moodle/filter/tex/lib.php
stronk7 f6a5c4b0a7 MDL-18893 TeX filter - fine tune "def" commands + add some more commands to blacklist (from Kopete).
Thanks to Mauno Korpelainen and Steve Mayer. Merged from 19_STABLE
2009-04-20 21:25:45 +00:00

89 lines
3.3 KiB
PHP

<?php //$Id$
function tex_filter_get_executable($debug=false) {
global $CFG;
$error_message1 = "Your system is not configured to run mimeTeX. You need to download the appropriate<br />"
."executable for you ".PHP_OS." platform from <a href=\"http://moodle.org/download/mimetex/\">"
."http://moodle.org/download/mimetex/</a>, or obtain the C source<br /> "
."from <a href=\"http://www.forkosh.com/mimetex.zip\">"
."http://www.forkosh.com/mimetex.zip</a>, compile it and "
."put the executable into your<br /> moodle/filter/tex/ directory.";
$error_message2 = "Custom mimetex is not executable!<br /><br />";
if ((PHP_OS == "WINNT") || (PHP_OS == "WIN32") || (PHP_OS == "Windows")) {
return "$CFG->dirroot/filter/tex/mimetex.exe";
}
$custom_commandpath = "$CFG->dirroot/filter/tex/mimetex";
if (file_exists($custom_commandpath)) {
if (is_executable($custom_commandpath)) {
return $custom_commandpath;
} else {
print_error('mimetexnotexecutable', 'error');
}
}
switch (PHP_OS) {
case "Linux": return "$CFG->dirroot/filter/tex/mimetex.linux";
case "Darwin": return "$CFG->dirroot/filter/tex/mimetex.darwin";
case "FreeBSD": return "$CFG->dirroot/filter/tex/mimetex.freebsd";
}
print_error('mimetexisnotexist', 'error');
}
function tex_sanitize_formula($texexp) {
/// Check $texexp against blacklist (whitelisting could be more complete but also harder to maintain)
$tex_blacklist = array(
'include','command','loop','repeat','open','toks','output',
'input','catcode','name','^^',
'\def','\edef','\gdef','\xdef',
'\every','\errhelp','\errorstopmode','\scrollmode','\nonstopmode',
'\batchmode','\read','\write','csname','\newhelp','\uppercase',
'\lowercase','\relax','\aftergroup',
'\afterassignment','\expandafter','\noexpand','\special',
'\let', '\futurelet','\else','\fi','\chardef','\makeatletter','\afterground',
'\noexpand','\line','\mathcode','\item','\section','\mbox','\declarerobustcommand'
);
return str_ireplace($tex_blacklist, 'forbiddenkeyword', $texexp);
}
function tex_filter_get_cmd($pathname, $texexp) {
$texexp = tex_sanitize_formula($texexp);
$texexp = escapeshellarg($texexp);
$executable = tex_filter_get_executable(false);
if ((PHP_OS == "WINNT") || (PHP_OS == "WIN32") || (PHP_OS == "Windows")) {
$executable = str_replace(' ', '^ ', $executable);
return "$executable ++ -e \"$pathname\" -- $texexp";
} else {
return "\"$executable\" -e \"$pathname\" -- $texexp";
}
}
/**
* Purge all caches when settings changed.
*/
function filter_tex_updatedcallback($name) {
global $CFG, $DB;
reset_text_filters_cache();
if (file_exists("$CFG->dataroot/filter/tex")) {
remove_dir("$CFG->dataroot/filter/tex");
}
if (file_exists("$CFG->dataroot/filter/algebra")) {
remove_dir("$CFG->dataroot/filter/algebra");
}
if (file_exists("$CFG->dataroot/temp/latex")) {
remove_dir("$CFG->dataroot/temp/latex");
}
$DB->delete_records('cache_filters', array('filter'=>'tex'));
$DB->delete_records('cache_filters', array('filter'=>'algebra'));
}
?>