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PHP Cross Reference of Moodle 1.9.3 [Build 15-Oct-2008] |
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1 <?PHP // $Id: texdebug.php,v 1.20.2.2 2007/12/25 11:41:46 skodak Exp $ 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/tex', $filters) === FALSE) { 15 error ('Filter not enabled!'); 16 } 17 } 18 19 require_once($CFG->libdir.'/filelib.php'); 20 require_once($CFG->dirroot.'/filter/tex/lib.php'); 21 require_once($CFG->dirroot.'/filter/tex/latex.php'); 22 23 $action = optional_param('action', '', PARAM_ALPHA); 24 $texexp = optional_param('tex', '', PARAM_RAW); 25 26 $query = urldecode($_SERVER['QUERY_STRING']); 27 error_reporting(E_ALL); 28 $output = ''; 29 30 // look up in cache if required 31 if ($action=='ShowDB' or $action=='DeleteDB') { 32 $md5 = md5($texexp); 33 $texcache = get_record("cache_filters","filter","tex", "md5key", $md5); 34 } 35 36 // Action: Show DB Entry 37 if ($action=='ShowDB') { 38 if ($texcache) { 39 $output = "DB cache_filters entry for $texexp\n"; 40 $output .= "id = $texcache->id\n"; 41 $output .= "filter = $texcache->filter\n"; 42 $output .= "version = $texcache->version\n"; 43 $output .= "md5key = $texcache->md5key\n"; 44 $output .= "rawtext = $texcache->rawtext\n"; 45 $output .= "timemodified = $texcache->timemodified\n"; 46 } else { 47 $output = "DB cache_filters entry for $texexp not found\n"; 48 } 49 } 50 51 // Action: Delete DB Entry 52 if ($action=='DeleteDB') { 53 if ($texcache) { 54 $output = "Deleting DB cache_filters entry for $texexp\n"; 55 $result = delete_records("cache_filters","id",$texcache->id); 56 if ($result) { 57 $result = 1; 58 } else { 59 $result = 0; 60 } 61 $output .= "Number of records deleted = $result\n"; 62 } else { 63 $output = "Could not delete DB cache_filters entry for $texexp\nbecause it could not be found.\n"; 64 } 65 } 66 67 // Action: Show Image 68 if ($action=='ShowImageMimetex') { 69 tex2image($texexp); 70 } 71 72 // Action: Check Slasharguments 73 if ($action=='SlashArguments') { 74 slasharguments($texexp); 75 } 76 77 // Action: Show Tex command line output 78 if ($action=='ShowImageTex') { 79 TexOutput($texexp, true); 80 exit; 81 } 82 83 // Action: Show Tex command line output 84 if ($action=='ShowOutputTex') { 85 if (debugging()) { 86 TexOutput($texexp); 87 } else { 88 echo "Can not output detailed information due to security concerns, please turn on debug mode first."; 89 } 90 exit; 91 } 92 93 if (!empty($action)) { 94 outputText($output); 95 } 96 97 // nothing more to do if there was any action 98 if (!empty($action)) { 99 exit; 100 } 101 102 103 function outputText($texexp) { 104 header("Content-type: text/html"); 105 echo "<html><body><pre>\n"; 106 if ($texexp) { 107 $texexp = str_replace('<', '<', $texexp); 108 $texexp = str_replace('>', '>', $texexp); 109 $texexp = str_replace('"', '"', $texexp); 110 echo "$texexp\n\n"; 111 } else { 112 echo "No text output available\n\n"; 113 } 114 echo "</pre></body></html>\n"; 115 } 116 117 function tex2image($texexp, $return=false) { 118 global $CFG; 119 120 if (!$texexp) { 121 echo 'No tex expresion specified'; 122 return; 123 } 124 125 $image = md5($texexp) . ".gif"; 126 $filetype = 'image/gif'; 127 if (!file_exists("$CFG->dataroot/filter/tex")) { 128 make_upload_directory("filter/tex"); 129 } 130 $pathname = "$CFG->dataroot/filter/tex/$image"; 131 if (file_exists($pathname)) { 132 unlink($pathname); 133 } 134 135 $texexp = '\Large '.$texexp; 136 $commandpath = tex_filter_get_executable(true); 137 $cmd = tex_filter_get_cmd($pathname, $texexp); 138 system($cmd, $status); 139 140 if ($return) { 141 return $image; 142 } 143 144 if (file_exists($pathname)) { 145 send_file($pathname, $image); 146 147 } else if (debugging()) { 148 $ecmd = "$cmd 2>&1"; 149 echo `$ecmd` . "<br />\n"; 150 echo "The shell command<br />$cmd<br />returned status = $status<br />\n"; 151 if ($status == 4) { 152 echo "Status corresponds to illegal instruction<br />\n"; 153 } else if ($status == 11) { 154 echo "Status corresponds to bus error<br />\n"; 155 } else if ($status == 22) { 156 echo "Status corresponds to abnormal termination<br />\n"; 157 } 158 if (file_exists($commandpath)) { 159 echo "File size of mimetex executable $commandpath is " . filesize($commandpath) . "<br />"; 160 echo "The file permissions are: " . decoct(fileperms($commandpath)) . "<br />"; 161 if (function_exists("md5_file")) { 162 echo "The md5 checksum of the file is " . md5_file($commandpath) . "<br />"; 163 } else { 164 $handle = fopen($commandpath,"rb"); 165 $contents = fread($handle,16384); 166 fclose($handle); 167 echo "The md5 checksum of the first 16384 bytes is " . md5($contents) . "<br />"; 168 } 169 } else { 170 echo "mimetex executable $commandpath not found!<br />"; 171 } 172 echo "Image not found!"; 173 } else { 174 echo "Can not output detailed information due to security concerns, please turn on debug mode first."; 175 } 176 } 177 178 179 // test Tex/Ghostscript output - command execution only 180 function TexOutput($expression, $graphic=false) { 181 global $CFG; 182 $output = ''; 183 184 $latex = new latex(); 185 186 // first check if it is likely to work at all 187 $output .= "<h3>Checking executables</h3>\n"; 188 $executables_exist = true; 189 if (is_file($CFG->filter_tex_pathlatex)) { 190 $output .= "latex executable ($CFG->filter_tex_pathlatex) is readable<br />\n"; 191 } 192 else { 193 $executables_exist = false; 194 $output .= "<b>Error:</b> latex executable ($CFG->filter_tex_pathlatex) is not readable<br />\n"; 195 } 196 if (is_file($CFG->filter_tex_pathdvips)) { 197 $output .= "dvips executable ($CFG->filter_tex_pathdvips) is readable<br />\n"; 198 } 199 else { 200 $executables_exist = false; 201 $output .= "<b>Error:</b> dvips executable ($CFG->filter_tex_pathdvips) is not readable<br />\n"; 202 } 203 if (is_file($CFG->filter_tex_pathconvert)) { 204 $output .= "convert executable ($CFG->filter_tex_pathconvert) is readable<br />\n"; 205 } 206 else { 207 $executables_exist = false; 208 $output .= "<b>Error:</b> convert executable ($CFG->filter_tex_pathconvert) is not readable<br />\n"; 209 } 210 211 // knowing that it might work.. 212 $md5 = md5($expression); 213 $output .= "<p>base filename for expression is '$md5'</p>\n"; 214 215 // temporary paths 216 $tex = "$latex->temp_dir/$md5.tex"; 217 $dvi = "$latex->temp_dir/$md5.dvi"; 218 $ps = "$latex->temp_dir/$md5.ps"; 219 $gif = "$latex->temp_dir/$md5.gif"; 220 221 // put the expression as a file into the temp area 222 $expression = stripslashes($expression); 223 $expression = html_entity_decode($expression); 224 $output .= "<p>Processing TeX expression:</p><pre>$expression</pre>\n"; 225 $doc = $latex->construct_latex_document($expression); 226 $fh = fopen($tex, 'w'); 227 fputs($fh, $doc); 228 fclose($fh); 229 230 // cd to temp dir 231 chdir($latex->temp_dir); 232 233 // step 1: latex command 234 $cmd = "$CFG->filter_tex_pathlatex --interaction=nonstopmode $tex"; 235 $output .= execute($cmd); 236 237 // step 2: dvips command 238 $cmd = "$CFG->filter_tex_pathdvips -E $dvi -o $ps"; 239 $output .= execute($cmd); 240 241 // step 3: convert command 242 $cmd = "$CFG->filter_tex_pathconvert -density 240 -trim $ps $gif "; 243 $output .= execute($cmd); 244 245 if (!$graphic) { 246 echo($output); 247 } else { 248 send_file($gif, "$md5.gif"); 249 } 250 } 251 252 function execute($cmd) { 253 exec($cmd, $result, $code); 254 $output = "<pre>$ $cmd\n"; 255 $lines = implode("\n", $result); 256 $output .= "OUTPUT: $lines\n"; 257 $output .= "RETURN CODE: $code\n</pre>\n"; 258 return $output; 259 } 260 261 function slasharguments($texexp) { 262 global $CFG; 263 $admin = $CFG->wwwroot.'/'.$CFG->admin.'/settings.php?section=http'; 264 $image = tex2image($texexp,true); 265 echo "<p>If the following image displays correctly, set your "; 266 echo "<a href=\"$admin\" target=\"_blank\">Administration->Server->HTTP</a> "; 267 echo "setting for slasharguments to file.php/1/pic.jpg: "; 268 echo "<img src=\"$CFG->wwwroot/filter/tex/pix.php/$image\" align=\"absmiddle\"></p>\n"; 269 echo "<p>Otherwise set it to file.php?file=/1/pic.jpg "; 270 echo "It should display correctly as "; 271 echo "<img src=\"$CFG->wwwroot/filter/tex/pix.php?file=$image\" align=\"absmiddle\"></p>\n"; 272 echo "<p>If neither equation image displays correctly, please seek "; 273 echo "further help at moodle.org at the "; 274 echo "<a href=\"http://moodle.org/mod/forum/view.php?id=752&loginguest=true\" target=\"_blank\">"; 275 echo "Mathematics Tools Forum</a></p>"; 276 } 277 278 ?> 279 280 <html> 281 <head><title>TeX Filter Debugger</title></head> 282 <body> 283 <p>Please enter an algebraic expression <b>without</b> any surrounding $$ into 284 the text box below. (Click <a href="#help">here for help.</a>) 285 <form action="texdebug.php" method="get" 286 target="inlineframe"> 287 <center> 288 <input type="text" name="tex" size="50" 289 value="f(x)=\Bigint_{-\infty}^x~e^{-t^2}dt" /> 290 </center> 291 <p>The following tests are available:</p> 292 <ol> 293 <li><input type="radio" name="action" value="ShowDB" id="ShowDB" /> 294 <label for="ShowDB">See the cache_filters database entry for this expression (if any).</label></li> 295 <li><input type="radio" name="DeleteDB" value="DeleteDB" id="DeleteDB" /> 296 <label for="DeleteDB">Delete the cache_filters database entry for this expression (if any).</label></li> 297 <li><input type="radio" name="action" value="ShowImageMimetex" id="ShowImageMimetex checked="checked" /> 298 <label for="ShowImageMimetex">Show a graphic image of the algebraic expression rendered with mimetex.</label></li> 299 <li><input type="radio" name="action" value="ShowImageTex" id="ShowImageTex" /> 300 <label for="ShowImageTex">Show a graphic image of the algebraic expression rendered with Tex/Ghostscript.</label></li> 301 <li><input type="radio" name="action" value="ShowOutputTex" id="ShowOutputTex" /> 302 <label for="ShowOutputTex">Show command execution output from the algebraic expression rendered with Tex/Ghostscript.</label></li> 303 <li><input type="radio" name="action" value="SlashArguments" id="SlashArguments" /> 304 <label for="SlashArguments">Check slasharguments setting.</label></li> 305 </ol> 306 <input type="submit" value="Do it!" /> 307 </form> <br /> <br /> 308 <center> 309 <iframe name="inlineframe" align="middle" width="80%" height="200"> 310 <p>Something is wrong...</p> 311 </iframe> 312 </center> <br /> 313 <hr /> 314 <a name="help"> 315 <h2>Debugging Help</h2> 316 </a> 317 <p>First a brief overview of how the TeX filter works. The TeX filter first 318 searches the database cache_filters table to see if this TeX expression had been 319 processed before. If not, it adds a DB entry for that expression. It then 320 replaces the TeX expression by an <img src=".../filter/tex/pix.php..."> 321 tag. The filter/tex/pix.php script then searches the database to find an 322 appropriate gif image file for that expression and to create one if it doesn't exist. 323 It will then use either the LaTex/Ghostscript renderer (using external executables 324 on your system) or the bundled Mimetex executable. The full Latex/Ghostscript 325 renderer produces better results and is tried first. 326 Here are a few common things that can go wrong and some suggestions on how 327 you might try to fix them.</p> 328 <ol> 329 <li>Something had gone wrong on a previous occasion when the filter tried to 330 process this expression. Then the database entry for that expression contains 331 a bad TeX expression in the rawtext field (usually blank). You can fix this 332 by clicking on "Delete DB Entry"</li> 333 <li>The TeX to gif image conversion process does not work. 334 If paths are specified in the filter configuation screen for the three 335 executables these will be tried first. Note that they still must be correctly 336 installed and have the correct permissions. In particular make sure that you 337 have all the packages installed (e.g., on Debian/Ubuntu you need to install 338 the 'tetex-extra' package). Running the 'show command execution' test should 339 give a big clue. 340 If this fails or is not available, the Mimetex executable is tried. If this 341 fails a likely cause is that the mimetex binary you are using is 342 incompatible with your operating system. You can try compiling it from the 343 C sources downloaded from <a href="http://www.forkosh.com/mimetex.zip"> 344 http://www.forkosh.com/mimetex.zip</a>, or looking for an appropriate 345 binary at <a href="http://moodle.org/download/mimetex/"> 346 http://moodle.org/download/mimetex/</a>. You may then also need to 347 edit your moodle/filter/tex/pix.php file to add 348 <br /><?PHP echo "case "" . PHP_OS . "":" ;?><br ?> to the list of operating systems 349 in the switch (PHP_OS) statement. Windows users may have a problem properly 350 unzipping mimetex.exe. Make sure that mimetex.exe is is <b>PRECISELY</b> 351 433152 bytes in size. If not, download a fresh copy from 352 <a href="http://moodle.org/download/mimetex/windows/mimetex.exe"> 353 http://moodle.org/download/mimetex/windows/mimetex.exe</a>. 354 Another possible problem which may affect 355 both Unix and Windows servers is that the web server doesn't have execute permission 356 on the mimetex binary. In that case change permissions accordingly</li> 357 </ol> 358 </body> 359 </html>
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