1 files changed, 312 insertions, 0 deletions
diff --git a/plugins/zyklonb/eval b/plugins/zyklonb/eval
new file mode 100755
index 0000000..982d78b
--- /dev/null
+++ b/plugins/zyklonb/eval
@@ -0,0 +1,312 @@
+#!/usr/bin/awk -f
+#
+# ZyklonB eval plugin, LISP-like expression evaluator
+#
+# Copyright 2013, 2014 Přemysl Janouch
+# See the file LICENSE for licensing information.
+#
+
+BEGIN \
+{
+	RS = "\r"
+	ORS = "\r\n"
+	IGNORECASE = 1
+	srand()
+
+	prefix = get_config("prefix")
+
+	print "ZYKLONB register"
+	fflush("")
+
+	# All functions have to be in this particular array
+	min_args["int"]    = 1
+	min_args["+"]      = 1
+	min_args["-"]      = 1
+	min_args["*"]      = 1
+	min_args["/"]      = 1
+	min_args["%"]      = 1
+	min_args["^"]      = 1
+	min_args["**"]     = 1
+	min_args["exp"]    = 1
+	min_args["sin"]    = 1
+	min_args["cos"]    = 1
+	min_args["atan2"]  = 2
+	min_args["log"]    = 1
+	min_args["rand"]   = 0
+	min_args["sqrt"]   = 1
+
+	min_args["pi"]     = 0
+	min_args["e"]      = 0
+
+	min_args["min"]    = 1
+	min_args["max"]    = 1
+
+	# Whereas here their presence is only optional
+	max_args["int"]    = 1
+	max_args["sin"]    = 1
+	max_args["cos"]    = 1
+	max_args["atan2"]  = 2
+	max_args["log"]    = 1
+	max_args["rand"]   = 0
+	max_args["sqrt"]   = 1
+
+	max_args["pi"]     = 0
+	max_args["e"]      = 0
+}
+
+{
+	parse($0)
+}
+
+msg_command == "PRIVMSG" \
+{
+	# Context = either channel or user nickname
+	match(msg_prefix, /^[^!]+/)
+	ctx = substr(msg_prefix, RSTART, RLENGTH)
+	if (msg_param[0] ~ /^[#&!+]/)
+	{
+		ctx_quote = ctx ": "
+		ctx = msg_param[0]
+	}
+	else
+		ctx_quote = ""
+
+
+	if (substr(msg_param[1], 1, length(prefix)) == prefix)
+	{
+		keyword = "eval"
+		text = substr(msg_param[1], 1 + length(prefix))
+	 	if (match(text, "^" keyword "([^A-Za-z0-9].*|$)"))
+			process_request(substr(text, 1 + length(keyword)))
+	}
+}
+
+{
+	fflush("")
+}
+
+function pmrespond (text)
+{
+	print "PRIVMSG " ctx " :" ctx_quote text
+}
+
+function process_request (input,    res, x)
+{
+	delete funs
+	delete accumulator
+	delete n_args
+
+	res = ""
+	fun_top = 0
+	funs[0] = ""
+	accumulator[0] = 0
+	n_args[0] = 0
+
+	if (match(input, "^[ \t]*"))
+		input = substr(input, RLENGTH + 1)
+	if (input == "")
+		res = "expression missing"
+
+	while (res == "" && input != "") {
+		if (match(input, "^-?[0-9]+\\.?[0-9]*")) {
+			x = substr(input, RSTART, RLENGTH)
+			input = substr(input, RLENGTH + 1)
+
+			match(input, "^ *")
+			input = substr(input, RLENGTH + 1)
+
+			res = process_argument(x)
+		} else if (match(input, "^[(]([^ ()]+)")) {
+			x = substr(input, RSTART + 1, RLENGTH - 1)
+			input = substr(input, RLENGTH + 1)
+
+			match(input, "^ *")
+			input = substr(input, RLENGTH + 1)
+
+			if (!(x in min_args)) {
+				res = "undefined function '" x "'"
+			} else {
+				fun_top++
+				funs[fun_top] = x
+				accumulator[fun_top] = 636363
+				n_args[fun_top] = 0
+			}
+		} else if (match(input, "^[)] *")) {
+			input = substr(input, RLENGTH + 1)
+			res = process_end()
+		} else
+			res = "invalid input at '" substr(input, 1, 10) "...'"
+	}
+
+	if (res == "") {
+		if (fun_top != 0)
+			res = "unclosed '" funs[fun_top] "'"
+		else if (n_args[0] != 1)
+			res = "internal error, expected one result" \
+				", got " n_args[0] " instead"
+	}
+
+	if (res == "")
+		pmrespond(accumulator[0])
+	else
+		pmrespond(res)
+}
+
+function process_argument (arg)
+{
+	if (fun_top == 0) {
+		if (n_args[0]++ != 0)
+			return "too many results, I only expect one"
+
+		accumulator[0] = arg
+		return ""
+	}
+
+	fun = funs[fun_top]
+	if (fun in max_args && max_args[fun] <= n_args[fun_top])
+		return "too many operands for " fun
+
+	if (fun == "int") {
+		accumulator[fun_top] = int(arg)
+	} else if (fun == "+") {
+		if (n_args[fun_top] == 0)
+			accumulator[fun_top] = arg
+		else
+			accumulator[fun_top] += arg
+	} else if (fun == "-") {
+		if (n_args[fun_top] == 0)
+			accumulator[fun_top] = arg
+		else
+			accumulator[fun_top] -= arg
+	} else if (fun == "*") {
+		if (n_args[fun_top] == 0)
+			accumulator[fun_top] = arg
+		else
+			accumulator[fun_top] *= arg
+	} else if (fun == "/") {
+		if (n_args[fun_top] == 0)
+			accumulator[fun_top] = arg
+		else if (arg == 0)
+			return "division by zero"
+		else
+			accumulator[fun_top] /= arg
+	} else if (fun == "%") {
+		if (n_args[fun_top] == 0)
+			accumulator[fun_top] = arg
+		else if (arg == 0)
+			return "division by zero"
+		else
+			accumulator[fun_top] %= arg
+	} else if (fun == "^" || fun == "**" || fun == "exp") {
+		if (n_args[fun_top] == 0)
+			accumulator[fun_top] = arg
+		else
+			accumulator[fun_top] ^= arg
+	} else if (fun == "sin") {
+		accumulator[fun_top] = sin(arg)
+	} else if (fun == "cos") {
+		accumulator[fun_top] = cos(arg)
+	} else if (fun == "atan2") {
+		if (n_args[fun_top] == 0)
+			accumulator[fun_top] = arg
+		else
+			accumulator[fun_top] = atan2(accumulator[fun_top], arg)
+	} else if (fun == "log") {
+		accumulator[fun_top] = log(arg)
+	} else if (fun == "rand") {
+		# Just for completeness, execution never gets here
+	} else if (fun == "sqrt") {
+		accumulator[fun_top] = sqrt(arg)
+	} else if (fun == "min") {
+		if (n_args[fun_top] == 0)
+			accumulator[fun_top] = arg
+		else if (accumulator[fun_top] > arg)
+			accumulator[fun_top] = arg
+	} else if (fun == "max") {
+		if (n_args[fun_top] == 0)
+			accumulator[fun_top] = arg
+		else if (accumulator[fun_top] < arg)
+			accumulator[fun_top] = arg
+	} else
+		return "internal error, unhandled operands for " fun
+
+	n_args[fun_top]++
+	return ""
+}
+
+function process_end ()
+{
+	if (fun_top <= 0)
+		return "extraneous ')'"
+
+	fun = funs[fun_top]
+	if (!(fun in min_args))
+		return "internal error, unhandled ')' for '" fun "'"
+	if (min_args[fun] > n_args[fun_top])
+		return "not enough operands for '" fun "'"
+
+	# There's no 'init' function to do it in
+	if (fun == "rand")
+		accumulator[fun_top] = rand()
+	else if (fun == "pi")
+		accumulator[fun_top] = 3.141592653589793
+	else if (fun == "e")
+		accumulator[fun_top] = 2.718281828459045
+
+	return process_argument(accumulator[fun_top--])
+}
+
+function get_config (key)
+{
+	print "ZYKLONB get_config :" key
+	fflush("")
+
+	getline
+	parse($0)
+	return msg_param[0]
+}
+
+function parse (line,     s, n, id, token)
+{
+	s = 1
+	id = 0
+
+	# NAWK only uses the first character of RS
+	if (line ~ /^\n/)
+		line = substr(line, 2)
+
+	msg_prefix = ""
+	msg_command = ""
+	delete msg_param
+
+	n = match(substr(line, s), / |$/)
+	while (n)
+	{
+		token = substr(line, s, n - 1)
+		if (token ~ /^:/)
+		{
+			if (s == 1)
+				msg_prefix = substr(token, 2)
+			else
+			{
+				msg_param[id] = substr(line, s + 1)
+				break
+			}
+		}
+		else if (!msg_command)
+			msg_command = toupper(token)
+		else
+			msg_param[id++] = token
+
+		s = s + n
+		n = index(substr(line, s), " ")
+
+		if (!n)
+		{
+		       n = length(substr(line, s)) + 1
+		       if (n == 1)
+			       break;
+		}
+	}
+}
+