Search moodle.org's
Developer Documentation
Developer Documentation
- Bug fixes for general core bugs in 4.0.x will end 8 May 2023 (12 months).
- Bug fixes for security issues in 4.0.x will end 13 November 2023 (18 months).
- PHP version: minimum PHP 7.3.0 Note: the minimum PHP version has increased since Moodle 3.10. PHP 7.4.x is also supported.
/filter/algebra/ -> algebradebug.php (source)
Differences Between: [Versions 400 and 401] [Versions 400 and 402] [Versions 400 and 403]
1 <?php 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 require_once("../../config.php"); 7 8 if (!filter_is_enabled('algebra')) { 9 print_error('filternotenabled'); 10 } 11 12 require_once($CFG->libdir.'/filelib.php'); 13 require_once($CFG->dirroot.'/filter/tex/lib.php'); 14 15 $action = optional_param('action', '', PARAM_ALPHANUM); 16 $algebra = optional_param('algebra', '', PARAM_RAW); 17 18 require_login(); 19 require_capability('moodle/site:config', context_system::instance()); 20 if ($action || $algebra) { 21 require_sesskey(); 22 } 23 24 if ($algebra && $action) { 25 $md5 = md5($algebra); 26 if ($action == 'ShowDB' || $action == 'DeleteDB') { 27 $texcache = $DB->get_record("cache_filters", array("filter"=>"algebra", "md5key"=>$md5)); 28 } 29 if ($action == 'ShowDB') { 30 if ($texcache) { 31 $output = "DB cache_filters entry for $algebra\n"; 32 $output .= "id = $texcache->id\n"; 33 $output .= "filter = $texcache->filter\n"; 34 $output .= "version = $texcache->version\n"; 35 $output .= "md5key = $texcache->md5key\n"; 36 $output .= "rawtext = $texcache->rawtext\n"; 37 $output .= "timemodified = $texcache->timemodified\n"; 38 } else { 39 $output = "DB cache_filters entry for $algebra not found\n"; 40 } 41 } 42 if ($action == 'DeleteDB') { 43 if ($texcache) { 44 $output = "Deleting DB cache_filters entry for $algebra\n"; 45 $result = $DB->delete_records("cache_filters", array("id"=>$texcache->id)); 46 if ($result) { 47 $result = 1; 48 } else { 49 $result = 0; 50 } 51 $output .= "Number of records deleted = $result\n"; 52 } else { 53 $output = "Could not delete DB cache_filters entry for $algebra\nbecause it could not be found.\n"; 54 } 55 } 56 if ($action == 'TeXStage1') { 57 $output = algebra2tex($algebra); 58 } 59 if ($action == 'TexStage2') { 60 $output = algebra2tex($algebra); 61 $output = refineTeX($output); 62 } 63 if ($action == 'ShowImage'|| $action == 'SlashArguments') { 64 $output = algebra2tex($algebra); 65 $output = refineTeX($output); 66 if ($action == 'ShowImage') { 67 tex2image($output, $md5); 68 } else { 69 slasharguments($output, $md5); 70 } 71 } else { 72 outputText($output); 73 } 74 exit; 75 } 76 77 function algebra2tex($algebra) { 78 global $CFG; 79 $algebra = str_replace('<','<',$algebra); 80 $algebra = str_replace('>','>',$algebra); 81 $algebra = str_replace('<>','#',$algebra); 82 $algebra = str_replace('<=','%',$algebra); 83 $algebra = str_replace('>=','!',$algebra); 84 $algebra = preg_replace('/([=><%!#] *)-/',"\$1 zeroplace -",$algebra); 85 $algebra = str_replace('delta','zdelta',$algebra); 86 $algebra = str_replace('beta','bita',$algebra); 87 $algebra = str_replace('theta','thita',$algebra); 88 $algebra = str_replace('zeta','zita',$algebra); 89 $algebra = str_replace('eta','xeta',$algebra); 90 $algebra = str_replace('epsilon','zepslon',$algebra); 91 $algebra = str_replace('upsilon','zupslon',$algebra); 92 $algebra = preg_replace('!\r\n?!',' ',$algebra); 93 $algebra = escapeshellarg($algebra); 94 95 if ( (PHP_OS == "WINNT") || (PHP_OS == "WIN32") || (PHP_OS == "Windows") ) { 96 $cmd = "cd $CFG->dirroot\\filter\\algebra & algebra2tex.pl x/2"; 97 $test = `$cmd`; 98 if ($test != '\frac{x}{2}') { 99 echo "There is a problem with either Perl or the script algebra2tex.pl<br/>"; 100 $ecmd = $cmd . " 2>&1"; 101 echo `$ecmd` . "<br/>\n"; 102 echo "The shell command<br/>$cmd<br/>returned status = $status<br/>\n"; 103 $commandpath = "$CFG->dirroot\\filter\\algebra\\algebra2tex.pl"; 104 if (file_exists($commandpath)) { 105 echo "The file permissions of algebra2tex.pl are: " . decoct(fileperms($commandpath)) . "<br/>"; 106 } 107 die; 108 } 109 $cmd = "cd $CFG->dirroot\\filter\\algebra & algebra2tex.pl $algebra"; 110 } else { 111 $cmd = "cd $CFG->dirroot/filter/algebra; ./algebra2tex.pl x/2"; 112 $test = `$cmd`; 113 if ($test != '\frac{x}{2}') { 114 echo "There is a problem with either Perl or the script algebra2tex.pl<br/>"; 115 $ecmd = $cmd . " 2>&1"; 116 echo `$ecmd` . "<br/>\n"; 117 echo "The shell command<br/>$cmd<br/>returned status = $status<br/>\n"; 118 $commandpath = "$CFG->dirroot/filter/algebra/algebra2tex.pl"; 119 if (file_exists($commandpath)) { 120 echo "The file permissions of algebra2tex.pl are: " . decoct(fileperms($commandpath)) . "<br/>"; 121 } 122 die; 123 } 124 $cmd = "cd $CFG->dirroot/filter/algebra; ./algebra2tex.pl $algebra"; 125 } 126 $texexp = `$cmd`; 127 return $texexp; 128 } 129 130 function refineTeX($texexp) { 131 $texexp = str_replace('zeroplace','',$texexp); 132 $texexp = str_replace('#','\not= ',$texexp); 133 $texexp = str_replace('%','\leq ',$texexp); 134 $texexp = str_replace('!','\geq ',$texexp); 135 $texexp = str_replace('\left{','{',$texexp); 136 $texexp = str_replace('\right}','}',$texexp); 137 $texexp = str_replace('\fun',' ',$texexp); 138 $texexp = str_replace('infty','\infty',$texexp); 139 $texexp = str_replace('alpha','\alpha',$texexp); 140 $texexp = str_replace('gamma','\gamma',$texexp); 141 $texexp = str_replace('iota','\iota',$texexp); 142 $texexp = str_replace('kappa','\kappa',$texexp); 143 $texexp = str_replace('lambda','\lambda',$texexp); 144 $texexp = str_replace('mu','\mu',$texexp); 145 $texexp = str_replace('nu','\nu',$texexp); 146 $texexp = str_replace('xi','\xi',$texexp); 147 $texexp = str_replace('rho','\rho',$texexp); 148 $texexp = str_replace('sigma','\sigma',$texexp); 149 $texexp = str_replace('tau','\tau',$texexp); 150 $texexp = str_replace('phi','\phi',$texexp); 151 $texexp = str_replace('chi','\chi',$texexp); 152 $texexp = str_replace('psi','\psi',$texexp); 153 $texexp = str_replace('omega','\omega',$texexp); 154 $texexp = str_replace('zdelta','\delta',$texexp); 155 $texexp = str_replace('bita','\beta',$texexp); 156 $texexp = str_replace('thita','\theta',$texexp); 157 $texexp = str_replace('zita','\zeta',$texexp); 158 $texexp = str_replace('xeta','\eta',$texexp); 159 $texexp = str_replace('zepslon','\epsilon',$texexp); 160 $texexp = str_replace('zupslon','\upsilon',$texexp); 161 $texexp = str_replace('\mbox{logten}','\mbox{log}_{10}',$texexp); 162 $texexp = str_replace('\mbox{acos}','\mbox{cos}^{-1}',$texexp); 163 $texexp = str_replace('\mbox{asin}','\mbox{sin}^{-1}',$texexp); 164 $texexp = str_replace('\mbox{atan}','\mbox{tan}^{-1}',$texexp); 165 $texexp = str_replace('\mbox{asec}','\mbox{sec}^{-1}',$texexp); 166 $texexp = str_replace('\mbox{acsc}','\mbox{csc}^{-1}',$texexp); 167 $texexp = str_replace('\mbox{acot}','\mbox{cot}^{-1}',$texexp); 168 $texexp = str_replace('\mbox{acosh}','\mbox{cosh}^{-1}',$texexp); 169 $texexp = str_replace('\mbox{asinh}','\mbox{sinh}^{-1}',$texexp); 170 $texexp = str_replace('\mbox{atanh}','\mbox{tanh}^{-1}',$texexp); 171 $texexp = str_replace('\mbox{asech}','\mbox{sech}^{-1}',$texexp); 172 $texexp = str_replace('\mbox{acsch}','\mbox{csch}^{-1}',$texexp); 173 $texexp = str_replace('\mbox{acoth}','\mbox{coth}^{-1}',$texexp); 174 $texexp = preg_replace('/\\\sqrt{(.+?),(.+?)}/s','\sqrt['. "\$2]{\$1}",$texexp); 175 $texexp = preg_replace('/\\\mbox{abs}\\\left\((.+?)\\\right\)/s',"|\$1|",$texexp); 176 $texexp = preg_replace('/\\\log\\\left\((.+?),(.+?)\\\right\)/s','\log_{'. "\$2}\\left(\$1\\right)",$texexp); 177 $texexp = preg_replace('/(\\\cos|\\\sin|\\\tan|\\\sec|\\\csc|\\\cot)([h]*)\\\left\((.+?),(.+?)\\\right\)/s',"\$1\$2^{". "\$4}\\left(\$3\\right)",$texexp); 178 $texexp = preg_replace('/\\\int\\\left\((.+?),(.+?),(.+?)\\\right\)/s','\int_'. "{\$2}^{\$3}\$1 ",$texexp); 179 $texexp = preg_replace('/\\\int\\\left\((.+?d[a-z])\\\right\)/s','\int '. "\$1 ",$texexp); 180 $texexp = preg_replace('/\\\lim\\\left\((.+?),(.+?),(.+?)\\\right\)/s','\lim_'. "{\$2\\to \$3}\$1 ",$texexp); 181 return $texexp; 182 } 183 184 function outputText($texexp) { 185 header("Content-type: text/html; charset=utf-8"); 186 echo "<html><body><pre>\n"; 187 if ($texexp) { 188 $texexp = str_replace('<','<',$texexp); 189 $texexp = str_replace('>','>',$texexp); 190 $texexp = str_replace('"','"',$texexp); 191 echo "$texexp\n\n"; 192 } else { 193 echo "No text output available\n\n"; 194 } 195 echo "</pre></body></html>\n"; 196 } 197 198 function tex2image($texexp, $md5, $return=false) { 199 global $CFG; 200 201 if (!$texexp) { 202 echo 'No tex expresion specified'; 203 return; 204 } 205 206 $texexp = '\Large ' . $texexp; 207 $image = $md5 . ".gif"; 208 $filetype = 'image/gif'; 209 if (!file_exists("$CFG->dataroot/filter/algebra")) { 210 make_upload_directory("filter/algebra"); 211 } 212 $pathname = "$CFG->dataroot/filter/algebra/$image"; 213 if (file_exists($pathname)) { 214 unlink($pathname); 215 } 216 $commandpath = filter_tex_get_executable(true); 217 $cmd = filter_tex_get_cmd($pathname, $texexp); 218 system($cmd, $status); 219 220 if ($return) { 221 return $image; 222 } 223 if (file_exists($pathname)) { 224 send_file($pathname, $image); 225 226 } else { 227 $ecmd = "$cmd 2>&1"; 228 echo `$ecmd` . "<br />\n"; 229 echo "The shell command<br />$cmd<br />returned status = $status<br />\n"; 230 if ($status == 4) { 231 echo "Status corresponds to illegal instruction<br />\n"; 232 } else if ($status == 11) { 233 echo "Status corresponds to bus error<br />\n"; 234 } else if ($status == 22) { 235 echo "Status corresponds to abnormal termination<br />\n"; 236 } 237 if (file_exists($commandpath)) { 238 echo "File size of mimetex executable $commandpath is " . filesize($commandpath) . "<br />"; 239 echo "The file permissions are: " . decoct(fileperms($commandpath)) . "<br />"; 240 if (function_exists("md5_file")) { 241 echo "The md5 checksum of the file is " . md5_file($commandpath) . "<br />"; 242 } else { 243 $handle = fopen($commandpath,"rb"); 244 $contents = fread($handle,16384); 245 fclose($handle); 246 echo "The md5 checksum of the first 16384 bytes is " . md5($contents) . "<br />"; 247 } 248 } else { 249 echo "mimetex executable $commandpath not found!<br />"; 250 } 251 echo "Image not found!"; 252 } 253 } 254 255 function slasharguments($texexp, $md5) { 256 global $CFG; 257 $admin = $CFG->wwwroot.'/'.$CFG->admin.'/settings.php?section=http'; 258 $image = tex2image($texexp,$md5,true); 259 echo "<p>If the following image displays correctly, set your "; 260 echo "<a href=\"$admin\" target=\"_blank\">Administration->Server->HTTP</a> "; 261 echo "setting for slasharguments to file.php/1/pic.jpg: "; 262 echo "<img src=\"pix.php/$image\" align=\"absmiddle\"></p>\n"; 263 echo "<p>Otherwise set it to file.php?file=/1/pic.jpg "; 264 echo "It should display correctly as "; 265 echo "<img src=\"pix.php?file=$image\" align=\"absmiddle\"></p>\n"; 266 echo "<p>If neither equation image displays correctly, please seek "; 267 echo "further help at moodle.org at the "; 268 echo "<a href=\"http://moodle.org/mod/forum/view.php?id=752&loginguest=true\" target=\"_blank\">"; 269 echo "Mathematics Tools Forum</a></p>"; 270 } 271 272 ?> 273 274 <html> 275 <head><title>Algebra Filter Debugger</title></head> 276 <body> 277 <p>Please enter an algebraic expression <b>without</b> any surrounding @@ into 278 the text box below. (Click <a href="#help">here for help.</a>) 279 <form action="algebradebug.php" method="get" 280 target="inlineframe"> 281 <center> 282 <label for="algebra" class="accesshide"><?php print_string('algebraicexpression', 'filter_algebra'); ?></label> 283 <input type="text" id="algebra" name="algebra" size="50" 284 value="sin(z)/(x^2+y^2)" /> 285 </center> 286 <ol> 287 <li>First click on this button <button type="submit" name="action" value="ShowDB">Show DB Entry</button> 288 to see the cache_filters database entry for this expression.</li> 289 <li>If the database entry looks corrupt, click on this button to delete it: 290 <button type="submit" name="action" value="DeleteDB">Delete DB Entry</button></li> 291 <li>Now click on this button <button type="submit" name="action" value="TeXStage1">First Stage Tex Translation</button>. 292 A preliminary translation into TeX will appear in the box below.</li> 293 <li>Next click on this button <button type="submit" name="action" value="TexStage2">Second Stage Tex Translation</button>. 294 A more refined translation into TeX will appear in the box below.</li> 295 <li>Then click on this button <button type="submit" name="action" value="ShowImage">Show Image</button> 296 to show a graphic image of the algebraic expression.</li> 297 <li>Finally check your slash arguments setting 298 <button type="submit" name="action" value="SlashArguments">Check Slash Arguments</button></li> 299 </ol> 300 <input type="hidden" name="sesskey" value="<?php echo sesskey(); ?>" /> 301 </form> <br /> <br /> 302 <center> 303 <iframe name="inlineframe" align="middle" width="80%" height="200"> 304 <p>Something is wrong...</p> 305 </iframe> 306 </center> <br /> 307 <hr /> 308 <a name="help"> 309 <h2>Debugging Help</h2> 310 </a> 311 <p>First here is a brief overview on how the algebra filter works. It 312 takes an algebra expression and first translates it into TeX. It first 313 looks for the TeX translation in the Moodle database in the table cache_filters 314 in the field rawtext. If not found, it passes the algebraic expression to the 315 Perl script algebra2tex.pl, which also uses the Perl library AlgParser.pm. 316 It then saves the TeX translation in the database for subsequent uses and 317 passes the TeX to the mimetex executable to be converted to a gif image. 318 Here are a few common things that can go wrong and some suggestions on how 319 you might try to fix them.</p> 320 <ol> 321 <li>Something had gone wrong on a previous occasion when the filter tried to 322 translate this expression. Then the database entry for that expression contains 323 a bad TeX translation in the rawtext field (usually blank). You can fix this 324 by clicking on "Delete DB Entry"</li> 325 <li>The First Stage TeX Translation gives a "No text output available" 326 message. If your server is running Windows, this may be due to the fact that 327 you haven't installed Perl or didn't install it correctly. If your server is 328 running some version of Unix (e.g. Linux), then this may be due to your Perl 329 binary being installed in a nonstandard location. To fix this edit the first 330 line of the algebra2tex.pl script. Another possible problem which may affect 331 both Unix and Windows servers is that the web server doesn't have execute permission 332 on the algebra2tex.pl script. In that case change permissions accordingly</li> 333 <li>The Second Stage TeX Translation produces malformed TeX. This indicates 334 a bug in the algebra filter. Post the original algebraic expression and the 335 bad TeX translation in the <a href="http://moodle.org/mod/forum/view.php?id=752"> 336 Mathematics Tools</a> forum in the Using Moodle course on moodle.org.</li> 337 <li>The TeX to gif image conversion process does not work. If your server is 338 running Unix, a likely cause is that the mimetex binary you are using is 339 incompatible with your operating system. You can try compiling it from the 340 C sources downloaded from <a href="http://www.forkosh.com/mimetex.zip"> 341 http://www.forkosh.com/mimetex.zip</a>. Lastly check the execute permissions 342 on your mimetex binary, as outlined in item 2 above.</li> 343 </ol> 344 </body> 345 </html>
title
Description
Body
title
Description
Body
title
Description
Body
title
Body
