source: moodle/trunk/fuentes/filter/tex/texdebug.php @ 1331

Last change on this file since 1331 was 1331, checked in by jrpelegrina, 3 years ago

Updated to moodle 3.0.3

File size: 16.1 KB
RevLine 
[136]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 fiedorow@math.ohio-state.edu
25 *             Originally based on code provided by Bruno Vernier bruno@vsbeducation.ca
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(), $USER->id); /// Required cap to run this. MDL-18552
[1331]44    if ($action || $texexp) {
45        require_sesskey();
46    }
[136]47
48    $output = '';
49
50    // look up in cache if required
51    if ($action=='ShowDB' or $action=='DeleteDB') {
52        $md5 = md5($texexp);
53        $texcache = $DB->get_record("cache_filters", array("filter"=>"tex", "md5key"=>$md5));
54    }
55
56    // Action: Show DB Entry
57    if ($action=='ShowDB') {
58        if ($texcache) {
59            $output = "DB cache_filters entry for $texexp\n";
60            $output .= "id = $texcache->id\n";
61            $output .= "filter = $texcache->filter\n";
62            $output .= "version = $texcache->version\n";
63            $output .= "md5key = $texcache->md5key\n";
64            $output .= "rawtext = $texcache->rawtext\n";
65            $output .= "timemodified = $texcache->timemodified\n";
66        } else {
67            $output = "DB cache_filters entry for $texexp not found\n";
68        }
69    }
70
71    // Action: Delete DB Entry
72    if ($action=='DeleteDB') {
73        if ($texcache) {
74            $output = "Deleting DB cache_filters entry for $texexp\n";
75            $result =  $DB->delete_records("cache_filters", array("id"=>$texcache->id));
76            if ($result) {
77                $result = 1;
78            } else {
79                $result = 0;
80            }
81            $output .= "Number of records deleted = $result\n";
82        } else {
83            $output = "Could not delete DB cache_filters entry for $texexp\nbecause it could not be found.\n";
84        }
85    }
86
87    // Action: Show Image
88    if ($action=='ShowImageMimetex') {
89        tex2image($texexp);
90    }
91
92    // Action: Check Slasharguments
93    if ($action=='SlashArguments') {
94        slasharguments($texexp);
[1331]95        exit;
[136]96    }
97
98    // Action: Show Tex command line output
99    if ($action=='ShowImageTex') {
100        TexOutput($texexp, true);
101        exit;
102    }
103
104    // Action: Show Tex command line output
105    if ($action=='ShowOutputTex') {
106        if (debugging()) {
107            TexOutput($texexp);
108        } else {
109            echo "Can not output detailed information due to security concerns, please turn on debug mode first.";
110        }
111        exit;
112    }
113
114    if (!empty($action)) {
115        outputText($output);
116    }
117
118    // nothing more to do if there was any action
119    if (!empty($action)) {
120        exit;
121    }
122
123
124    function outputText($texexp) {
125        header("Content-type: text/html; charset=utf-8");
126        echo "<html><body><pre>\n";
127        if ($texexp) {
128            echo s($texexp)."\n\n";
129        } else {
130            echo "No text output available\n\n";
131        }
132        echo "</pre></body></html>\n";
133    }
134
135    function tex2image($texexp, $return=false) {
136        global $CFG;
137
138        if (!$texexp) {
139            echo 'No tex expresion specified';
140            return;
141        }
142
143        $image  = md5($texexp) . ".gif";
144        $filetype = 'image/gif';
145        if (!file_exists("$CFG->dataroot/filter/tex")) {
146            make_upload_directory("filter/tex");
147        }
148        $pathname = "$CFG->dataroot/filter/tex/$image";
149        if (file_exists($pathname)) {
150            unlink($pathname);
151        }
152
153        $texexp = '\Large '.$texexp;
154        $commandpath = filter_tex_get_executable(true);
155        $cmd = filter_tex_get_cmd($pathname, $texexp);
156        system($cmd, $status);
157
158        if ($return) {
159          return $image;
160        }
161
162        if (file_exists($pathname)) {
163            send_file($pathname, $image);
164
165        } else if (debugging()) {
166            $ecmd = "$cmd 2>&1";
167            echo `$ecmd` . "<br />\n";
168            echo "The shell command<br />$cmd<br />returned status = $status<br />\n";
169            if ($status == 4) {
170                echo "Status corresponds to illegal instruction<br />\n";
171            } else if ($status == 11) {
172                echo "Status corresponds to bus error<br />\n";
173            } else if ($status == 22) {
174                echo "Status corresponds to abnormal termination<br />\n";
175            }
176            if (file_exists($commandpath)) {
177                echo "File size of mimetex executable  $commandpath is " . filesize($commandpath) . "<br />";
178                echo "The file permissions are: " . decoct(fileperms($commandpath)) . "<br />";
179                if (function_exists("md5_file")) {
180                    echo "The md5 checksum of the file is " . md5_file($commandpath) . "<br />";
181                } else {
182                    $handle = fopen($commandpath,"rb");
183                    $contents = fread($handle,16384);
184                    fclose($handle);
185                    echo "The md5 checksum of the first 16384 bytes is " . md5($contents) . "<br />";
186                }
187            } else {
188                echo "mimetex executable $commandpath not found!<br />";
189            }
190            echo "Image not found!";
191        } else {
192            echo "Can not output detailed information due to security concerns, please turn on debug mode first.";
193        }
194    }
195
196
197    // test Tex/Ghostscript output - command execution only
198    function TexOutput($expression, $graphic=false) {
199        global $CFG;
200        $output = '';
201
202        $latex = new latex();
203
204        // first check if it is likely to work at all
205        $output .= "<h3>Checking executables</h3>\n";
206        $executablesexist = true;
207        $pathlatex = trim(get_config('filter_tex', 'pathlatex'), " '\"");
208        if (is_file($pathlatex)) {
209            $output .= "latex executable ($pathlatex) is readable<br />\n";
210        } else {
211            $executablesexist = false;
212            $output .= "<b>Error:</b> latex executable ($pathlatex) is not readable<br />\n";
213        }
214        $pathdvips = trim(get_config('filter_tex', 'pathdvips'), " '\"");
215        if (is_file($pathdvips)) {
216            $output .= "dvips executable ($pathdvips) is readable<br />\n";
217        } else {
218            $executablesexist = false;
219            $output .= "<b>Error:</b> dvips executable ($pathdvips) is not readable<br />\n";
220        }
221        $pathconvert = trim(get_config('filter_tex', 'pathconvert'), " '\"");
222        if (is_file($pathconvert)) {
223            $output .= "convert executable ($pathconvert) is readable<br />\n";
224        } else {
225            $executablesexist = false;
226            $output .= "<b>Error:</b> convert executable ($pathconvert) is not readable<br />\n";
227        }
228        $pathdvisvgm = trim(get_config('filter_tex', 'pathdvisvgm'), " '\"");
229        if (is_file($pathdvisvgm)) {
230            $output .= "dvisvgm executable ($pathdvisvgm) is readable<br />\n";
231        } else {
232            $executablesexist = false;
233            $output .= "<b>Error:</b> dvisvgm executable ($pathdvisvgm) is not readable<br />\n";
234        }
235
236        // knowing that it might work..
237        $md5 = md5($expression);
238        $output .= "<p>base filename for expression is '$md5'</p>\n";
239
240        // temporary paths
241        $tex = "$latex->temp_dir/$md5.tex";
242        $dvi = "$latex->temp_dir/$md5.dvi";
243        $ps = "$latex->temp_dir/$md5.ps";
244        $convertformat = get_config('filter_tex', 'convertformat');
245        $img = "$latex->temp_dir/$md5.{$convertformat}";
246
247        // put the expression as a file into the temp area
248        $expression = html_entity_decode($expression);
249        $output .= "<p>Processing TeX expression:</p><pre>$expression</pre>\n";
250        $doc = $latex->construct_latex_document($expression);
251        $fh = fopen($tex, 'w');
252        fputs($fh, $doc);
253        fclose($fh);
254
255        // cd to temp dir
256        chdir($latex->temp_dir);
257
258        // step 1: latex command
259        $pathlatex = escapeshellarg($pathlatex);
260        $cmd = "$pathlatex --interaction=nonstopmode --halt-on-error $tex";
261        $output .= execute($cmd);
262
263        // step 2: dvips command
264        $pathdvips = escapeshellarg($pathdvips);
265        $cmd = "$pathdvips -E $dvi -o $ps";
266        $output .= execute($cmd);
267
268        // Step 3: Set convert or dvisvgm command.
269        if ($convertformat == 'svg') {
270            $pathdvisvgm = escapeshellarg($pathdvisvgm);
271            $cmd = "$pathdvisvgm -E $ps -o $img";
272        } else {
273            $pathconvert = escapeshellarg($pathconvert);
274            $cmd = "$pathconvert -density 240 -trim $ps $img ";
275        }
276        $output .= execute($cmd);
277
278        if (!$graphic) {
279            echo $output;
280        } else if (file_exists($img)) {
281            send_file($img, "$md5.{$convertformat}");
282        } else {
283            echo "Error creating image, see command execution output for more details.";
284        }
285    }
286
287    function execute($cmd) {
288        exec($cmd, $result, $code);
289        $output = "<pre>$ $cmd\n";
290        $lines = implode("\n", $result);
291        $output .= "OUTPUT: $lines\n";
292        $output .= "RETURN CODE: $code\n</pre>\n";
293        return $output;
294    }
295
296    function slasharguments($texexp) {
297        global $CFG;
298        $admin = $CFG->wwwroot.'/'.$CFG->admin.'/settings.php?section=http';
299        $image = tex2image($texexp,true);
300        echo "<p>If the following image displays correctly, set your ";
301        echo "<a href=\"$admin\" target=\"_blank\">Administration->Server->HTTP</a> ";
302        echo "setting for slasharguments to file.php/1/pic.jpg: ";
303        echo "<img src=\"$CFG->wwwroot/filter/tex/pix.php/$image\" align=\"absmiddle\"></p>\n";
304        echo "<p>Otherwise set it to file.php?file=/1/pic.jpg ";
305        echo "It should display correctly as ";
306        echo "<img src=\"$CFG->wwwroot/filter/tex/pix.php?file=$image\" align=\"absmiddle\"></p>\n";
307        echo "<p>If neither equation image displays correctly, please seek ";
308        echo "further help at moodle.org at the ";
309        echo "<a href=\"http://moodle.org/mod/forum/view.php?id=752&loginguest=true\" target=\"_blank\">";
310        echo "Mathematics Tools Forum</a></p>";
311    }
312
313?>
314
315<html>
316<head><title>TeX Filter Debugger</title></head>
317<body>
318  <p>Please enter an algebraic expression <b>without</b> any surrounding $$ into
319       the text box below. (Click <a href="#help">here for help.</a>)
320          <form action="texdebug.php" method="get"
321           target="inlineframe">
322            <center>
323             <input type="text" name="tex" size="50"
324                    value="f(x)=\int_{-\infty}^x~e^{-t^2}dt" />
325            </center>
326           <p>The following tests are available:</p>
327           <ol>
328           <li><input type="radio" name="action" value="ShowDB" id="ShowDB" />
329               <label for="ShowDB">See the cache_filters database entry for this expression (if any).</label></li>
330           <li><input type="radio" name="action" value="DeleteDB" id="DeleteDB" />
331               <label for="DeleteDB">Delete the cache_filters database entry for this expression (if any).</label></li>
332           <li><input type="radio" name="action" value="ShowImageMimetex" id="ShowImageMimetex"  checked="checked" />
333               <label for="ShowImageMimetex">Show a graphic image of the algebraic expression rendered with mimetex.</label></li>
334           <li><input type="radio" name="action" value="ShowImageTex" id="ShowImageTex" />
335               <label for="ShowImageTex">Show a graphic image of the algebraic expression rendered with Tex/Ghostscript.</label></li>
336           <li><input type="radio" name="action" value="ShowOutputTex" id="ShowOutputTex" />
337               <label for="ShowOutputTex">Show command execution output from the algebraic expression rendered with Tex/Ghostscript.</label></li>
338           <li><input type="radio" name="action" value="SlashArguments" id="SlashArguments" />
339               <label for="SlashArguments">Check slasharguments setting.</label></li>
340           </ol>
341           <input type="submit" value="Do it!" />
[1331]342           <input type="hidden" name="sesskey" value="<?php echo sesskey(); ?>" />
[136]343          </form> <br /> <br />
344       <center>
345          <iframe name="inlineframe" align="middle" width="80%" height="200">
346          &lt;p&gt;Something is wrong...&lt;/p&gt;
347          </iframe>
348       </center> <br />
349<hr />
350<a name="help">
351<h2>Debugging Help</h2>
352</a>
353<p>First a brief overview of how the TeX filter works. The TeX filter first
354searches the database cache_filters table to see if this TeX expression had been
355processed before. If not, it adds a DB entry for that expression.  It then
356replaces the TeX expression by an &lt;img src=&quot;.../filter/tex/pix.php...&quot;&gt;
357tag.  The filter/tex/pix.php script then searches the database to find an
358appropriate gif/png/svg image file for that expression and to create one if it doesn't exist.
359It will then use either the LaTex/Ghostscript renderer (using external executables
360on your system) or the bundled Mimetex executable. The full Latex/Ghostscript
361renderer produces better results and is tried first.
362Here are a few common things that can go wrong and some suggestions on how
363you might try to fix them.</p>
364<ol>
365<li>Something had gone wrong on a previous occasion when the filter tried to
366process this expression. Then the database entry for that expression contains
367a bad TeX expression in the rawtext field (usually blank). You can fix this
368by clicking on &quot;Delete DB Entry&quot;</li>
369<li>The TeX to gif/png/svg image conversion process does not work.
370If paths are specified in the filter configuation screen for the three
371executables these will be tried first. Note that they still must be correctly
372installed and have the correct permissions. In particular make sure that you
373have all the packages installed (e.g., on Debian/Ubuntu you need to install
374the 'tetex-extra' package). Running the 'show command execution' test should
375give a big clue.
376If this fails or is not available, the Mimetex executable is tried. If this
377fails a likely cause is that the mimetex binary you are using is
378incompatible with your operating system. You can try compiling it from the
379C sources downloaded from <a href="http://www.forkosh.com/mimetex.zip">
380http://www.forkosh.com/mimetex.zip</a>, or looking for an appropriate
381binary at <a href="http://moodle.org/download/mimetex/">
382http://moodle.org/download/mimetex/</a>. You may then also need to
383edit your moodle/filter/tex/pix.php file to add
384<br /><?php echo "case &quot;" . PHP_OS . "&quot;:" ;?><br ?> to the list of operating systems
385in the switch (PHP_OS) statement. Windows users may have a problem properly
386unzipping mimetex.exe. Make sure that mimetex.exe is is <b>PRECISELY</b>
387433152 bytes in size. If not, download a fresh copy from
388<a href="http://moodle.org/download/mimetex/windows/mimetex.exe">
389http://moodle.org/download/mimetex/windows/mimetex.exe</a>.
390Another possible problem which may affect
391both Unix and Windows servers is that the web server doesn't have execute permission
392on the mimetex binary. In that case change permissions accordingly</li>
393</ol>
394</body>
395</html>
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