thepurpleblob
406 lines
17 KiB
PHP
406 lines
17 KiB
PHP
<?PHP // $Id$
|
|
// This function fetches math. images from the data directory
|
|
// If not, it obtains the corresponding TeX expression from the cache_tex db table
|
|
// and uses mimeTeX to create the image file
|
|
|
|
$nomoodlecookie = true; // Because it interferes with caching
|
|
|
|
require_once("../../config.php");
|
|
require( 'latex.php' );
|
|
|
|
if (empty($CFG->textfilters)) {
|
|
error ('Filter not enabled!');
|
|
} else {
|
|
$filters = explode(',', $CFG->textfilters);
|
|
if (array_search('filter/tex', $filters) === FALSE) {
|
|
error ('Filter not enabled!');
|
|
}
|
|
}
|
|
|
|
$CFG->texfilterdir = "filter/tex";
|
|
$CFG->teximagedir = "filter/tex";
|
|
|
|
$param = null;
|
|
$param->action = optional_param( 'action','',PARAM_ALPHA );
|
|
$param->tex = optional_param( 'tex','' );
|
|
|
|
$query = urldecode($_SERVER['QUERY_STRING']);
|
|
error_reporting(E_ALL);
|
|
$output = '';
|
|
|
|
// look up in cache if required
|
|
if ($param->action=='ShowDB' or $param->action=='DeleteDB') {
|
|
$md5 = md5($param->tex);
|
|
$texcache = get_record("cache_filters","filter","tex", "md5key", $md5);
|
|
}
|
|
|
|
// Action: Show DB Entry
|
|
if ($param->action=='ShowDB') {
|
|
if ($texcache) {
|
|
$output = "DB cache_filters entry for $param->tex\n";
|
|
$output .= "id = $texcache->id\n";
|
|
$output .= "filter = $texcache->filter\n";
|
|
$output .= "version = $texcache->version\n";
|
|
$output .= "md5key = $texcache->md5key\n";
|
|
$output .= "rawtext = $texcache->rawtext\n";
|
|
$output .= "timemodified = $texcache->timemodified\n";
|
|
} else {
|
|
$output = "DB cache_filters entry for $param->tex not found\n";
|
|
}
|
|
}
|
|
|
|
// Action: Delete DB Entry
|
|
if ($param->action=='DeleteDB') {
|
|
if ($texcache) {
|
|
$output = "Deleting DB cache_filters entry for $param->tex\n";
|
|
$result = delete_records("cache_filters","id",$texcache->id);
|
|
if ($result) {
|
|
$result = 1;
|
|
} else {
|
|
$result = 0;
|
|
}
|
|
$output .= "Number of records deleted = $result\n";
|
|
} else {
|
|
$output = "Could not delete DB cache_filters entry for $param->tex\nbecause it could not be found.\n";
|
|
}
|
|
}
|
|
|
|
// Action: Show Image
|
|
if ($param->action=='ShowImageMimetex') {
|
|
tex2image($param->tex);
|
|
}
|
|
|
|
// Action: Check Slasharguments
|
|
if ($param->action=='SlashArguments') {
|
|
slasharguments($param->tex);
|
|
}
|
|
|
|
// Action: Show Tex command line output
|
|
if ($param->action=='ShowImageTex') {
|
|
TexOutput($param->tex, true);
|
|
exit;
|
|
}
|
|
|
|
// Action: Show Tex command line output
|
|
if ($param->action=='ShowOutputTex') {
|
|
TexOutput($param->tex);
|
|
exit;
|
|
}
|
|
|
|
if (!empty($param->action)) {
|
|
outputText($output);
|
|
}
|
|
|
|
// nothing more to do if there was any action
|
|
if (!empty($param->action)) {
|
|
exit;
|
|
}
|
|
|
|
|
|
function outputText($texexp) {
|
|
header("Content-type: text/html");
|
|
echo "<html><body><pre>\n";
|
|
if ($texexp) {
|
|
$texexp = str_replace('<','<',$texexp);
|
|
$texexp = str_replace('>','>',$texexp);
|
|
$texexp = str_replace('"','"',$texexp);
|
|
echo "$texexp\n\n";
|
|
} else {
|
|
echo "No text output available\n\n";
|
|
}
|
|
echo "</pre></body></html>\n";
|
|
}
|
|
|
|
function tex2image($texexp, $return=false) {
|
|
global $CFG;
|
|
$error_message1 = "Your system is not configured to run mimeTeX. ";
|
|
$error_message1 .= "You need to download the appropriate<br /> executable ";
|
|
$error_message1 .= "from <a href=\"http://moodle.org/download/mimetex/\">";
|
|
$error_message1 .= "http://moodle.org/download/mimetex/</a>, or obtain the ";
|
|
$error_message1 .= "C source<br /> from <a href=\"http://www.forkosh.com/mimetex.zip\">";
|
|
$error_message1 .= "http://www.forkosh.com/mimetex.zip</a>, compile it and ";
|
|
$error_message1 .= "put the executable into your<br /> moodle/filter/tex/ directory. ";
|
|
$error_message1 .= "You also need to edit your moodle/filter/tex/pix.php file<br />";
|
|
$error_message1 .= ' by adding the line<br /><pre> case "' . PHP_OS . "\":\n";
|
|
$error_message1 .= " \$cmd = \"\\\\\"\$CFG->dirroot/\$CFG->texfilterdir/";
|
|
$error_message1 .= 'mimetex.' . strtolower(PHP_OS) . "\\\\\" -e \\\\\"\$pathname\\\\\" \". escapeshellarg(\$texexp);";
|
|
$error_message1 .= "</pre>You also need to add this to your texdebug.php file.";
|
|
|
|
if ($texexp) {
|
|
$texexp = '\Large ' . $texexp;
|
|
$lifetime = 86400;
|
|
$image = md5($texexp) . ".gif";
|
|
$filetype = 'image/gif';
|
|
if (!file_exists("$CFG->dataroot/$CFG->teximagedir")) {
|
|
make_upload_directory($CFG->teximagedir);
|
|
}
|
|
$pathname = "$CFG->dataroot/$CFG->teximagedir/$image";
|
|
if (file_exists($pathname)) {
|
|
unlink($pathname);
|
|
}
|
|
$commandpath = "";
|
|
$cmd = "";
|
|
$texexp = escapeshellarg($texexp);
|
|
switch (PHP_OS) {
|
|
case "Linux":
|
|
$commandpath="$CFG->dirroot/$CFG->texfilterdir/mimetex.linux";
|
|
$cmd = "\"$CFG->dirroot/$CFG->texfilterdir/mimetex.linux\" -e \"$pathname\" $texexp";
|
|
break;
|
|
case "WINNT":
|
|
case "WIN32":
|
|
case "Windows":
|
|
$commandpath="$CFG->dirroot/$CFG->texfilterdir/mimetex.exe";
|
|
$cmd = str_replace(' ','^ ',$commandpath);
|
|
$cmd .= " ++ -e \"$pathname\" $texexp";
|
|
break;
|
|
case "Darwin":
|
|
$commandpath="$CFG->dirroot/$CFG->texfilterdir/mimetex.darwin";
|
|
$cmd = "\"$CFG->dirroot/$CFG->texfilterdir/mimetex.darwin\" -e \"$pathname\" $texexp";
|
|
break;
|
|
}
|
|
if (!$cmd) {
|
|
if (is_executable("$CFG->dirroot/$CFG->texfilterdir/mimetex")) { /// Use the custom binary
|
|
$commandpath="$CFG->dirroot/$CFG->texfilterdir/mimetex";
|
|
$cmd = "$CFG->dirroot/$CFG->texfilterdir/mimetex -e $pathname $texexp";
|
|
} else {
|
|
error($error_message1);
|
|
}
|
|
}
|
|
system($cmd, $status);
|
|
}
|
|
if ($return) {
|
|
return $image;
|
|
}
|
|
if ($texexp && file_exists($pathname)) {
|
|
$lastmodified = filemtime($pathname);
|
|
header("Last-Modified: " . gmdate("D, d M Y H:i:s", $lastmodified) . " GMT");
|
|
header("Expires: " . gmdate("D, d M Y H:i:s", time() + $lifetime) . " GMT");
|
|
header("Cache-control: max_age = $lifetime"); // a day
|
|
header("Pragma: ");
|
|
header("Content-disposition: inline; filename=$image");
|
|
header("Content-length: ".filesize($pathname));
|
|
header("Content-type: $filetype");
|
|
readfile("$pathname");
|
|
} else {
|
|
$ecmd = "$cmd 2>&1";
|
|
echo `$ecmd` . "<br />\n";
|
|
echo "The shell command<br />$cmd<br />returned status = $status<br />\n";
|
|
if ($status == 4) {
|
|
echo "Status corresponds to illegal instruction<br />\n";
|
|
} else if ($status == 11) {
|
|
echo "Status corresponds to bus error<br />\n";
|
|
} else if ($status == 22) {
|
|
echo "Status corresponds to abnormal termination<br />\n";
|
|
}
|
|
if (file_exists($commandpath)) {
|
|
echo "File size of mimetex executable $commandpath is " . filesize($commandpath) . "<br />";
|
|
echo "The file permissions are: " . decoct(fileperms($commandpath)) . "<br />";
|
|
if (function_exists("md5_file")) {
|
|
echo "The md5 checksum of the file is " . md5_file($commandpath) . "<br />";
|
|
} else {
|
|
$handle = fopen($commandpath,"rb");
|
|
$contents = fread($handle,16384);
|
|
fclose($handle);
|
|
echo "The md5 checksum of the first 16384 bytes is " . md5($contents) . "<br />";
|
|
}
|
|
} else {
|
|
echo "mimetex executable $commandpath not found!<br />";
|
|
}
|
|
echo "Image not found!";
|
|
}
|
|
}
|
|
|
|
|
|
// test Tex/Ghostscript output - command execution only
|
|
function TexOutput( $expression, $graphic=false ) {
|
|
global $CFG;
|
|
$output = '';
|
|
|
|
$latex = new latex();
|
|
|
|
// first check if it is likely to work at all
|
|
$output .= "<h3>Checking executables</h3>\n";
|
|
$executables_exist = true;
|
|
if (is_file($CFG->filter_tex_pathlatex)) {
|
|
$output .= "latex executable ($CFG->filter_tex_pathlatex) is readable<br />\n";
|
|
}
|
|
else {
|
|
$executables_exist = false;
|
|
$output .= "<b>Error:</b> latex executable ($CFG->filter_tex_pathlatex) is not readable<br />\n";
|
|
}
|
|
if (is_file($CFG->filter_tex_pathdvips)) {
|
|
$output .= "dvips executable ($CFG->filter_tex_pathdvips) is readable<br />\n";
|
|
}
|
|
else {
|
|
$executables_exist = false;
|
|
$output .= "<b>Error:</b> dvips executable ($CFG->filter_tex_pathdvips) is not readable<br />\n";
|
|
}
|
|
if (is_file($CFG->filter_tex_pathconvert)) {
|
|
$output .= "convert executable ($CFG->filter_tex_pathconvert) is readable<br />\n";
|
|
}
|
|
else {
|
|
$executables_exist = false;
|
|
$output .= "<b>Error:</b> convert executable ($CFG->filter_tex_pathconvert) is not readable<br />\n";
|
|
}
|
|
|
|
// knowing that it might work..
|
|
$md5 = md5( $expression );
|
|
$output .= "<p>base filename for expression is '$md5'</p>\n";
|
|
|
|
// temporary paths
|
|
$tex = "$latex->temp_dir/$md5.tex";
|
|
$dvi = "$latex->temp_dir/$md5.dvi";
|
|
$ps = "$latex->temp_dir/$md5.ps";
|
|
$gif = "$latex->temp_dir/$md5.gif";
|
|
|
|
// put the expression as a file into the temp area
|
|
$expression = stripslashes( $expression );
|
|
$expression = html_entity_decode( $expression );
|
|
$output .= "<p>Processing TeX expression:</p><pre>$expression</pre>\n";
|
|
$doc = $latex->construct_latex_document( $expression );
|
|
$fh = fopen( $tex, 'w' );
|
|
fputs( $fh, $doc );
|
|
fclose( $fh );
|
|
|
|
// cd to temp dir
|
|
chdir( $latex->temp_dir );
|
|
|
|
// step 1: latex command
|
|
$cmd = "$CFG->filter_tex_pathlatex --interaction=nonstopmode $tex";
|
|
$output .= execute( $cmd );
|
|
|
|
// step 2: dvips command
|
|
$cmd = "$CFG->filter_tex_pathdvips -E $dvi -o $ps";
|
|
$output .= execute( $cmd );
|
|
|
|
// step 3: convert command
|
|
$cmd = "$CFG->filter_tex_pathconvert -density 240 -trim $ps $gif ";
|
|
$output .= execute( $cmd );
|
|
|
|
if (!$graphic) {
|
|
echo( $output );
|
|
} else {
|
|
$lastmodified = filemtime($gif);
|
|
$lifetime = 86400;
|
|
$filetype = 'image/gif';
|
|
$image = "$md5.gif";
|
|
header("Last-Modified: " . gmdate("D, d M Y H:i:s", $lastmodified) . " GMT");
|
|
header("Expires: " . gmdate("D, d M Y H:i:s", time() + $lifetime) . " GMT");
|
|
header("Cache-control: max_age = $lifetime"); // a day
|
|
header("Pragma: ");
|
|
header("Content-disposition: inline; filename=$image");
|
|
header("Content-length: ".filesize($gif));
|
|
header("Content-type: $filetype");
|
|
readfile("$gif");
|
|
}
|
|
}
|
|
|
|
function execute( $cmd ) {
|
|
exec( $cmd, $result, $code );
|
|
$output = "<pre>$ $cmd\n";
|
|
$lines = implode( "\n", $result );
|
|
$output .= "OUTPUT: $lines\n";
|
|
$output .= "RETURN CODE: $code\n</pre>\n";
|
|
return $output;
|
|
}
|
|
|
|
function slasharguments($texexp) {
|
|
global $CFG;
|
|
$admin = $CFG->wwwroot . '/' . $CFG->admin . '/config.php';
|
|
$image = tex2image($texexp,true);
|
|
echo "<p>If the following image displays correctly, set your ";
|
|
echo "<a href=\"$admin\" target=\"_blank\">Administration->Configuration->Variables</a> ";
|
|
echo "setting for slasharguments to file.php/1/pic.jpg: ";
|
|
echo "<img src=\"pix.php/$image\" align=\"absmiddle\"></p>\n";
|
|
echo "<p>Otherwise set it to file.php?file=/1/pic.jpg ";
|
|
echo "It should display correctly as ";
|
|
echo "<img src=\"pix.php?file=$image\" align=\"absmiddle\"></p>\n";
|
|
echo "<p>If neither equation image displays correctly, please seek ";
|
|
echo "further help at moodle.org at the ";
|
|
echo "<a href=\"http://moodle.org/mod/forum/view.php?id=752&username=guest\" target=\"_blank\">";
|
|
echo "Mathematics Tools Forum</a></p>";
|
|
}
|
|
|
|
?>
|
|
|
|
<html>
|
|
<head><title>TeX Filter Debugger</title></head>
|
|
<body>
|
|
<p>Please enter an algebraic expression <b>without</b> any surrounding $$ into
|
|
the text box below. (Click <a href="#help">here for help.</a>)
|
|
<form action="texdebug.php" method="get"
|
|
target="inlineframe">
|
|
<center>
|
|
<input type="text" name="tex" size="50"
|
|
value="f(x)=\Bigint_{-\infty}^x~e^{-t^2}dt" />
|
|
</center>
|
|
<p>The following tests are available:</p>
|
|
<ol>
|
|
<li><input type="radio" name="action" value="ShowDB" />
|
|
See the cache_filters database entry for this expression (if any).</li>
|
|
<li><input type="radio" name="DeleteDB" value="DeleteDB" />
|
|
Delete the cache_filters database entry for this expression (if any).</li>
|
|
<li><input type="radio" name="action" value="ShowImageMimetex" />
|
|
Show a graphic image of the algebraic expression rendered with mimetex.</li>
|
|
<li><input type="radio" name="action" value="ShowImageTex" />
|
|
Show a graphic image of the algebraic expression rendered with Tex/Ghostscript.</li>
|
|
<li><input type="radio" name="action" value="ShowOutputTex" />
|
|
Show command execution output from the algebraic expression rendered with Tex/Ghostscript.</li>
|
|
<li><input type="radio" name="action" value="SlashArguments" />
|
|
Check slasharguments setting.</li>
|
|
</ol>
|
|
<input type="submit" value="Do it!" />
|
|
</form> <br /> <br />
|
|
<center>
|
|
<iframe name="inlineframe" align="middle" width="80%" height="200">
|
|
<p>Something is wrong...</p>
|
|
</iframe>
|
|
</center> <br />
|
|
<hr />
|
|
<a name="help">
|
|
<h2>Debugging Help</h2>
|
|
</a>
|
|
<p>First a brief overview of how the TeX filter works. The TeX filter first
|
|
searches the database cache_filters table to see if this TeX expression had been
|
|
processed before. If not, it adds a DB entry for that expression. It then
|
|
replaces the TeX expression by an <img src=".../filter/tex/pix.php...">
|
|
tag. The filter/tex/pix.php script then searches the database to find an
|
|
appropriate gif image file for that expression and to create one if it doesn't exist.
|
|
It will then use either the LaTex/Ghostscript renderer (using external executables
|
|
on your system) or the bundled Mimetex executable. The full Latex/Ghostscript
|
|
renderer produces better results and is tried first.
|
|
Here are a few common things that can go wrong and some suggestions on how
|
|
you might try to fix them.</p>
|
|
<ol>
|
|
<li>Something had gone wrong on a previous occasion when the filter tried to
|
|
process this expression. Then the database entry for that expression contains
|
|
a bad TeX expression in the rawtext field (usually blank). You can fix this
|
|
by clicking on "Delete DB Entry"</li>
|
|
<li>The TeX to gif image conversion process does not work.
|
|
If paths are specified in the filter configuation screen for the three
|
|
executables these will be tried first. Note that they still must be correctly
|
|
installed and have the correct permissions. In particular make sure that you
|
|
have all the packages installed (e.g., on Debian/Ubuntu you need to install
|
|
the 'tetex-extra' package). Running the 'show command execution' test should
|
|
give a big clue.
|
|
If this fails or is not available, the Mimetex executable is tried. If this
|
|
fails a likely cause is that the mimetex binary you are using is
|
|
incompatible with your operating system. You can try compiling it from the
|
|
C sources downloaded from <a href="http://www.forkosh.com/mimetex.zip">
|
|
http://www.forkosh.com/mimetex.zip</a>, or looking for an appropriate
|
|
binary at <a href="http://moodle.org/download/mimetex/">
|
|
http://moodle.org/download/mimetex/</a>. You may then also need to
|
|
edit your moodle/filter/tex/pix.php file to add
|
|
<br /><?PHP echo "case "" . PHP_OS . "":" ;?><br ?> to the list of operating systems
|
|
in the switch (PHP_OS) statement. Windows users may have a problem properly
|
|
unzipping mimetex.exe. Make sure that mimetex.exe is is <b>PRECISELY</b>
|
|
433152 bytes in size. If not, download a fresh copy from
|
|
<a href="http://moodle.org/download/mimetex/windows/mimetex.exe">
|
|
http://moodle.org/download/mimetex/windows/mimetex.exe</a>.
|
|
Another possible problem which may affect
|
|
both Unix and Windows servers is that the web server doesn't have execute permission
|
|
on the mimetex binary. In that case change permissions accordingly</li>
|
|
</ol>
|
|
</body>
|
|
</html>
|