| [ Index ] |
PHP Cross Reference of moodle-2.8 |
[Summary view] [Print] [Text view]
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 define('NO_MOODLE_COOKIES', true); // Because it interferes with caching 7 8 require_once("../../config.php"); 9 10 if (!filter_is_enabled('algebra')) { 11 print_error('filternotenabled'); 12 } 13 14 require_once($CFG->libdir.'/filelib.php'); 15 require_once($CFG->dirroot.'/filter/tex/lib.php'); 16 17 require_login(); 18 require_capability('moodle/site:config', context_system::instance()); 19 20 $query = urldecode($_SERVER['QUERY_STRING']); 21 22 if ($query) { 23 $output = $query; 24 $splitpos = strpos($query,'&')-8; 25 $algebra = substr($query,8,$splitpos); 26 $md5 = md5($algebra); 27 if (strpos($query,'ShowDB') || strpos($query,'DeleteDB')) { 28 $texcache = $DB->get_record("cache_filters", array("filter"=>"algebra", "md5key"=>$md5)); 29 } 30 if (strpos($query,'ShowDB')) { 31 if ($texcache) { 32 $output = "DB cache_filters entry for $algebra\n"; 33 $output .= "id = $texcache->id\n"; 34 $output .= "filter = $texcache->filter\n"; 35 $output .= "version = $texcache->version\n"; 36 $output .= "md5key = $texcache->md5key\n"; 37 $output .= "rawtext = $texcache->rawtext\n"; 38 $output .= "timemodified = $texcache->timemodified\n"; 39 } else { 40 $output = "DB cache_filters entry for $algebra not found\n"; 41 } 42 } 43 if (strpos($query,'DeleteDB')) { 44 if ($texcache) { 45 $output = "Deleting DB cache_filters entry for $algebra\n"; 46 $result = $DB->delete_records("cache_filters", array("id"=>$texcache->id)); 47 if ($result) { 48 $result = 1; 49 } else { 50 $result = 0; 51 } 52 $output .= "Number of records deleted = $result\n"; 53 } else { 54 $output = "Could not delete DB cache_filters entry for $algebra\nbecause it could not be found.\n"; 55 } 56 } 57 if (strpos($query,'TeXStage1')) { 58 $output = algebra2tex($algebra); 59 } 60 if (strpos($query,'TeXStage2')) { 61 $output = algebra2tex($algebra); 62 $output = refineTeX($output); 63 } 64 if (strpos($query,'ShowImage')||strpos($query,'SlashArguments')) { 65 $output = algebra2tex($algebra); 66 $output = refineTeX($output); 67 if (strpos($query,'ShowImage')) { 68 tex2image($output, $md5); 69 } else { 70 slasharguments($output, $md5); 71 } 72 } else { 73 outputText($output); 74 } 75 exit; 76 } 77 78 function algebra2tex($algebra) { 79 global $CFG; 80 $algebra = str_replace('<','<',$algebra); 81 $algebra = str_replace('>','>',$algebra); 82 $algebra = str_replace('<>','#',$algebra); 83 $algebra = str_replace('<=','%',$algebra); 84 $algebra = str_replace('>=','!',$algebra); 85 $algebra = preg_replace('/([=><%!#] *)-/',"\$1 zeroplace -",$algebra); 86 $algebra = str_replace('delta','zdelta',$algebra); 87 $algebra = str_replace('beta','bita',$algebra); 88 $algebra = str_replace('theta','thita',$algebra); 89 $algebra = str_replace('zeta','zita',$algebra); 90 $algebra = str_replace('eta','xeta',$algebra); 91 $algebra = str_replace('epsilon','zepslon',$algebra); 92 $algebra = str_replace('upsilon','zupslon',$algebra); 93 $algebra = preg_replace('!\r\n?!',' ',$algebra); 94 $algebra = escapeshellarg($algebra); 95 96 if ( (PHP_OS == "WINNT") || (PHP_OS == "WIN32") || (PHP_OS == "Windows") ) { 97 $cmd = "cd $CFG->dirroot\\filter\\algebra & algebra2tex.pl x/2"; 98 $test = `$cmd`; 99 if ($test != '\frac{x}{2}') { 100 echo "There is a problem with either Perl or the script algebra2tex.pl<br/>"; 101 $ecmd = $cmd . " 2>&1"; 102 echo `$ecmd` . "<br/>\n"; 103 echo "The shell command<br/>$cmd<br/>returned status = $status<br/>\n"; 104 $commandpath = "$CFG->dirroot\\filter\\algebra\\algebra2tex.pl"; 105 if (file_exists($commandpath)) { 106 echo "The file permissions of algebra2tex.pl are: " . decoct(fileperms($commandpath)) . "<br/>"; 107 } 108 die; 109 } 110 $cmd = "cd $CFG->dirroot\\filter\\algebra & algebra2tex.pl $algebra"; 111 } else { 112 $cmd = "cd $CFG->dirroot/filter/algebra; ./algebra2tex.pl x/2"; 113 $test = `$cmd`; 114 if ($test != '\frac{x}{2}') { 115 echo "There is a problem with either Perl or the script algebra2tex.pl<br/>"; 116 $ecmd = $cmd . " 2>&1"; 117 echo `$ecmd` . "<br/>\n"; 118 echo "The shell command<br/>$cmd<br/>returned status = $status<br/>\n"; 119 $commandpath = "$CFG->dirroot/filter/algebra/algebra2tex.pl"; 120 if (file_exists($commandpath)) { 121 echo "The file permissions of algebra2tex.pl are: " . decoct(fileperms($commandpath)) . "<br/>"; 122 } 123 die; 124 } 125 $cmd = "cd $CFG->dirroot/filter/algebra; ./algebra2tex.pl $algebra"; 126 } 127 $texexp = `$cmd`; 128 return $texexp; 129 } 130 131 function refineTeX($texexp) { 132 $texexp = str_replace('zeroplace','',$texexp); 133 $texexp = str_replace('#','\not= ',$texexp); 134 $texexp = str_replace('%','\leq ',$texexp); 135 $texexp = str_replace('!','\geq ',$texexp); 136 $texexp = str_replace('\left{','{',$texexp); 137 $texexp = str_replace('\right}','}',$texexp); 138 $texexp = str_replace('\fun',' ',$texexp); 139 $texexp = str_replace('infty','\infty',$texexp); 140 $texexp = str_replace('alpha','\alpha',$texexp); 141 $texexp = str_replace('gamma','\gamma',$texexp); 142 $texexp = str_replace('iota','\iota',$texexp); 143 $texexp = str_replace('kappa','\kappa',$texexp); 144 $texexp = str_replace('lambda','\lambda',$texexp); 145 $texexp = str_replace('mu','\mu',$texexp); 146 $texexp = str_replace('nu','\nu',$texexp); 147 $texexp = str_replace('xi','\xi',$texexp); 148 $texexp = str_replace('rho','\rho',$texexp); 149 $texexp = str_replace('sigma','\sigma',$texexp); 150 $texexp = str_replace('tau','\tau',$texexp); 151 $texexp = str_replace('phi','\phi',$texexp); 152 $texexp = str_replace('chi','\chi',$texexp); 153 $texexp = str_replace('psi','\psi',$texexp); 154 $texexp = str_replace('omega','\omega',$texexp); 155 $texexp = str_replace('zdelta','\delta',$texexp); 156 $texexp = str_replace('bita','\beta',$texexp); 157 $texexp = str_replace('thita','\theta',$texexp); 158 $texexp = str_replace('zita','\zeta',$texexp); 159 $texexp = str_replace('xeta','\eta',$texexp); 160 $texexp = str_replace('zepslon','\epsilon',$texexp); 161 $texexp = str_replace('zupslon','\upsilon',$texexp); 162 $texexp = str_replace('\mbox{logten}','\mbox{log}_{10}',$texexp); 163 $texexp = str_replace('\mbox{acos}','\mbox{cos}^{-1}',$texexp); 164 $texexp = str_replace('\mbox{asin}','\mbox{sin}^{-1}',$texexp); 165 $texexp = str_replace('\mbox{atan}','\mbox{tan}^{-1}',$texexp); 166 $texexp = str_replace('\mbox{asec}','\mbox{sec}^{-1}',$texexp); 167 $texexp = str_replace('\mbox{acsc}','\mbox{csc}^{-1}',$texexp); 168 $texexp = str_replace('\mbox{acot}','\mbox{cot}^{-1}',$texexp); 169 $texexp = str_replace('\mbox{acosh}','\mbox{cosh}^{-1}',$texexp); 170 $texexp = str_replace('\mbox{asinh}','\mbox{sinh}^{-1}',$texexp); 171 $texexp = str_replace('\mbox{atanh}','\mbox{tanh}^{-1}',$texexp); 172 $texexp = str_replace('\mbox{asech}','\mbox{sech}^{-1}',$texexp); 173 $texexp = str_replace('\mbox{acsch}','\mbox{csch}^{-1}',$texexp); 174 $texexp = str_replace('\mbox{acoth}','\mbox{coth}^{-1}',$texexp); 175 $texexp = preg_replace('/\\\sqrt{(.+?),(.+?)}/s','\sqrt['. "\$2]{\$1}",$texexp); 176 $texexp = preg_replace('/\\\mbox{abs}\\\left\((.+?)\\\right\)/s',"|\$1|",$texexp); 177 $texexp = preg_replace('/\\\log\\\left\((.+?),(.+?)\\\right\)/s','\log_{'. "\$2}\\left(\$1\\right)",$texexp); 178 $texexp = preg_replace('/(\\\cos|\\\sin|\\\tan|\\\sec|\\\csc|\\\cot)([h]*)\\\left\((.+?),(.+?)\\\right\)/s',"\$1\$2^{". "\$4}\\left(\$3\\right)",$texexp); 179 $texexp = preg_replace('/\\\int\\\left\((.+?),(.+?),(.+?)\\\right\)/s','\int_'. "{\$2}^{\$3}\$1 ",$texexp); 180 $texexp = preg_replace('/\\\int\\\left\((.+?d[a-z])\\\right\)/s','\int '. "\$1 ",$texexp); 181 $texexp = preg_replace('/\\\lim\\\left\((.+?),(.+?),(.+?)\\\right\)/s','\lim_'. "{\$2\\to \$3}\$1 ",$texexp); 182 return $texexp; 183 } 184 185 function outputText($texexp) { 186 header("Content-type: text/html; charset=utf-8"); 187 echo "<html><body><pre>\n"; 188 if ($texexp) { 189 $texexp = str_replace('<','<',$texexp); 190 $texexp = str_replace('>','>',$texexp); 191 $texexp = str_replace('"','"',$texexp); 192 echo "$texexp\n\n"; 193 } else { 194 echo "No text output available\n\n"; 195 } 196 echo "</pre></body></html>\n"; 197 } 198 199 function tex2image($texexp, $md5, $return=false) { 200 global $CFG; 201 202 if (!$texexp) { 203 echo 'No tex expresion specified'; 204 return; 205 } 206 207 $texexp = '\Large ' . $texexp; 208 $image = $md5 . ".gif"; 209 $filetype = 'image/gif'; 210 if (!file_exists("$CFG->dataroot/filter/algebra")) { 211 make_upload_directory("filter/algebra"); 212 } 213 $pathname = "$CFG->dataroot/filter/algebra/$image"; 214 if (file_exists($pathname)) { 215 unlink($pathname); 216 } 217 $commandpath = filter_tex_get_executable(true); 218 $cmd = filter_tex_get_cmd($pathname, $texexp); 219 system($cmd, $status); 220 221 if ($return) { 222 return $image; 223 } 224 if (file_exists($pathname)) { 225 send_file($pathname, $image); 226 227 } else { 228 $ecmd = "$cmd 2>&1"; 229 echo `$ecmd` . "<br />\n"; 230 echo "The shell command<br />$cmd<br />returned status = $status<br />\n"; 231 if ($status == 4) { 232 echo "Status corresponds to illegal instruction<br />\n"; 233 } else if ($status == 11) { 234 echo "Status corresponds to bus error<br />\n"; 235 } else if ($status == 22) { 236 echo "Status corresponds to abnormal termination<br />\n"; 237 } 238 if (file_exists($commandpath)) { 239 echo "File size of mimetex executable $commandpath is " . filesize($commandpath) . "<br />"; 240 echo "The file permissions are: " . decoct(fileperms($commandpath)) . "<br />"; 241 if (function_exists("md5_file")) { 242 echo "The md5 checksum of the file is " . md5_file($commandpath) . "<br />"; 243 } else { 244 $handle = fopen($commandpath,"rb"); 245 $contents = fread($handle,16384); 246 fclose($handle); 247 echo "The md5 checksum of the first 16384 bytes is " . md5($contents) . "<br />"; 248 } 249 } else { 250 echo "mimetex executable $commandpath not found!<br />"; 251 } 252 echo "Image not found!"; 253 } 254 } 255 256 function slasharguments($texexp, $md5) { 257 global $CFG; 258 $admin = $CFG->wwwroot.'/'.$CFG->admin.'/settings.php?section=http'; 259 $image = tex2image($texexp,$md5,true); 260 echo "<p>If the following image displays correctly, set your "; 261 echo "<a href=\"$admin\" target=\"_blank\">Administration->Server->HTTP</a> "; 262 echo "setting for slasharguments to file.php/1/pic.jpg: "; 263 echo "<img src=\"pix.php/$image\" align=\"absmiddle\"></p>\n"; 264 echo "<p>Otherwise set it to file.php?file=/1/pic.jpg "; 265 echo "It should display correctly as "; 266 echo "<img src=\"pix.php?file=$image\" align=\"absmiddle\"></p>\n"; 267 echo "<p>If neither equation image displays correctly, please seek "; 268 echo "further help at moodle.org at the "; 269 echo "<a href=\"http://moodle.org/mod/forum/view.php?id=752&loginguest=true\" target=\"_blank\">"; 270 echo "Mathematics Tools Forum</a></p>"; 271 } 272 273 ?> 274 275 <html> 276 <head><title>Algebra Filter Debugger</title></head> 277 <body> 278 <p>Please enter an algebraic expression <b>without</b> any surrounding @@ into 279 the text box below. (Click <a href="#help">here for help.</a>) 280 <form action="algebradebug.php" method="get" 281 target="inlineframe"> 282 <center> 283 <label for="algebra" class="accesshide"><?php print_string('algebraicexpression', 'filter_algebra'); ?></label> 284 <input type="text" id="algebra" name="algebra" size="50" 285 value="sin(z)/(x^2+y^2)" /> 286 </center> 287 <ol> 288 <li>First click on this button <input type="submit" name="ShowDB" value="Show DB Entry" /> 289 to see the cache_filters database entry for this expression.</li> 290 <li>If the database entry looks corrupt, click on this button to delete it: 291 <input type="submit" name="DeleteDB" value="Delete DB Entry" /></li> 292 <li>Now click on this button <input type="submit" name="TeXStage1" value="First Stage Tex Translation" />. 293 A preliminary translation into TeX will appear in the box below.</li> 294 <li>Next click on this button <input type="submit" name="TeXStage2" value="Second Stage Tex Translation" />. 295 A more refined translation into TeX will appear in the box below.</li> 296 <li>Then click on this button <input type="submit" name="ShowImage" value="Show Image" /> 297 to show a graphic image of the algebraic expression.</li> 298 <li>Finally check your slash arguments setting 299 <input type="submit" name="SlashArguments" value="Check Slash Arguments" /></li> 300 </ol> 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>, or looking for an appropriate 342 binary at <a href="http://moodle.org/download/mimetex/"> 343 http://moodle.org/download/mimetex/</a>. You may then also need to 344 edit your moodle/filter/algebra/pix.php file to add 345 <br /><?php echo "case "" . PHP_OS . "":" ;?><br ?> to the list of operating systems 346 in the switch (PHP_OS) statement. Windows users may have a problem properly 347 unzipping mimetex.exe. Make sure that mimetex.exe is is <b>PRECISELY</b> 348 433152 bytes in size. If not, download fresh copy from 349 <a href="http://moodle.org/download/mimetex/windows/mimetex.exe"> 350 http://moodle.org/download/mimetex/windows/mimetex.exe</a>. Lastly check 351 the execute permissions on your mimetex binary, as outlined in item 2 above.</li> 352 </ol> 353 </body> 354 </html>
title
Description
Body
title
Description
Body
title
Description
Body
title
Body
| Generated: Fri Nov 28 20:29:05 2014 | Cross-referenced by PHPXref 0.7.1 |