# Copyright (c) 2002-2005 ActiveState Corp. # License: MIT (see LICENSE.txt for license details) # Author: Trent Mick (TrentM@ActiveState.com) # Home: http://trentm.com/projects/cmdln/ """An improvement on Python's standard cmd.py module. As with cmd.py, this module provides "a simple framework for writing line-oriented command intepreters." This module provides a 'RawCmdln' class that fixes some design flaws in cmd.Cmd, making it more scalable and nicer to use for good 'cvs'- or 'svn'-style command line interfaces or simple shells. And it provides a 'Cmdln' class that add optparse-based option processing. Basically you use it like this: import cmdln class MySVN(cmdln.Cmdln): name = "svn" @cmdln.alias('stat', 'st') @cmdln.option('-v', '--verbose', action='store_true' help='print verbose information') def do_status(self, subcmd, opts, *paths): print "handle 'svn status' command" #... if __name__ == "__main__": shell = MySVN() retval = shell.main() sys.exit(retval) See the README.txt or for more details. """ __revision__ = "$Id: cmdln.py 1666 2007-05-09 03:13:03Z trentm $" __version_info__ = (1, 0, 0) __version__ = '.'.join(map(str, __version_info__)) import os import re import cmd import optparse from pprint import pprint from datetime import date #---- globals LOOP_ALWAYS, LOOP_NEVER, LOOP_IF_EMPTY = range(3) # An unspecified optional argument when None is a meaningful value. _NOT_SPECIFIED = ("Not", "Specified") # Pattern to match a TypeError message from a call that # failed because of incorrect number of arguments (see # Python/getargs.c). _INCORRECT_NUM_ARGS_RE = re.compile( r"(takes [\w ]+ )(\d+)( arguments? \()(\d+)( given\))") # Static bits of man page MAN_HEADER = r""".TH %(ucname)s "1" "%(date)s" "%(name)s %(version)s" "User Commands" .SH NAME %(name)s \- Program to do useful things. .SH SYNOPSIS .B %(name)s [\fIGLOBALOPTS\fR] \fISUBCOMMAND \fR[\fIOPTS\fR] [\fIARGS\fR...] .br .B %(name)s \fIhelp SUBCOMMAND\fR .SH DESCRIPTION """ MAN_COMMANDS_HEADER = r""" .SS COMMANDS """ MAN_OPTIONS_HEADER = r""" .SS GLOBAL OPTIONS """ MAN_FOOTER = r""" .SH AUTHOR This man page is automatically generated. """ #---- exceptions class CmdlnError(Exception): """A cmdln.py usage error.""" def __init__(self, msg): self.msg = msg def __str__(self): return self.msg class CmdlnUserError(Exception): """An error by a user of a cmdln-based tool/shell.""" pass #---- public methods and classes def alias(*aliases): """Decorator to add aliases for Cmdln.do_* command handlers. Example: class MyShell(cmdln.Cmdln): @cmdln.alias("!", "sh") def do_shell(self, argv): #...implement 'shell' command """ def decorate(f): if not hasattr(f, "aliases"): f.aliases = [] f.aliases += aliases return f return decorate class RawCmdln(cmd.Cmd): """An improved (on cmd.Cmd) framework for building multi-subcommand scripts (think "svn" & "cvs") and simple shells (think "pdb" and "gdb"). A simple example: import cmdln class MySVN(cmdln.RawCmdln): name = "svn" @cmdln.aliases('stat', 'st') def do_status(self, argv): print "handle 'svn status' command" if __name__ == "__main__": shell = MySVN() retval = shell.main() sys.exit(retval) See for more information. """ name = None # if unset, defaults basename(sys.argv[0]) prompt = None # if unset, defaults to self.name+"> " version = None # if set, default top-level options include --version # Default messages for some 'help' command error cases. # They are interpolated with one arg: the command. nohelp = "no help on '%s'" unknowncmd = "unknown command: '%s'" helpindent = '' # string with which to indent help output # Default man page parts, please change them in subclass man_header = MAN_HEADER man_commands_header = MAN_COMMANDS_HEADER man_options_header = MAN_OPTIONS_HEADER man_footer = MAN_FOOTER def __init__(self, completekey='tab', stdin=None, stdout=None, stderr=None): """Cmdln(completekey='tab', stdin=None, stdout=None, stderr=None) The optional argument 'completekey' is the readline name of a completion key; it defaults to the Tab key. If completekey is not None and the readline module is available, command completion is done automatically. The optional arguments 'stdin', 'stdout' and 'stderr' specify alternate input, output and error output file objects; if not specified, sys.* are used. If 'stdout' but not 'stderr' is specified, stdout is used for error output. This is to provide least surprise for users used to only the 'stdin' and 'stdout' options with cmd.Cmd. """ import sys if self.name is None: self.name = os.path.basename(sys.argv[0]) if self.prompt is None: self.prompt = self.name+"> " self._name_str = self._str(self.name) self._prompt_str = self._str(self.prompt) if stdin is not None: self.stdin = stdin else: self.stdin = sys.stdin if stdout is not None: self.stdout = stdout else: self.stdout = sys.stdout if stderr is not None: self.stderr = stderr elif stdout is not None: self.stderr = stdout else: self.stderr = sys.stderr self.cmdqueue = [] self.completekey = completekey self.cmdlooping = False def get_optparser(self): """Hook for subclasses to set the option parser for the top-level command/shell. This option parser is used retrieved and used by `.main()' to handle top-level options. The default implements a single '-h|--help' option. Sub-classes can return None to have no options at the top-level. Typically an instance of CmdlnOptionParser should be returned. """ version = (self.version is not None and "%s %s" % (self._name_str, self.version) or None) return CmdlnOptionParser(self, version=version) def get_version(self): """ Returns version of program. To be replaced in subclass. """ return __version__ def postoptparse(self): """Hook method executed just after `.main()' parses top-level options. When called `self.values' holds the results of the option parse. """ pass def main(self, argv=None, loop=LOOP_NEVER): """A possible mainline handler for a script, like so: import cmdln class MyCmd(cmdln.Cmdln): name = "mycmd" ... if __name__ == "__main__": MyCmd().main() By default this will use sys.argv to issue a single command to 'MyCmd', then exit. The 'loop' argument can be use to control interactive shell behaviour. Arguments: "argv" (optional, default sys.argv) is the command to run. It must be a sequence, where the first element is the command name and subsequent elements the args for that command. "loop" (optional, default LOOP_NEVER) is a constant indicating if a command loop should be started (i.e. an interactive shell). Valid values (constants on this module): LOOP_ALWAYS start loop and run "argv", if any LOOP_NEVER run "argv" (or .emptyline()) and exit LOOP_IF_EMPTY run "argv", if given, and exit; otherwise, start loop """ if argv is None: import sys argv = sys.argv else: argv = argv[:] # don't modify caller's list self.optparser = self.get_optparser() if self.optparser: # i.e. optparser=None means don't process for opts try: self.options, args = self.optparser.parse_args(argv[1:]) except CmdlnUserError, ex: msg = "%s: %s\nTry '%s help' for info.\n"\ % (self.name, ex, self.name) self.stderr.write(self._str(msg)) self.stderr.flush() return 1 except StopOptionProcessing, ex: return 0 else: self.options, args = None, argv[1:] self.postoptparse() if loop == LOOP_ALWAYS: if args: self.cmdqueue.append(args) return self.cmdloop() elif loop == LOOP_NEVER: if args: return self.cmd(args) else: return self.emptyline() elif loop == LOOP_IF_EMPTY: if args: return self.cmd(args) else: return self.cmdloop() def cmd(self, argv): """Run one command and exit. "argv" is the arglist for the command to run. argv[0] is the command to run. If argv is an empty list then the 'emptyline' handler is run. Returns the return value from the command handler. """ assert isinstance(argv, (list, tuple)), \ "'argv' is not a sequence: %r" % argv retval = None try: argv = self.precmd(argv) retval = self.onecmd(argv) self.postcmd(argv) except: if not self.cmdexc(argv): raise retval = 1 return retval def _str(self, s): """Safely convert the given str/unicode to a string for printing.""" try: return str(s) except UnicodeError: #XXX What is the proper encoding to use here? 'utf-8' seems # to work better than "getdefaultencoding" (usually # 'ascii'), on OS X at least. #import sys #return s.encode(sys.getdefaultencoding(), "replace") return s.encode("utf-8", "replace") def cmdloop(self, intro=None): """Repeatedly issue a prompt, accept input, parse into an argv, and dispatch (via .precmd(), .onecmd() and .postcmd()), passing them the argv. In other words, start a shell. "intro" (optional) is a introductory message to print when starting the command loop. This overrides the class "intro" attribute, if any. """ self.cmdlooping = True self.preloop() if intro is None: intro = self.intro if intro: intro_str = self._str(intro) self.stdout.write(intro_str+'\n') self.stop = False retval = None while not self.stop: if self.cmdqueue: argv = self.cmdqueue.pop(0) assert isinstance(argv, (list, tuple)), \ "item on 'cmdqueue' is not a sequence: %r" % argv else: if self.use_rawinput: try: line = raw_input(self._prompt_str) except EOFError: line = 'EOF' else: self.stdout.write(self._prompt_str) self.stdout.flush() line = self.stdin.readline() if not len(line): line = 'EOF' else: line = line[:-1] # chop '\n' argv = line2argv(line) try: argv = self.precmd(argv) retval = self.onecmd(argv) self.postcmd(argv) except: if not self.cmdexc(argv): raise retval = 1 self.lastretval = retval self.postloop() self.cmdlooping = False return retval def precmd(self, argv): """Hook method executed just before the command argv is interpreted, but after the input prompt is generated and issued. "argv" is the cmd to run. Returns an argv to run (i.e. this method can modify the command to run). """ return argv def postcmd(self, argv): """Hook method executed just after a command dispatch is finished. "argv" is the command that was run. """ pass def cmdexc(self, argv): """Called if an exception is raised in any of precmd(), onecmd(), or postcmd(). If True is returned, the exception is deemed to have been dealt with. Otherwise, the exception is re-raised. The default implementation handles CmdlnUserError's, which typically correspond to user error in calling commands (as opposed to programmer error in the design of the script using cmdln.py). """ import sys type, exc, traceback = sys.exc_info() if isinstance(exc, CmdlnUserError): msg = "%s %s: %s\nTry '%s help %s' for info.\n"\ % (self.name, argv[0], exc, self.name, argv[0]) self.stderr.write(self._str(msg)) self.stderr.flush() return True def onecmd(self, argv): if not argv: return self.emptyline() self.lastcmd = argv cmdname = self._get_canonical_cmd_name(argv[0]) if cmdname: handler = self._get_cmd_handler(cmdname) if handler: return self._dispatch_cmd(handler, argv) return self.default(argv) def _dispatch_cmd(self, handler, argv): return handler(argv) def default(self, argv): """Hook called to handle a command for which there is no handler. "argv" is the command and arguments to run. The default implementation writes and error message to stderr and returns an error exit status. Returns a numeric command exit status. """ errmsg = self._str(self.unknowncmd % (argv[0],)) if self.cmdlooping: self.stderr.write(errmsg+"\n") else: self.stderr.write("%s: %s\nTry '%s help' for info.\n" % (self._name_str, errmsg, self._name_str)) self.stderr.flush() return 1 def parseline(self, line): # This is used by Cmd.complete (readline completer function) to # massage the current line buffer before completion processing. # We override to drop special '!' handling. line = line.strip() if not line: return None, None, line elif line[0] == '?': line = 'help ' + line[1:] i, n = 0, len(line) while i < n and line[i] in self.identchars: i = i+1 cmd, arg = line[:i], line[i:].strip() return cmd, arg, line def helpdefault(self, cmd, known): """Hook called to handle help on a command for which there is no help handler. "cmd" is the command name on which help was requested. "known" is a boolean indicating if this command is known (i.e. if there is a handler for it). Returns a return code. """ if known: msg = self._str(self.nohelp % (cmd,)) if self.cmdlooping: self.stderr.write(msg + '\n') else: self.stderr.write("%s: %s\n" % (self.name, msg)) else: msg = self.unknowncmd % (cmd,) if self.cmdlooping: self.stderr.write(msg + '\n') else: self.stderr.write("%s: %s\n" "Try '%s help' for info.\n" % (self.name, msg, self.name)) self.stderr.flush() return 1 def do_help(self, argv): """${cmd_name}: give detailed help on a specific sub-command usage: ${name} help [SUBCOMMAND] """ if len(argv) > 1: # asking for help on a particular command doc = None cmdname = self._get_canonical_cmd_name(argv[1]) or argv[1] if not cmdname: return self.helpdefault(argv[1], False) else: helpfunc = getattr(self, "help_"+cmdname, None) if helpfunc: doc = helpfunc() else: handler = self._get_cmd_handler(cmdname) if handler: doc = handler.__doc__ if doc is None: return self.helpdefault(argv[1], handler != None) else: # bare "help" command doc = self.__class__.__doc__ # try class docstring if doc is None: # Try to provide some reasonable useful default help. if self.cmdlooping: prefix = "" else: prefix = self.name+' ' doc = """usage: %sSUBCOMMAND [ARGS...] %shelp [SUBCOMMAND] ${option_list} ${command_list} ${help_list} """ % (prefix, prefix) cmdname = None if doc: # *do* have help content, massage and print that doc = self._help_reindent(doc) doc = self._help_preprocess(doc, cmdname) doc = doc.rstrip() + '\n' # trim down trailing space self.stdout.write(self._str(doc)) self.stdout.flush() do_help.aliases = ["?"] def do_man(self, argv): """${cmd_name}: generates a man page usage: ${name} man """ self.stdout.write(self.man_header % { 'date': date.today().strftime('%b %Y'), 'version': self.get_version(), 'name': self.name, 'ucname': self.name.upper() } ) self.stdout.write(self.man_commands_header) commands = self._help_get_command_list() for command, doc in commands: cmdname = command.split(' ')[0] text = self._help_preprocess(doc, cmdname) lines = [] for line in text.splitlines(False): if line[:8] == ' ' * 8: line = line[8:] lines.append(line) self.stdout.write('.TP\n\\fB%s\\fR\n%s\n' % (command, '\n'.join(lines))) self.stdout.write(self.man_options_header) self.stdout.write(self._help_preprocess('${option_list}', None)) self.stdout.write(self.man_footer) self.stdout.flush() def _help_reindent(self, help, indent=None): """Hook to re-indent help strings before writing to stdout. "help" is the help content to re-indent "indent" is a string with which to indent each line of the help content after normalizing. If unspecified or None then the default is use: the 'self.helpindent' class attribute. By default this is the empty string, i.e. no indentation. By default, all common leading whitespace is removed and then the lot is indented by 'self.helpindent'. When calculating the common leading whitespace the first line is ignored -- hence help content for Conan can be written as follows and have the expected indentation: def do_crush(self, ...): '''${cmd_name}: crush your enemies, see them driven before you... c.f. Conan the Barbarian''' """ if indent is None: indent = self.helpindent lines = help.splitlines(0) _dedentlines(lines, skip_first_line=True) lines = [(indent+line).rstrip() for line in lines] return '\n'.join(lines) def _help_preprocess(self, help, cmdname): """Hook to preprocess a help string before writing to stdout. "help" is the help string to process. "cmdname" is the canonical sub-command name for which help is being given, or None if the help is not specific to a command. By default the following template variables are interpolated in help content. (Note: these are similar to Python 2.4's string.Template interpolation but not quite.) ${name} The tool's/shell's name, i.e. 'self.name'. ${option_list} A formatted table of options for this shell/tool. ${command_list} A formatted table of available sub-commands. ${help_list} A formatted table of additional help topics (i.e. 'help_*' methods with no matching 'do_*' method). ${cmd_name} The name (and aliases) for this sub-command formatted as: "NAME (ALIAS1, ALIAS2, ...)". ${cmd_usage} A formatted usage block inferred from the command function signature. ${cmd_option_list} A formatted table of options for this sub-command. (This is only available for commands using the optparse integration, i.e. using @cmdln.option decorators or manually setting the 'optparser' attribute on the 'do_*' method.) Returns the processed help. """ preprocessors = { "${name}": self._help_preprocess_name, "${option_list}": self._help_preprocess_option_list, "${command_list}": self._help_preprocess_command_list, "${help_list}": self._help_preprocess_help_list, "${cmd_name}": self._help_preprocess_cmd_name, "${cmd_usage}": self._help_preprocess_cmd_usage, "${cmd_option_list}": self._help_preprocess_cmd_option_list, } for marker, preprocessor in preprocessors.items(): if marker in help: help = preprocessor(help, cmdname) return help def _help_preprocess_name(self, help, cmdname=None): return help.replace("${name}", self.name) def _help_preprocess_option_list(self, help, cmdname=None): marker = "${option_list}" indent, indent_width = _get_indent(marker, help) suffix = _get_trailing_whitespace(marker, help) if self.optparser: # Setup formatting options and format. # - Indentation of 4 is better than optparse default of 2. # C.f. Damian Conway's discussion of this in Perl Best # Practices. self.optparser.formatter.indent_increment = 4 self.optparser.formatter.current_indent = indent_width block = self.optparser.format_option_help() + '\n' else: block = "" help = help.replace(indent+marker+suffix, block, 1) return help def _help_get_command_list(self): # Find any aliases for commands. token2canonical = self._get_canonical_map() aliases = {} for token, cmdname in token2canonical.items(): if token == cmdname: continue aliases.setdefault(cmdname, []).append(token) # Get the list of (non-hidden) commands and their # documentation, if any. cmdnames = {} # use a dict to strip duplicates for attr in self.get_names(): if attr.startswith("do_"): cmdnames[attr[3:]] = True cmdnames = cmdnames.keys() cmdnames.sort() linedata = [] for cmdname in cmdnames: if aliases.get(cmdname): a = aliases[cmdname] a.sort() cmdstr = "%s (%s)" % (cmdname, ", ".join(a)) else: cmdstr = cmdname doc = None try: helpfunc = getattr(self, 'help_'+cmdname) except AttributeError: handler = self._get_cmd_handler(cmdname) if handler: doc = handler.__doc__ else: doc = helpfunc() # Strip "${cmd_name}: " from the start of a command's doc. Best # practice dictates that command help strings begin with this, but # it isn't at all wanted for the command list. to_strip = "${cmd_name}:" if doc and doc.startswith(to_strip): #log.debug("stripping %r from start of %s's help string", # to_strip, cmdname) doc = doc[len(to_strip):].lstrip() if not getattr(self._get_cmd_handler(cmdname), "hidden", None): linedata.append( (cmdstr, doc) ) return linedata def _help_preprocess_command_list(self, help, cmdname=None): marker = "${command_list}" indent, indent_width = _get_indent(marker, help) suffix = _get_trailing_whitespace(marker, help) linedata = self._help_get_command_list() if linedata: subindent = indent + ' '*4 lines = _format_linedata(linedata, subindent, indent_width+4) block = indent + "commands:\n" \ + '\n'.join(lines) + "\n\n" help = help.replace(indent+marker+suffix, block, 1) return help def _help_preprocess_help_list(self, help, cmdname=None): marker = "${help_list}" indent, indent_width = _get_indent(marker, help) suffix = _get_trailing_whitespace(marker, help) # Determine the additional help topics, if any. helpnames = {} token2cmdname = self._get_canonical_map() for attr in self.get_names(): if not attr.startswith("help_"): continue helpname = attr[5:] if helpname not in token2cmdname: helpnames[helpname] = True if helpnames: helpnames = helpnames.keys() helpnames.sort() linedata = [(self.name+" help "+n, "") for n in helpnames] subindent = indent + ' '*4 lines = _format_linedata(linedata, subindent, indent_width+4) block = indent + "additional help topics:\n" \ + '\n'.join(lines) + "\n\n" else: block = '' help = help.replace(indent+marker+suffix, block, 1) return help def _help_preprocess_cmd_name(self, help, cmdname=None): marker = "${cmd_name}" handler = self._get_cmd_handler(cmdname) if not handler: raise CmdlnError("cannot preprocess '%s' into help string: " "could not find command handler for %r" % (marker, cmdname)) s = cmdname if hasattr(handler, "aliases"): s += " (%s)" % (", ".join(handler.aliases)) help = help.replace(marker, s) return help #TODO: this only makes sense as part of the Cmdln class. # Add hooks to add help preprocessing template vars and put # this one on that class. def _help_preprocess_cmd_usage(self, help, cmdname=None): marker = "${cmd_usage}" handler = self._get_cmd_handler(cmdname) if not handler: raise CmdlnError("cannot preprocess '%s' into help string: " "could not find command handler for %r" % (marker, cmdname)) indent, indent_width = _get_indent(marker, help) suffix = _get_trailing_whitespace(marker, help) # Extract the introspection bits we need. func = handler.im_func if func.func_defaults: func_defaults = list(func.func_defaults) else: func_defaults = [] co_argcount = func.func_code.co_argcount co_varnames = func.func_code.co_varnames co_flags = func.func_code.co_flags CO_FLAGS_ARGS = 4 CO_FLAGS_KWARGS = 8 # Adjust argcount for possible *args and **kwargs arguments. argcount = co_argcount if co_flags & CO_FLAGS_ARGS: argcount += 1 if co_flags & CO_FLAGS_KWARGS: argcount += 1 # Determine the usage string. usage = "%s %s" % (self.name, cmdname) if argcount <= 2: # handler ::= do_FOO(self, argv) usage += " [ARGS...]" elif argcount >= 3: # handler ::= do_FOO(self, subcmd, opts, ...) argnames = list(co_varnames[3:argcount]) tail = "" if co_flags & CO_FLAGS_KWARGS: name = argnames.pop(-1) import warnings # There is no generally accepted mechanism for passing # keyword arguments from the command line. Could # *perhaps* consider: arg=value arg2=value2 ... warnings.warn("argument '**%s' on '%s.%s' command " "handler will never get values" % (name, self.__class__.__name__, func.func_name)) if co_flags & CO_FLAGS_ARGS: name = argnames.pop(-1) tail = "[%s...]" % name.upper() while func_defaults: func_defaults.pop(-1) name = argnames.pop(-1) tail = "[%s%s%s]" % (name.upper(), (tail and ' ' or ''), tail) while argnames: name = argnames.pop(-1) tail = "%s %s" % (name.upper(), tail) usage += ' ' + tail block_lines = [ self.helpindent + "usage:", self.helpindent + ' '*4 + usage ] block = '\n'.join(block_lines) + '\n\n' help = help.replace(indent+marker+suffix, block, 1) return help #TODO: this only makes sense as part of the Cmdln class. # Add hooks to add help preprocessing template vars and put # this one on that class. def _help_preprocess_cmd_option_list(self, help, cmdname=None): marker = "${cmd_option_list}" handler = self._get_cmd_handler(cmdname) if not handler: raise CmdlnError("cannot preprocess '%s' into help string: " "could not find command handler for %r" % (marker, cmdname)) indent, indent_width = _get_indent(marker, help) suffix = _get_trailing_whitespace(marker, help) if hasattr(handler, "optparser"): # Setup formatting options and format. # - Indentation of 4 is better than optparse default of 2. # C.f. Damian Conway's discussion of this in Perl Best # Practices. handler.optparser.formatter.indent_increment = 4 handler.optparser.formatter.current_indent = indent_width block = handler.optparser.format_option_help() + '\n' else: block = "" help = help.replace(indent+marker+suffix, block, 1) return help def _get_canonical_cmd_name(self, token): map = self._get_canonical_map() return map.get(token, None) def _get_canonical_map(self): """Return a mapping of available command names and aliases to their canonical command name. """ cacheattr = "_token2canonical" if not hasattr(self, cacheattr): # Get the list of commands and their aliases, if any. token2canonical = {} cmd2funcname = {} # use a dict to strip duplicates for attr in self.get_names(): if attr.startswith("do_"): cmdname = attr[3:] elif attr.startswith("_do_"): cmdname = attr[4:] else: continue cmd2funcname[cmdname] = attr token2canonical[cmdname] = cmdname for cmdname, funcname in cmd2funcname.items(): # add aliases func = getattr(self, funcname) aliases = getattr(func, "aliases", []) for alias in aliases: if alias in cmd2funcname: import warnings warnings.warn("'%s' alias for '%s' command conflicts " "with '%s' handler" % (alias, cmdname, cmd2funcname[alias])) continue token2canonical[alias] = cmdname setattr(self, cacheattr, token2canonical) return getattr(self, cacheattr) def _get_cmd_handler(self, cmdname): handler = None try: handler = getattr(self, 'do_' + cmdname) except AttributeError: try: # Private command handlers begin with "_do_". handler = getattr(self, '_do_' + cmdname) except AttributeError: pass return handler def _do_EOF(self, argv): # Default EOF handler # Note: an actual EOF is redirected to this command. #TODO: separate name for this. Currently it is available from # command-line. Is that okay? self.stdout.write('\n') self.stdout.flush() self.stop = True def emptyline(self): # Different from cmd.Cmd: don't repeat the last command for an # emptyline. if self.cmdlooping: pass else: return self.do_help(["help"]) #---- optparse.py extension to fix (IMO) some deficiencies # # See the class _OptionParserEx docstring for details. # class StopOptionProcessing(Exception): """Indicate that option *and argument* processing should stop cleanly. This is not an error condition. It is similar in spirit to StopIteration. This is raised by _OptionParserEx's default "help" and "version" option actions and can be raised by custom option callbacks too. Hence the typical CmdlnOptionParser (a subclass of _OptionParserEx) usage is: parser = CmdlnOptionParser(mycmd) parser.add_option("-f", "--force", dest="force") ... try: opts, args = parser.parse_args() except StopOptionProcessing: # normal termination, "--help" was probably given sys.exit(0) """ class _OptionParserEx(optparse.OptionParser): """An optparse.OptionParser that uses exceptions instead of sys.exit. This class is an extension of optparse.OptionParser that differs as follows: - Correct (IMO) the default OptionParser error handling to never sys.exit(). Instead OptParseError exceptions are passed through. - Add the StopOptionProcessing exception (a la StopIteration) to indicate normal termination of option processing. See StopOptionProcessing's docstring for details. I'd also like to see the following in the core optparse.py, perhaps as a RawOptionParser which would serve as a base class for the more generally used OptionParser (that works as current): - Remove the implicit addition of the -h|--help and --version options. They can get in the way (e.g. if want '-?' and '-V' for these as well) and it is not hard to do: optparser.add_option("-h", "--help", action="help") optparser.add_option("--version", action="version") These are good practices, just not valid defaults if they can get in the way. """ def error(self, msg): raise optparse.OptParseError(msg) def exit(self, status=0, msg=None): if status == 0: raise StopOptionProcessing(msg) else: #TODO: don't lose status info here raise optparse.OptParseError(msg) #---- optparse.py-based option processing support class CmdlnOptionParser(_OptionParserEx): """An optparse.OptionParser class more appropriate for top-level Cmdln options. For parsing of sub-command options, see SubCmdOptionParser. Changes: - disable_interspersed_args() by default, because a Cmdln instance has sub-commands which may themselves have options. - Redirect print_help() to the Cmdln.do_help() which is better equiped to handle the "help" action. - error() will raise a CmdlnUserError: OptionParse.error() is meant to be called for user errors. Raising a well-known error here can make error handling clearer. - Also see the changes in _OptionParserEx. """ def __init__(self, cmdln, **kwargs): self.cmdln = cmdln kwargs["prog"] = self.cmdln.name _OptionParserEx.__init__(self, **kwargs) self.disable_interspersed_args() def print_help(self, file=None): self.cmdln.onecmd(["help"]) def error(self, msg): raise CmdlnUserError(msg) class SubCmdOptionParser(_OptionParserEx): def set_cmdln_info(self, cmdln, subcmd): """Called by Cmdln to pass relevant info about itself needed for print_help(). """ self.cmdln = cmdln self.subcmd = subcmd def print_help(self, file=None): self.cmdln.onecmd(["help", self.subcmd]) def error(self, msg): raise CmdlnUserError(msg) def option(*args, **kwargs): """Decorator to add an option to the optparser argument of a Cmdln subcommand. Example: class MyShell(cmdln.Cmdln): @cmdln.option("-f", "--force", help="force removal") def do_remove(self, subcmd, opts, *args): #... """ #XXX Is there a possible optimization for many options to not have a # large stack depth here? def decorate(f): if not hasattr(f, "optparser"): f.optparser = SubCmdOptionParser() f.optparser.add_option(*args, **kwargs) return f return decorate def hide(*args): """For obsolete calls, hide them in help listings. Example: class MyShell(cmdln.Cmdln): @cmdln.hide() def do_shell(self, argv): #...implement 'shell' command """ def decorate(f): f.hidden = 1 return f return decorate class Cmdln(RawCmdln): """An improved (on cmd.Cmd) framework for building multi-subcommand scripts (think "svn" & "cvs") and simple shells (think "pdb" and "gdb"). A simple example: import cmdln class MySVN(cmdln.Cmdln): name = "svn" @cmdln.aliases('stat', 'st') @cmdln.option('-v', '--verbose', action='store_true' help='print verbose information') def do_status(self, subcmd, opts, *paths): print "handle 'svn status' command" #... if __name__ == "__main__": shell = MySVN() retval = shell.main() sys.exit(retval) 'Cmdln' extends 'RawCmdln' by providing optparse option processing integration. See this class' _dispatch_cmd() docstring and for more information. """ def _dispatch_cmd(self, handler, argv): """Introspect sub-command handler signature to determine how to dispatch the command. The raw handler provided by the base 'RawCmdln' class is still supported: def do_foo(self, argv): # 'argv' is the vector of command line args, argv[0] is # the command name itself (i.e. "foo" or an alias) pass In addition, if the handler has more than 2 arguments option processing is automatically done (using optparse): @cmdln.option('-v', '--verbose', action='store_true') def do_bar(self, subcmd, opts, *args): # subcmd = <"bar" or an alias> # opts = if opts.verbose: print "lots of debugging output..." # args = for arg in args: bar(arg) TODO: explain that "*args" can be other signatures as well. The `cmdln.option` decorator corresponds to an `add_option()` method call on an `optparse.OptionParser` instance. You can declare a specific number of arguments: @cmdln.option('-v', '--verbose', action='store_true') def do_bar2(self, subcmd, opts, bar_one, bar_two): #... and an appropriate error message will be raised/printed if the command is called with a different number of args. """ co_argcount = handler.im_func.func_code.co_argcount if co_argcount == 2: # handler ::= do_foo(self, argv) return handler(argv) elif co_argcount >= 3: # handler ::= do_foo(self, subcmd, opts, ...) try: optparser = handler.optparser except AttributeError: optparser = handler.im_func.optparser = SubCmdOptionParser() assert isinstance(optparser, SubCmdOptionParser) optparser.set_cmdln_info(self, argv[0]) try: opts, args = optparser.parse_args(argv[1:]) except StopOptionProcessing: #TODO: this doesn't really fly for a replacement of # optparse.py behaviour, does it? return 0 # Normal command termination try: return handler(argv[0], opts, *args) except TypeError, ex: # Some TypeError's are user errors: # do_foo() takes at least 4 arguments (3 given) # do_foo() takes at most 5 arguments (6 given) # do_foo() takes exactly 5 arguments (6 given) # Raise CmdlnUserError for these with a suitably # massaged error message. import sys tb = sys.exc_info()[2] # the traceback object if tb.tb_next is not None: # If the traceback is more than one level deep, then the # TypeError do *not* happen on the "handler(...)" call # above. In that we don't want to handle it specially # here: it would falsely mask deeper code errors. raise msg = ex.args[0] match = _INCORRECT_NUM_ARGS_RE.search(msg) if match: msg = list(match.groups()) msg[1] = int(msg[1]) - 3 if msg[1] == 1: msg[2] = msg[2].replace("arguments", "argument") msg[3] = int(msg[3]) - 3 msg = ''.join(map(str, msg)) raise CmdlnUserError(msg) else: raise else: raise CmdlnError("incorrect argcount for %s(): takes %d, must " "take 2 for 'argv' signature or 3+ for 'opts' " "signature" % (handler.__name__, co_argcount)) #---- internal support functions def _format_linedata(linedata, indent, indent_width): """Format specific linedata into a pleasant layout. "linedata" is a list of 2-tuples of the form: (, ) "indent" is a string to use for one level of indentation "indent_width" is a number of columns by which the formatted data will be indented when printed. The column is held to 15 columns. """ lines = [] WIDTH = 78 - indent_width SPACING = 3 MAX_NAME_WIDTH = 15 NAME_WIDTH = min(max([len(s) for s,d in linedata]), MAX_NAME_WIDTH) DOC_WIDTH = WIDTH - NAME_WIDTH - SPACING for namestr, doc in linedata: line = indent + namestr if len(namestr) <= NAME_WIDTH: line += ' ' * (NAME_WIDTH + SPACING - len(namestr)) else: lines.append(line) line = indent + ' ' * (NAME_WIDTH + SPACING) line += _summarize_doc(doc, DOC_WIDTH) lines.append(line.rstrip()) return lines def _summarize_doc(doc, length=60): r"""Parse out a short one line summary from the given doclines. "doc" is the doc string to summarize. "length" is the max length for the summary >>> _summarize_doc("this function does this") 'this function does this' >>> _summarize_doc("this function does this", 10) 'this fu...' >>> _summarize_doc("this function does this\nand that") 'this function does this and that' >>> _summarize_doc("this function does this\n\nand that") 'this function does this' """ import re if doc is None: return "" assert length > 3, "length <= 3 is absurdly short for a doc summary" doclines = doc.strip().splitlines(0) if not doclines: return "" summlines = [] for i, line in enumerate(doclines): stripped = line.strip() if not stripped: break summlines.append(stripped) if len(''.join(summlines)) >= length: break summary = ' '.join(summlines) if len(summary) > length: summary = summary[:length-3] + "..." return summary def line2argv(line): r"""Parse the given line into an argument vector. "line" is the line of input to parse. This may get niggly when dealing with quoting and escaping. The current state of this parsing may not be completely thorough/correct in this respect. >>> from cmdln import line2argv >>> line2argv("foo") ['foo'] >>> line2argv("foo bar") ['foo', 'bar'] >>> line2argv("foo bar ") ['foo', 'bar'] >>> line2argv(" foo bar") ['foo', 'bar'] Quote handling: >>> line2argv("'foo bar'") ['foo bar'] >>> line2argv('"foo bar"') ['foo bar'] >>> line2argv(r'"foo\"bar"') ['foo"bar'] >>> line2argv("'foo bar' spam") ['foo bar', 'spam'] >>> line2argv("'foo 'bar spam") ['foo bar', 'spam'] >>> line2argv("'foo") Traceback (most recent call last): ... ValueError: command line is not terminated: unfinished single-quoted segment >>> line2argv('"foo') Traceback (most recent call last): ... ValueError: command line is not terminated: unfinished double-quoted segment >>> line2argv('some\tsimple\ttests') ['some', 'simple', 'tests'] >>> line2argv('a "more complex" test') ['a', 'more complex', 'test'] >>> line2argv('a more="complex test of " quotes') ['a', 'more=complex test of ', 'quotes'] >>> line2argv('a more" complex test of " quotes') ['a', 'more complex test of ', 'quotes'] >>> line2argv('an "embedded \\"quote\\""') ['an', 'embedded "quote"'] """ import string line = line.strip() argv = [] state = "default" arg = None # the current argument being parsed i = -1 while 1: i += 1 if i >= len(line): break ch = line[i] if ch == "\\": # escaped char always added to arg, regardless of state if arg is None: arg = "" i += 1 arg += line[i] continue if state == "single-quoted": if ch == "'": state = "default" else: arg += ch elif state == "double-quoted": if ch == '"': state = "default" else: arg += ch elif state == "default": if ch == '"': if arg is None: arg = "" state = "double-quoted" elif ch == "'": if arg is None: arg = "" state = "single-quoted" elif ch in string.whitespace: if arg is not None: argv.append(arg) arg = None else: if arg is None: arg = "" arg += ch if arg is not None: argv.append(arg) if state != "default": raise ValueError("command line is not terminated: unfinished %s " "segment" % state) return argv def argv2line(argv): r"""Put together the given argument vector into a command line. "argv" is the argument vector to process. >>> from cmdln import argv2line >>> argv2line(['foo']) 'foo' >>> argv2line(['foo', 'bar']) 'foo bar' >>> argv2line(['foo', 'bar baz']) 'foo "bar baz"' >>> argv2line(['foo"bar']) 'foo"bar' >>> print argv2line(['foo" bar']) 'foo" bar' >>> print argv2line(["foo' bar"]) "foo' bar" >>> argv2line(["foo'bar"]) "foo'bar" """ escapedArgs = [] for arg in argv: if ' ' in arg and '"' not in arg: arg = '"'+arg+'"' elif ' ' in arg and "'" not in arg: arg = "'"+arg+"'" elif ' ' in arg: arg = arg.replace('"', r'\"') arg = '"'+arg+'"' escapedArgs.append(arg) return ' '.join(escapedArgs) # Recipe: dedent (0.1) in /Users/trentm/tm/recipes/cookbook def _dedentlines(lines, tabsize=8, skip_first_line=False): """_dedentlines(lines, tabsize=8, skip_first_line=False) -> dedented lines "lines" is a list of lines to dedent. "tabsize" is the tab width to use for indent width calculations. "skip_first_line" is a boolean indicating if the first line should be skipped for calculating the indent width and for dedenting. This is sometimes useful for docstrings and similar. Same as dedent() except operates on a sequence of lines. Note: the lines list is modified **in-place**. """ DEBUG = False if DEBUG: print "dedent: dedent(..., tabsize=%d, skip_first_line=%r)"\ % (tabsize, skip_first_line) indents = [] margin = None for i, line in enumerate(lines): if i == 0 and skip_first_line: continue indent = 0 for ch in line: if ch == ' ': indent += 1 elif ch == '\t': indent += tabsize - (indent % tabsize) elif ch in '\r\n': continue # skip all-whitespace lines else: break else: continue # skip all-whitespace lines if DEBUG: print "dedent: indent=%d: %r" % (indent, line) if margin is None: margin = indent else: margin = min(margin, indent) if DEBUG: print "dedent: margin=%r" % margin if margin is not None and margin > 0: for i, line in enumerate(lines): if i == 0 and skip_first_line: continue removed = 0 for j, ch in enumerate(line): if ch == ' ': removed += 1 elif ch == '\t': removed += tabsize - (removed % tabsize) elif ch in '\r\n': if DEBUG: print "dedent: %r: EOL -> strip up to EOL" % line lines[i] = lines[i][j:] break else: raise ValueError("unexpected non-whitespace char %r in " "line %r while removing %d-space margin" % (ch, line, margin)) if DEBUG: print "dedent: %r: %r -> removed %d/%d"\ % (line, ch, removed, margin) if removed == margin: lines[i] = lines[i][j+1:] break elif removed > margin: lines[i] = ' '*(removed-margin) + lines[i][j+1:] break return lines def _dedent(text, tabsize=8, skip_first_line=False): """_dedent(text, tabsize=8, skip_first_line=False) -> dedented text "text" is the text to dedent. "tabsize" is the tab width to use for indent width calculations. "skip_first_line" is a boolean indicating if the first line should be skipped for calculating the indent width and for dedenting. This is sometimes useful for docstrings and similar. textwrap.dedent(s), but don't expand tabs to spaces """ lines = text.splitlines(1) _dedentlines(lines, tabsize=tabsize, skip_first_line=skip_first_line) return ''.join(lines) def _get_indent(marker, s, tab_width=8): """_get_indent(marker, s, tab_width=8) -> (, )""" # Figure out how much the marker is indented. INDENT_CHARS = tuple(' \t') start = s.index(marker) i = start while i > 0: if s[i-1] not in INDENT_CHARS: break i -= 1 indent = s[i:start] indent_width = 0 for ch in indent: if ch == ' ': indent_width += 1 elif ch == '\t': indent_width += tab_width - (indent_width % tab_width) return indent, indent_width def _get_trailing_whitespace(marker, s): """Return the whitespace content trailing the given 'marker' in string 's', up to and including a newline. """ suffix = '' start = s.index(marker) + len(marker) i = start while i < len(s): if s[i] in ' \t': suffix += s[i] elif s[i] in '\r\n': suffix += s[i] if s[i] == '\r' and i+1 < len(s) and s[i+1] == '\n': suffix += s[i+1] break else: break i += 1 return suffix