"""High-level interface to the EPIC python integration. This module exposes functions and classes that make interfacing your python code with the EPIC irc client more pythonic. Getting Started =============== Before you can load your script the environment must be initialized. We have provided a script for this purpose that works for the most common cases. You can run it by typing "/load python" at the EPIC prompt. If you wish to have the python environment initilized each time you start EPIC you can add "load python" to your `~/.epicrc` file. Quick Examples ============== @alias('epic_command') def epic_command(args): '''A python function working as an epic alias. ''' say('Saying ' + args) say('Version: ' + expression('info(i)')) @on('hook') def on_hook(args): '''A python function working as an epic hook. ''' say('Hooked: ' + args) EPIC For The Python Programmer ============================== EPIC is a fork of the ircii client . It has been actively developed since 1993. It is stable and mature and offers many benefits for both background (bot) usage and as an IRC client. As a client, EPIC offers a robust and well tested TUI. The flexibility of the client allows you to customize the interface in almost every way. Through the use of script packs a user can make her client behave according to a number of different paradigms. As a daemon, EPIC offers a robust and well tested event framework. All you need to worry about is what events you want to react to. EPIC handles the differences between IRC networks and presents them to you in a coherent way. If you run your bot inside screen or tmux you can interactively examine and interact with your code as it's running, making debugging easier. There are three primary ways that your python code will be executed by EPIC: * User typed commands * Event Triggers * Socket Listeners User Typed Commands ------------------- Much like your shell, a command typed at the EPIC prompt has the full power of the ircii language available to it. This allows the user to build powerful constructs on their irc input line, much in the same way shells allow you to build powerful constructs: > /fe (#epic #python) channel { join $channel } You can create your own user-typed commands using the @alias() decorator (explained below.) You can poke around the alias system yourself by typing "/alias", or "/alias " at the EPIC prompt. Event Triggers -------------- An event trigger (aka "on" or "hook") is a piece of code that is executed when an event happens. There are event triggers available for any event that might happen within EPIC. Some of the more common events include connecting to a server, joining a channel, or a message being sent to the user or a channel the user has joined. You can create your own event triggers using the @on() decorator (explained below.) You can look at the existing event triggers by typing "/on" at the EPIC prompt. Socket Listeners --------------- If you want to provide a network service, such as an HTTP or IRC server, you will need to register your listening socket with EPIC. You can do this with the `register_listener_callback()` function or the `SocketServerMixin` class, both explained below. Logging and Output ================== EPIC configures a log handler for you. You don't have to worry about logging details inside your script, simply setup a logger like so: import logging logger = logging.getLogger('my_script') logger.info('Hello, World!') Anything output to STDOUT or STDERR will automatically be captured and output into the user's EPIC window. Classes ======= This module comes with one class. SocketServerMixin ----------------- If you use a server based on Python's `socketserver.BaseRequestHandler` class you can easily hook into EPIC's callback system by using `SocketServerMixin`. Most of the included servers, such as `socketserver.TCPServer` and `http.server.HTTPServer`, work with this mixin. Under the hood `epic.SocketServerMixin` registers a socket callback for your class and overloads `handle_request()` to integrate with EPIC's event loop. Decorators ========== This module comes with two decorators. * @alias(): Register function as a command that can be typed at the prompt * @on(): Register function to be executed when an event happens @alias() -------- When a function is decorated with @alias() it will be executed when the user types the name of your alias. Anything your function returns will be ignored. If you wish to convey information back to the user you will need to use a `logger`, `echo()`, `xecho()`, or `command()`. Alias functions will be called with exactly one argument- a string containing any arguments typed after the command. Example: @alias('hello') def hello(args): xecho('Hello, %s!' % args) When the user types "/hello Python World" it will translate to `hello('Python World')`. All python aliases have a small ircii shim installed. You can examine this shim by typing "/alias hello" at the EPIC prompt. @on() ----- When an event happens EPIC will call any registered event handlers. Events are thrown for basically everything that happens. By the time your client has connected to a server, before it has even joined a channel, dozens of events have been thrown. You use the @on() decorator to register your event handler. An event handler is a function that takes a single argument. When called it will be passed a string containing one or more words corresponding to the event. For now parsing that string is up to each event handler. Example: @on('privmsg', '*enemy ships*', NOISE_QUIET) def enemy_ships(args): xecho("It's a trap!") In this example anytime someone sends a message with the phrase "enemy ships" their client will print out a warning: *** It's a trap! All python event triggers have a small ircii shim installed. You can examine the shim installed for our example by typing "/on privmsg" at the EPIC prompt. Calling EPIC From Python ======================== If you want EPIC to do something for you there are 3 primary ways to do so. xecho() ------- You can use xecho() to output text to one or more of EPIC's windows. Your text is prepended with the default banner by default, but this can be overridden. There are a lot of options that control where (or even if) your text will be output. See the docstring for xecho() for more details. Example: xecho("It's a trap!") command() and evaluate() ------------------------ If you want to execute a command as if the user had typed it at the EPIC prompt you can use either command() or evaluate(). The primary difference between the two is whether EPIC will parse the line and expand any variables or ircii functions it contains. Most of the time you want to use command(), especially if you are passing in untrusted input. This will not do any parsing of the command line. If you use evaluate() EPIC will parse the line first to replace $-strings with their expandos. These functions will always return None. expression() ------------ When you need to get a piece of data from EPIC you can use expression(). EPIC expressions are roughly analogous to python expressions. Within an expression you don't use $ to indicate an expando. Example, check to see if they have logging turned on: expression('LOG') == 'ON' Example, get the channel operators for a channel: chanops = expression('chops(#epic)') Example, get the list of servers you're connected to: servers = expression('myservers()') register_listener_callback() ---------------------------- Due to the way EPIC embeds python your python code will not have its own main loop. To allow network services to work EPIC lets you register a callback for a network socket using `register_listener_callback()`. When new connections come in your callback will be called so you can handle the incoming request. Calling Python from EPIC ======================== There are two primary ways to call Python from within EPIC. You can execute a statement using /python or execute an expression you using $python(). /python ------- You can use /python to execute a python statement from the top-level (__main__) namespace. You can not execute an expression using /python, if you attempt to do so a stack trace will be output to the currently active window. $python() --------- You can use $python() to execute a python expression and get the resulting object back. Strings will be passed as bare strings, any other object type will be passed back as a repr() string. Helpful Aliases --------------- There are a couple helpful aliases you can use when developing. * pyecho: Calls $python() and echos the output to your window * pyload: Imports a python module * pyreload: Re-imports a python module so you don't have to quit the client Everything Else =============== There are a lot of nooks and crannies that are outside the scope of this document. It is hoped that this gives you a good grounding for writing python code that interfaces with EPIC, but it does not talk about how to actually use EPIC. EPIC has a rich feature set which you can access from Python, please take some time to browse the full documentation here: http://epicsol.org/help_root If you want to know more, or just want to chat with like-minded programmers, please come talk to us: Network: EFnet (irc.efnet.net) Channel: #epic Acknowledgements ================ EPIC5 and the low-level Python functionality was written by hop. This document and the high-level Python module was written by skullY. A big thanks to hop for being willing to add "python support that doesn't suck". He has spent many hours both talking to me and learning about how to embed python in his program. Finally, thanks to caf and everyone else in #epic for providing feedback along the way. This integration is stronger for it. """ # FIXME: Remove this NOTES = """ hop said he should implement _epic.set_set(). It exists, but it throws a "not implemented" exception. You can use symbolctl(PMATCH BUILTIN_VARIABLE name) will return an empty string if that set does't exist. You can PMATCH, CREATE, and DELETE. This is the only way to get at some things like builtin variables. """ import logging import sys from importlib import reload from _epic import callback_when_readable, cancel_callback, cmd, eval, expand, expr, echo, say, call from _epic import run_command, call_function, get_set, get_assign, get_var, builtin_cmd # Map some commands to friendlier names command = cmd evaluate = eval expression = expr # Store some potentially useful data EPIC_BINARY_CKSUM = expression('info(s)') EPIC_COMMIT_ID = expression('info(i)') EPIC_COMPILE_INFO = expression('info(c)') EPIC_COMPILE_OPTS = expression('info(o)') EPIC_NEW_MATH_PARSER = expression('info(m)') == '1' EPIC_RELEASE_NAME = expression('info(r)') EPIC_RELEASE_VERSION = expression('info(v)').split(' ', 1)[1].replace(' ', '.') # Noise flags NOISE_DEFAULT = '' NOISE_SILENT = '^' NOISE_QUIET = '-' NOISE_NOISY = '+' NOISE_SYSTEM = '%' # Tracking object for registered socket listeners. # Format: _listening_sockets[] = (, ) _listening_sockets = {} # Classes that help script writers interact with epic class Console(object): """Write a file-like object to the epic console. """ def __init__(self, output_name='PYTHON-CONSOLE'): self.output_name = output_name def write(self, buf): for line in buf.rstrip().splitlines(): if self.output_name: echo("%s: %s" % (self.output_name, line)) else: echo(line) def flush(self): pass class SocketServerMixin(object): """Modify most SocketServers to work with EPIC. Because EPIC is a single-threaded program that controls the main loop, Python code is only run when EPIC calls into it. This mixin overrides `handle_request()` so that EPIC can dispatch to that function when a new connection happens. The listening socket is automatically registered with EPIC's callback system. Set `self.server_name` to change the name reported in log messages. """ def __init__(self, *args, **kwargs): super().__init__(*args, **kwargs) self.server_name = self.__class__.__name__ register_listener_callback(self.socket.fileno(), self.handle_request, self.server_close) def handle_request(self, vfd): """Handle a single request from the parent socket. """ self._handle_request_noblock() self.service_actions() def server_close(self, vfd=None, *args, **kwargs): """Remove the callback and close the parent socket. """ cancel_callback(self.socket.fileno()) super().server_close(*args, **kwargs) # Configure our output sys.stdout = Console('PYTHON-STDOUT') sys.stderr = Console('PYTHON-STDERR') log = logging.getLogger('epic') log.setLevel(logging.DEBUG) log_handler = logging.StreamHandler(Console(None)) log_handler.setLevel(logging.INFO) #log_formatter = logging.Formatter('%(asctime)s: %(name)s: %(levelname)s: %(message)s', '%H:%M:%S') log_formatter = logging.Formatter('%(asctime)s: python.%(module)s: %(message)s', '%H:%M:%S') log_handler.setFormatter(log_formatter) log.addHandler(log_handler) # Functions that epic python scripts can utilize. def set_set(set_key, set_value, *, quiet=True): """Assign a value to a /set in EPIC. A /set is a key-value pair that always exists. """ quiet = '^' if quiet else '' return command('%sSET %s %s' % (quiet, set_key, set_value)) def assign(assign_key, assign_value, *, quiet=True): """Assign a value to a /assign in EPIC. A /assign is a key-value pair that may or may not exist. """ quiet = '^' if quiet else '' return command('%sASSIGN %s %s' % (quiet, set_key, set_value)) def xecho(message, all=False, all_server=False, banner=True, current=False, e=None, f=False, level=None, line=None, nolog=False, raw=False, say=False, target=None, visible=False, window=None, x=False): """Output a line to the user's window. `message` The message to output `all` Output to all windows. `all_server` Output to all windows on the server. `banner` Prefix the message with the current banner `current` Output to current server's current window. This is different from the visible option. `e` After specified number of seconds, echoed line is erased. `f` Do not notify (%F) if the window is hidden. `level` Use the given level to hunt for a window, overriding the current level being used. `line` When used with `win` overwrite a particular line in that window. `nolog` Do not save the message to any log files that might apply. `raw` Output the message as a raw string to the underlying tty. This is used to send control characters to the terminal emulator. `say` Do not output if display is being suppressed. `target` Use the given target to hunt for a window, overriding the current target being used. `visible` Output to a visible window. Usually the current window or the top window on the main screen. `window` Output to the specified window. `x` Overrule `set mangle_display` and pretend it was set to NORMALIZE instead. """ xecho_args = ['xecho'] if all: xecho_args.append('-all') if all_server: xecho_args.append('-as') if banner: xecho_args.append('-b') if current: xecho_args.append('-current') if isinstance(e, int): xecho_args.append('-e %d' % e) if f: xecho_args.append('-f') if isinstance(level, int): xecho_args.append('-level %d' % level) if nolog: xecho_args.append('-nolog') if raw: xecho_args.append('-raw') if say: xecho_args.append('-say') if isinstance(target, int): xecho_args.append('-target %d' % target) if visible: xecho_args.append('-visible') if isinstance(window, int): xecho_args.append('-window %d' % window) if isinstance(line, int): xecho_args.append('-line %d' % line) if x: xecho_args.append('-x') # Print the message xecho_args.append('--') xecho_args.append(message) command(' '.join(xecho_args)) # Decorators for registering python functions as aliases or hooks def alias(name): """A decorator used to register an epic alias. Epic aliases will always be called with a single argument, and that argument will be a string. Aliases are responsible for doing their own argument parsing. """ def decorator(f): module = f.__module__ function = f.__name__ command("alias %s {pydirect %s.%s $*}" % (name, module, function)) expression("symbolctl(SET %s 0 ALIAS PACKAGE %s.py)" % (function, module)) return f return decorator def on(event_type, wildcard_pattern='*', noise_indicator=NOISE_SILENT, exclude_match=False, delete=False, serial_number='-', flexible_pattern=False): """A decorator used to register an epic event handler. For complete detail about how epic event handlers work consult the epic5 documentation: Uniqueness ---------- ONs have to be “unique”. The primary key of an ON is: * Event Type * Serial Number * Wildcard Pattern That means every ON has to have these three pieces of information. Creating an ON is like an “upsert” – if there is not an existing ON, you will create it. If there is an existing ON, you will update it. If you do not provide a serial number one will be selected for you. Serial Numbers -------------- Every ON has a serial number. The default is '-'. You will want to choose a unique serial number for your script or leave the default, which will automatically choose an unused serial number less than 0. For each serial number at most one `@on()` will be executed. EPIC will determine the best match among the available Wildcard Patterns and execute only that hook. Serial numbers are executed in order. Serial number 0 is special in that it can supress EPIC's default output for a hook, see the full documentation for /on for more detail: Arguments --------- `event_type` The event that we're hooking, EG: PUBLIC or MSGS. The full list of possible event types is on , and can by found by looking for the pages that start with `on_`. `wildcard_pattern` The pattern you want to match. Within a pattern * matches any text while % matches any text until a space is encountered. `exclude_match` When True the `wildcard_pattern` is treated as an exclusion rather than a match. `delete` When True delete any matching hooks. `serial_number` The serial number for this hook. Use '-' to select the next unused number below 0, '+' to select the next unused number above 0, or specify your own integer here. `noise_indicator` A flag indicating how noisy this hook should be. By default all hooks will output all echoed messages plus an alert, "ON hooked by ...". * NOISE_DEFAULT: Show the echoed output plus the alert. * NOISE_SILENT: suppress all output, do not run the *default action*. * NOISE_QUIET: suppress all output, run the *default action*. * NOISE_NOISY: show all output * NOISE_SYSTEM: display echoed output and supress the *default action* `flexible_pattern` When true the `wildcard_pattern` will be expanded every time the hook is matched. When false the `wildcard_pattern` will be matched as is. """ if serial_number: sni = '#' serial_number = ' ' + str(serial_number) else: sni = '' serial_number = '' delete = '-' if delete else '' exclude_match = '!' if exclude_match else '' quote_type = "'" if flexible_pattern else '"' if noise_indicator not in (NOISE_DEFAULT, NOISE_SILENT, NOISE_QUIET, NOISE_NOISY, NOISE_SYSTEM): echo('Unknown noise_indicator %s' % noise_indicator) noise_indicator = NOISE_DEFAULT def decorator(f): log.debug("on %s%s%s%s %s%s%s%s%s {pydirect %s.%s $*}", sni, noise_indicator, event_type, serial_number, exclude_match, delete, quote_type, wildcard_pattern, quote_type, f.__module__, f.__name__ ) command("on %s%s%s%s %s%s%s%s%s {pydirect %s.%s $*}" % ( sni, noise_indicator, event_type, serial_number, exclude_match, delete, quote_type, wildcard_pattern, quote_type, f.__module__, f.__name__ )) return f return decorator def register_listener_callback(fd, dispatch_function, cleanup_function): """Register a dispatch and a cleanup function for a listening file descriptor. """ log.debug( 'register_listener_callback(fd=%d, dispatch_function=%s, cleanup_function=%s)', fd, dispatch_function.__name__, cleanup_function.__name__ ) if fd in _listening_sockets: xecho('FD already registered: %d' % fd) return False callback_when_readable(fd, dispatch_function, cleanup_function, 0) _listening_sockets[fd] = (dispatch_function, cleanup_function) return True # Internal use functions @on('exit') def cleanup_listener_callbacks(args): """Called by our exit hook to close up our servers. """ log.debug('cleanup_listener_callbacks(args=%s)', repr(args)) for fd, funcs in _listening_sockets.items(): cancel_callback(fd) funcs[1]() # Run the cleanup function @alias('update_python_path') def update_python_path(args): split_args = args.split() old_load_path = split_args[0].split(':') new_load_path = split_args[1].split(':') sys_path = sys.path.copy() if len(split_args) > 2: xecho("Warning: Extra arguments passed to update_load_path() are ignored!", banner=True) # Remove paths that don't appear in new_load_path if old_load_path: for path in old_load_path: if path not in new_load_path: sys_path.remove(path) # Add paths that are not in sys_path yet for path in new_load_path: if path not in sys_path: sys_path.append(path) # Replace sys.path with our new version sys.path[:] = sys_path