E $dvi -o $ps"; 262 $output .= execute($cmd); 263 264 // Step 3: Set convert or dvisvgm command. 265 if ($convertformat == 'svg') { 266 $pathdvisvgm = escapeshellarg($pathdvisvgm); 267 $cmd = "$pathdvisvgm -E $ps -o $img"; 268 } else { 269 $pathconvert = escapeshellarg($pathconvert); 270 $cmd = "$pathconvert -density 240 -trim $ps $img "; 271 } 272 $output .= execute($cmd); 273 274 if (!$graphic) { 275 echo $output; 276 } else if (file_exists($img)) { 277 send_file($img, "$md5.{$convertformat}"); 278 } else { 279 echo "Error creating image, see command execution output for more details."; 280 } 281 } 282 283 function execute($cmd) { 284 exec($cmd, $result, $code); 285 $output = "<pre>$ $cmd\n"; 286 $lines = implode("\n", $result); 287 $output .= "OUTPUT: $lines\n"; 288 $output .= "RETURN CODE: $code\n</pre>\n"; 289 return $output; 290 } 291 292 function slasharguments($texexp) { 293 global $CFG; 294 $admin = $CFG->wwwroot.'/'.$CFG->admin.'/settings.php?section=http'; 295 $image = tex2image($texexp,true); 296 echo "<p>If the following image displays correctly, set your "; 297 echo "<a href=\"$admin\" target=\"_blank\">Administration->Server->HTTP</a> "; 298 echo "setting for slasharguments to file.php/1/pic.jpg: "; 299 echo "<img src=\"$CFG->wwwroot/filter/tex/pix.php/$image\" align=\"absmiddle\"></p>\n"; 300 echo "<p>Otherwise set it to file.php?file=/1/pic.jpg "; 301 echo "It should display correctly as "; 302 echo "<img src=\"$CFG->wwwroot/filter/tex/pix.php?file=$image\" align=\"absmiddle\"></p>\n"; 303 echo "<p>If neither equation image displays correctly, please seek "; 304 echo "further help at moodle.org at the "; 305 echo "<a href=\"http://moodle.org/mod/forum/view.php?id=752&loginguest=true\" target=\"_blank\">"; 306 echo "Mathematics Tools Forum</a></p>"; 307 } 308 309 ?> 310 311 <html> 312 <head><title>TeX Filter Debugger</title></head> 313 <body> 314 <p>Please enter an algebraic expression <b>without</b> any surrounding $$ into 315 the text box below. (Click <a href="#help">here for help.</a>) 316 <form action="texdebug.php" method="get" 317 target="inlineframe"> 318 <center> 319 <input type="text" name="tex" size="50" 320 value="f(x)=\int_{-\infty}^x~e^{-t^2}dt" /> 321 </center> 322 <p>The following tests are available:</p> 323 <ol> 324 <li><input type="radio" name="action" value="ShowDB" id="ShowDB" /> 325 <label for="ShowDB">See the cache_filters database entry for this expression (if any).</label></li> 326 <li><input type="radio" name="action" value="DeleteDB" id="DeleteDB" /> 327 <label for="DeleteDB">Delete the cache_filters database entry for this expression (if any).</label></li> 328 <li><input type="radio" name="action" value="ShowImageMimetex" id="ShowImageMimetex" checked="checked" /> 329 <label for="ShowImageMimetex">Show a graphic image of the algebraic expression rendered with mimetex.</label></li> 330 <li><input type="radio" name="action" value="ShowImageTex" id="ShowImageTex" /> 331 <label for="ShowImageTex">Show a graphic image of the algebraic expression rendered with Tex/Ghostscript.</label></li> 332 <li><input type="radio" name="action" value="ShowOutputTex" id="ShowOutputTex" /> 333 <label for="ShowOutputTex">Show command execution output from the algebraic expression rendered with Tex/Ghostscript.</label></li> 334 <li><input type="radio" name="action" value="SlashArguments" id="SlashArguments" /> 335 <label for="SlashArguments">Check slasharguments setting.</label></li> 336 </ol> 337 <input type="submit" value="Do it!" /> 338 </form> <br /> <br /> 339 <center> 340 <iframe name="inlineframe" align="middle" width="80%" height="200"> 341 <p>Something is wrong...</p> 342 </iframe> 343 </center> <br /> 344 <hr /> 345 <a name="help"> 346 <h2>Debugging Help</h2> 347 </a> 348 <p>First a brief overview of how the TeX filter works. The TeX filter first 349 searches the database cache_filters table to see if this TeX expression had been 350 processed before. If not, it adds a DB entry for that expression. It then 351 replaces the TeX expression by an <img src=".../filter/tex/pix.php..."> 352 tag. The filter/tex/pix.php script then searches the database to find an 353 appropriate gif/png/svg image file for that expression and to create one if it doesn't exist. 354 It will then use either the LaTex/Ghostscript renderer (using external executables 355 on your system) or the bundled Mimetex executable. The full Latex/Ghostscript 356 renderer produces better results and is tried first. 357 Here are a few common things that can go wrong and some suggestions on how 358 you might try to fix them.</p> 359 <ol> 360 <li>Something had gone wrong on a previous occasion when the filter tried to 361 process this expression. Then the database entry for that expression contains 362 a bad TeX expression in the rawtext field (usually blank). You can fix this 363 by clicking on "Delete DB Entry"</li> 364 <li>The TeX to gif/png/svg image conversion process does not work. 365 If paths are specified in the filter configuation screen for the three 366 executables these will be tried first. Note that they still must be correctly 367 installed and have the correct permissions. In particular make sure that you 368 have all the packages installed (e.g., on Debian/Ubuntu you need to install 369 the 'tetex-extra' package). Running the 'show command execution' test should 370 give a big clue. 371 If this fails or is not available, the Mimetex executable is tried. If this 372 fails a likely cause is that the mimetex binary you are using is 373 incompatible with your operating system. You can try compiling it from the 374 C sources downloaded from <a href="http://www.forkosh.com/mimetex.zip"> 375 http://www.forkosh.com/mimetex.zip</a>, or looking for an appropriate 376 binary at <a href="http://moodle.org/download/mimetex/"> 377 http://moodle.org/download/mimetex/</a>. You may then also need to 378 edit your moodle/filter/tex/pix.php file to add 379 <br /><?php echo "case "" . PHP_OS . "":" ;?><br ?> to the list of operating systems 380 in the switch (PHP_OS) statement. Windows users may have a problem properly 381 unzipping mimetex.exe. Make sure that mimetex.exe is is <b>PRECISELY</b> 382 433152 bytes in size. If not, download a fresh copy from 383 <a href="http://moodle.org/download/mimetex/windows/mimetex.exe"> 384 http://moodle.org/download/mimetex/windows/mimetex.exe</a>. 385 Another possible problem which may affect 386 both Unix and Windows servers is that the web server doesn't have execute permission 387 on the mimetex binary. In that case change permissions accordingly</li> 388 </ol> 389 </body> 390 </html>
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