algbot.php

<?php

class algbot {
    private static $channels;

    function construct() {
        $this->channels = array( '#debug' => 1 );
        $this->event_eos();
    }

    function destruct() {
        $ircd = &ircd();
        $ircd->quit('AlgBot', 'Module Unloaded.');
    }
    
    function event_msg($target, $nick, $message) {
        if (isset($this->channels[strtolower($target)])) {
            $d = $message;
            $ircd = &ircd();
            $command = explode(' ', $d)[0];
            $message = join(' ', array_slice($message, 1));
                
            switch(strtolower($command)) {
                case '.math':
                    $pid = pcntl_fork();
                    if ($pid == 0) {
                        set_time_limit(6);
                        $e = new EvalMath;
                        $s = explode(';',$message);
                        foreach ($s as $c) {
                            if (strtolower($c) != 'print') {
                                $l = @$e->e($c);
                            } else {
                                $ircd->msg('AlgBot', $target, $l);
                            }
                        }
                        $ircd->msg('AlgBot', $target, $nick.': '.$l);
                        unset($l);
                        unset($s);
                        unset($c);
                        unset($e);
                        die();
                    }
                    break;
                case '.gcalc':
                    $pid = pcntl_fork();
                    if ($pid == 0) {
                        set_time_limit(6);
                        ini_set('user_agent','Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9b3pre) Gecko/2008011704 (Gentoo) Firefox/3.0b3pre');
                        //<img src=/images/calc_img.gif width=40 height=30 alt=""></td><td>&nbsp;</td><td nowrap dir=ltr><h2 class=r><font size=+1><b>
                        if (preg_match('|\<img src\=/.*\.gif .* alt\=""\>\</td\>\<td\>&nbsp;\</td\>\<td nowrap dir\=ltr\>\<h2 class\=r\>\<font size\=\+1\>\<b\>(.*)\</b\>\<\/h2\>\</td\>\</tr\>\<tr\>|',($debug = file_get_contents('http://www.google.com/search?q='.urlencode(str_replace('E',' * 10^',$message.'=')))),$m)){
                            $ircd->msg('AlgBot', $target, $nick.': '.html_entity_decode(strip_tags(str_replace(array('<sup>','&#215;'),array('^','*'),$m[1]))));
                        }
                        echo $debug."\n";
                        die();
                    }
                    break;
                case '.bcmath':
                    $pid = pcntl_fork();
                    if ($pid == 0) {
                        set_time_limit(6);
                        $descriptorspec = array(0=>array('pipe','r'),1=>array('pipe','w'),2=>array('file','/dev/null','a'));
                        $bc = proc_open('/usr/bin/bc -lq',$descriptorspec,$pipes,null,array('BC_LINE_LENGTH' => 512));
                        $pid = pcntl_fork();
                        if ($pid == 0) {
                            fclose($pipes[0]);
                            fclose($pipes[1]);
                            sleep(4);
                            if (is_resource($bc)) {
                                $tmp = proc_get_status($bc);
                                posix_kill($tmp['pid'],SIGTERM);
                            }
                            die();
                        } elseif ($pid > 0) {
                            fwrite($pipes[0],$message."\nquit\n");
                            fclose($pipes[0]);
                            stream_set_timeout($pipes[1],5);
                            $ircd->msg('AlgBot', $target, $nick.': '.str_replace(array("\n","\r"),'',fgets($pipes[1],512)));
                            fclose($pipes[1]);
                            proc_close($bc);
                            sleep(6);
                            die();
                        } else {
                            die();
                        }
                    } elseif ($pid > 0) {
                        /* Parent */
                    } else {
                        /* Whoops */
                    }
                    break;
                case '.gnuplot':
                    if (fnmatch('*output*',$message)) break;
                    $pid = pcntl_fork();
                    if ($pid == 0) {
                        set_time_limit(12);
                        $descriptorspec = array(0=>array('pipe','r'),1=>array('file','/dev/null','a'),2=>array('file','/dev/null','a'));
                        $gnuplot = proc_open('/usr/bin/gnuplot -',$descriptorspec,$pipes,null,array('BC_LINE_LENGTH' => 512));
                        $pid = pcntl_fork();
                        if ($pid == 0) {
                            fclose($pipes[0]);
                            sleep(10);
                            if (is_resource($gnuplot)) {
                                $tmp = proc_get_status($gnuplot);
                                posix_kill($tmp['pid'],SIGTERM);
                            }
                            die();
                        } elseif ($pid > 0) {
                            $tmp = tempnam('/tmp', 'gnuplot');
                            fwrite($pipes[0],"set term png\nset output \"".$tmp."\"\n".$message."\nexit\n");
                            fclose($pipes[0]);
                            proc_close($gnuplot);
                            $md5 = md5_file($tmp);
                            system('chmod a+r '.escapeshellarg($tmp));
                            system('scp '.escapeshellarg($tmp).' '.escapeshellarg('[email protected]:/home/cobi/algbot/'.$md5.'.png'));
                            unlink($tmp);
                            $ircd->msg('AlgBot', $target, $nick.': Your graph is available at http://euclid.cluenet.org/algbot/'.$md5.'.png'."\n");
                            sleep(12);
                            die();
                        } else {
                            die();
                        }
                    } elseif ($pid > 0) {
                        /* Parent */
                    } else {
                        /* Whoops */
                    }
                    break;
                case '.solve':
                    $message = 'solve('.$message.',x)';
                case '.giac':
                    $pid = pcntl_fork();
                    if ($pid == 0) {
                        set_time_limit(16);
                        $descriptorspec = array(0=>array('pipe','r'),1=>array('pipe','w'),2=>array('file','/dev/null','a'));
                        $giac = proc_open('/usr/local/bin/giac /proc/self/fd/0',$descriptorspec,$pipes);
                        $pid = pcntl_fork();
                        if ($pid == 0) {
                            fclose($pipes[0]);
                            fclose($pipes[1]);
                            sleep(13);
                            if (is_resource($giac)) {
                                $tmp = proc_get_status($giac);
                                posix_kill($tmp['pid'],SIGTERM);
                            }
                            die();
                        } elseif ($pid > 0) {
                            fwrite($pipes[0],$message."\n");
                            fclose($pipes[0]);
                            stream_set_timeout($pipes[1],15);
                            $ircd->msg('AlgBot', $target, $nick.': '.str_replace(array("\n","\r"),'',fgets($pipes[1],512))."\n");
                            fclose($pipes[1]);
                            proc_close($giac);
                            sleep(16);
                            die();
                        } else {
                            die();
                        }
                    } elseif ($pid > 0) {
                        /* Parent */
                    } else {
                        /* Whoops */
                    }
                    break;
                case '.help':
                case '.commands':
                    $pid = pcntl_fork();
                    if ($pid == 0) {
                        set_time_limit(60);
                        $ircd->notice($nick, 'Commands: (trigger = .)');
                        $ircd->notice($nick, 'Commands: (trigger = .)');
                        $ircd->notice($nick, '---');
                        $ircd->notice($nick, 'math - Simple math.  [sim] [func] [trig] [vars]');
                        $ircd->notice($nick, 'gcalc - Advanced math. [sim] [func] [trig] [unit] [da] [imag] [cmpx]');
                        $ircd->notice($nick, 'bcmath - High precision math. [sim] [func] [trig] [abit] [prog]');
                        $ircd->notice($nick, 'solve - Algebraically solve for x. [sim] [func] [trig] [vars] [imag] [cmpx] [alg] [ip]');
                        $ircd->notice($nick, 'giac - Algebra. [sim] [func] [trig] [vars] [imag] [cmpx] [prog] [alg] [ip]');
                        $ircd->notice($nick, '---');
                        $ircd->notice($nick, '[sim] = Simple math. [func] = Math functions. [trig] = Trigonometry functions. [vars] = Basic variable support. [imag] = Imaginary numbers. [cmpx] = Complex numbers. [unit] = Units support. [da] = Dimensional analysis.');
                        $ircd->notice($nick, '[abit] = Arbitrary precision. [prog] = Program flow control. [alg] = Algebra-related functions. [ip] = Infinate precision.');
                        die();
                    }
                    break;
            }
        }    
    }
    
    function event_invite ($from,$to,$chan) {
        if (strtolower($to) == 'algbot') {
            $this->channels[strtolower($chan)] = 1;
            $ircd = &ircd();
            $ircd->join('AlgBot',$chan);
        }
    }
    
    function event_kick ($from,$who,$to,$reason) {
        if (strtolower($who) == 'algbot') {
            unset($this->channels[strtolower($to)]);
        }
    }
    
    function event_eos() {
        global $mysql;
        $ircd = &ircd();
        
        $ircd->addnick($mysql->getsetting('server'), 'AlgBot', 'algbot', 'algbot.phpserv.cluenet.org', 'AlgBot');
        foreach ($this->channels as $y => $x) {
            $ircd->join('AlgBot', $y);
        }
    }
}

class EvalMath {
    var $suppress_errors = false;
    var $last_error = null;

    var $v = array('e'=>2.71,'pi'=>3.14); // variables (and constants)
    var $f = array(); // user-defined functions
    var $vb = array('e', 'pi'); // constants
    var $fb = array(  // built-in functions
        'sin','sinh','arcsin','asin','arcsinh','asinh',
        'cos','cosh','arccos','acos','arccosh','acosh',
        'tan','tanh','arctan','atan','arctanh','atanh',
        'sqrt','abs','ln','log');
    
    function EvalMath() {
        // make the variables a little more accurate
        $this->v['pi'] = pi();
        $this->v['e'] = exp(1);
    }
    
    function e($expr) {
        return $this->evaluate($expr);
    }
    
    function evaluate($expr) {
        $this->last_error = null;
        $expr = trim($expr);
        if (substr($expr, -1, 1) == ';') $expr = substr($expr, 0, strlen($expr)-1); // strip semicolons at the end
        //===============
        // is it a variable assignment?
        if (preg_match('/^\s*([a-z]\w*)\s*=\s*(.+)$/', $expr, $matches)) {
            if (in_array($matches[1], $this->vb)) { // make sure we're not assigning to a constant
                return $this->trigger("cannot assign to constant '$matches[1]'");
            }
            if (($tmp = $this->pfx($this->nfx($matches[2]))) === false) return false; // get the result and make sure it's good
            $this->v[$matches[1]] = $tmp; // if so, stick it in the variable array
            return $this->v[$matches[1]]; // and return the resulting value
        //===============
        // is it a function assignment?
        } elseif (preg_match('/^\s*([a-z]\w*)\s*\(\s*([a-z]\w*(?:\s*,\s*[a-z]\w*)*)\s*\)\s*=\s*(.+)$/', $expr, $matches)) {
            $fnn = $matches[1]; // get the function name
            if (in_array($matches[1], $this->fb)) { // make sure it isn't built in
                return $this->trigger("cannot redefine built-in function '$matches[1]()'");
            }
            $args = explode(",", preg_replace("/\s+/", "", $matches[2])); // get the arguments
            if (($stack = $this->nfx($matches[3])) === false) return false; // see if it can be converted to postfix
            for ($i = 0; $i<count($stack); $i++) { // freeze the state of the non-argument variables
                $token = $stack[$i];
                if (preg_match('/^[a-z]\w*$/', $token) and !in_array($token, $args)) {
                    if (array_key_exists($token, $this->v)) {
                        $stack[$i] = $this->v[$token];
                    } else {
                        return $this->trigger("undefined variable '$token' in function definition");
                    }
                }
            }
            $this->f[$fnn] = array('args'=>$args, 'func'=>$stack);
            return true;
        //===============
        } else {
            return $this->pfx($this->nfx($expr)); // straight up evaluation, woo
        }
    }
    
    function vars() {
        $output = $this->v;
        unset($output['pi']);
        unset($output['e']);
        return $output;
    }
    
    function funcs() {
        $output = array();
        foreach ($this->f as $fnn=>$dat)
            $output[] = $fnn . '(' . implode(',', $dat['args']) . ')';
        return $output;
    }

    //===================== HERE BE INTERNAL METHODS ====================\\

    // Convert infix to postfix notation
    function nfx($expr) {
    
        $index = 0;
        $stack = new EvalMathStack;
        $output = array(); // postfix form of expression, to be passed to pfx()
        $expr = trim(strtolower($expr));
        
        $ops   = array('+', '-', '*', '/', '^', '_');
        $ops_r = array('+'=>0,'-'=>0,'*'=>0,'/'=>0,'^'=>1); // right-associative operator?  
        $ops_p = array('+'=>0,'-'=>0,'*'=>1,'/'=>1,'_'=>1,'^'=>2); // operator precedence
        
        $expecting_op = false; // we use this in syntax-checking the expression
                               // and determining when a - is a negation
    
        if (preg_match("/[^\w\s+*^\/()\.,-]/", $expr, $matches)) { // make sure the characters are all good
            return $this->trigger("illegal character '{$matches[0]}'");
        }
    
        while(1) { // 1 Infinite Loop ;)
            $op = substr($expr, $index, 1); // get the first character at the current index
            // find out if we're currently at the beginning of a number/variable/function/parenthesis/operand
            $ex = preg_match('/^([a-z]\w*\(?|\d+(?:\.\d*)?|\.\d+|\()/', substr($expr, $index), $match);
            //===============
            if ($op == '-' and !$expecting_op) { // is it a negation instead of a minus?
                $stack->push('_'); // put a negation on the stack
                $index++;
            } elseif ($op == '_') { // we have to explicitly deny this, because it's legal on the stack 
                return $this->trigger("illegal character '_'"); // but not in the input expression
            //===============
            } elseif ((in_array($op, $ops) or $ex) and $expecting_op) { // are we putting an operator on the stack?
                if ($ex) { // are we expecting an operator but have a number/variable/function/opening parethesis?
                    $op = '*'; $index--; // it's an implicit multiplication
                }
                // heart of the algorithm:
                while($stack->count > 0 and ($o2 = $stack->last()) and in_array($o2, $ops) and ($ops_r[$op] ? $ops_p[$op] < $ops_p[$o2] : $ops_p[$op] <= $ops_p[$o2])) {
                    $output[] = $stack->pop(); // pop stuff off the stack into the output
                }
                // many thanks: http://en.wikipedia.org/wiki/Reverse_Polish_notation#The_algorithm_in_detail
                $stack->push($op); // finally put OUR operator onto the stack
                $index++;
                $expecting_op = false;
            //===============
            } elseif ($op == ')' and $expecting_op) { // ready to close a parenthesis?
                while (($o2 = $stack->pop()) != '(') { // pop off the stack back to the last (
                    if (is_null($o2)) return $this->trigger("unexpected ')'");
                    else $output[] = $o2;
                }
                if (preg_match("/^([a-z]\w*)\($/", $stack->last(2), $matches)) { // did we just close a function?
                    $fnn = $matches[1]; // get the function name
                    $arg_count = $stack->pop(); // see how many arguments there were (cleverly stored on the stack, thank you)
                    $output[] = $stack->pop(); // pop the function and push onto the output
                    if (in_array($fnn, $this->fb)) { // check the argument count
                        if($arg_count > 1)
                            return $this->trigger("too many arguments ($arg_count given, 1 expected)");
                    } elseif (array_key_exists($fnn, $this->f)) {
                        if ($arg_count != count($this->f[$fnn]['args']))
                            return $this->trigger("wrong number of arguments ($arg_count given, " . count($this->f[$fnn]['args']) . " expected)");
                    } else { // did we somehow push a non-function on the stack? this should never happen
                        return $this->trigger("internal error");
                    }
                }
                $index++;
            //===============
            } elseif ($op == ',' and $expecting_op) { // did we just finish a function argument?
                while (($o2 = $stack->pop()) != '(') { 
                    if (is_null($o2)) return $this->trigger("unexpected ','"); // oops, never had a (
                    else $output[] = $o2; // pop the argument expression stuff and push onto the output
                }
                // make sure there was a function
                if (!preg_match("/^([a-z]\w*)\($/", $stack->last(2), $matches))
                    return $this->trigger("unexpected ','");
                $stack->push($stack->pop()+1); // increment the argument count
                $stack->push('('); // put the ( back on, we'll need to pop back to it again
                $index++;
                $expecting_op = false;
            //===============
            } elseif ($op == '(' and !$expecting_op) {
                $stack->push('('); // that was easy
                $index++;
                $allow_neg = true;
            //===============
            } elseif ($ex and !$expecting_op) { // do we now have a function/variable/number?
                $expecting_op = true;
                $val = $match[1];
                if (preg_match("/^([a-z]\w*)\($/", $val, $matches)) { // may be func, or variable w/ implicit multiplication against parentheses...
                    if (in_array($matches[1], $this->fb) or array_key_exists($matches[1], $this->f)) { // it's a func
                        $stack->push($val);
                        $stack->push(1);
                        $stack->push('(');
                        $expecting_op = false;
                    } else { // it's a var w/ implicit multiplication
                        $val = $matches[1];
                        $output[] = $val;
                    }
                } else { // it's a plain old var or num
                    $output[] = $val;
                }
                $index += strlen($val);
            //===============
            } elseif ($op == ')') { // miscellaneous error checking
                return $this->trigger("unexpected ')'");
            } elseif (in_array($op, $ops) and !$expecting_op) {
                return $this->trigger("unexpected operator '$op'");
            } else { // I don't even want to know what you did to get here
                return $this->trigger("an unexpected error occured");
            }
            if ($index == strlen($expr)) {
                if (in_array($op, $ops)) { // did we end with an operator? bad.
                    return $this->trigger("operator '$op' lacks operand");
                } else {
                    break;
                }
            }
            while (substr($expr, $index, 1) == ' ') { // step the index past whitespace (pretty much turns whitespace 
                $index++;                             // into implicit multiplication if no operator is there)
            }
        
        } 
        while (!is_null($op = $stack->pop())) { // pop everything off the stack and push onto output
            if ($op == '(') return $this->trigger("expecting ')'"); // if there are (s on the stack, ()s were unbalanced
            $output[] = $op;
        }
        return $output;
    }

    // evaluate postfix notation
    function pfx($tokens, $vars = array()) {      
        if ($tokens == false) return false;    
        $stack = new EvalMathStack;
        foreach ($tokens as $token) { // nice and easy
            // if the token is a binary operator, pop two values off the stack, do the operation, and push the result back on
            if (in_array($token, array('+', '-', '*', '/', '^'))) {
                if (is_null($op2 = $stack->pop())) return $this->trigger("internal error");
                if (is_null($op1 = $stack->pop())) return $this->trigger("internal error");
                switch ($token) {
                    case '+':
                        $stack->push($op1+$op2); break;
                    case '-':
                        $stack->push($op1-$op2); break;
                    case '*':
                        $stack->push($op1*$op2); break;
                    case '/':
                        if ($op2 == 0) return $this->trigger("division by zero");
                        $stack->push($op1/$op2); break;
                    case '^':
                        $stack->push(pow($op1, $op2)); break;
                }
            // if the token is a unary operator, pop one value off the stack, do the operation, and push it back on
            } elseif ($token == "_") {
                $stack->push(-1*$stack->pop());
            // if the token is a function, pop arguments off the stack, hand them to the function, and push the result back on
            } elseif (preg_match("/^([a-z]\w*)\($/", $token, $matches)) { // it's a function!
                $fnn = $matches[1];
                if (in_array($fnn, $this->fb)) { // built-in function:
                    if (is_null($op1 = $stack->pop())) return $this->trigger("internal error");
                    $fnn = preg_replace("/^arc/", "a", $fnn); // for the 'arc' trig synonyms
                    if ($fnn == 'ln') $fnn = 'log';
                    eval('$stack->push(' . $fnn . '($op1));'); // perfectly safe eval()
                } elseif (array_key_exists($fnn, $this->f)) { // user function
                    // get args
                    $args = array();
                    for ($i = count($this->f[$fnn]['args'])-1; $i >= 0; $i--) {
                        if (is_null($args[$this->f[$fnn]['args'][$i]] = $stack->pop())) return $this->trigger("internal error");
                    }
                    $stack->push($this->pfx($this->f[$fnn]['func'], $args)); // yay... recursion!!!!
                }
            // if the token is a number or variable, push it on the stack
            } else {
                if (is_numeric($token)) {
                    $stack->push($token);
                } elseif (array_key_exists($token, $this->v)) {
                    $stack->push($this->v[$token]);
                } elseif (array_key_exists($token, $vars)) {
                    $stack->push($vars[$token]);
                } else {
                    return $this->trigger("undefined variable '$token'");
                }
            }
        }
        // when we're out of tokens, the stack should have a single element, the final result
        if ($stack->count != 1) return $this->trigger("internal error");
        return $stack->pop();
    }
    
    // trigger an error, but nicely, if need be
    function trigger($msg) {
        $this->last_error = $msg;
        if (!$this->suppress_errors) trigger_error($msg, E_USER_WARNING);
        return false;
    }
}

// for internal use
class EvalMathStack {

    var $stack = array();
    var $count = 0;
    
    function push($val) {
        $this->stack[$this->count] = $val;
        $this->count++;
    }
    
    function pop() {
        if ($this->count > 0) {
            $this->count--;
            return $this->stack[$this->count];
        }
        return null;
    }
    
    function last($n=1) {
        return $this->stack[$this->count-$n];
    }
}

function registerm() {
    $class = new algbot;
    register($class, __FILE__, 'AlgBot module', 'AlgBot');
}