source: titan/mediathek/localhoster/lib/python2.7/cmd.py @ 40114

Last change on this file since 40114 was 40094, checked in by obi, 5 years ago

tithek add yoztube-dl support

File size: 14.7 KB
Line 
1"""A generic class to build line-oriented command interpreters.
2
3Interpreters constructed with this class obey the following conventions:
4
51. End of file on input is processed as the command 'EOF'.
62. A command is parsed out of each line by collecting the prefix composed
7   of characters in the identchars member.
83. A command `foo' is dispatched to a method 'do_foo()'; the do_ method
9   is passed a single argument consisting of the remainder of the line.
104. Typing an empty line repeats the last command.  (Actually, it calls the
11   method `emptyline', which may be overridden in a subclass.)
125. There is a predefined `help' method.  Given an argument `topic', it
13   calls the command `help_topic'.  With no arguments, it lists all topics
14   with defined help_ functions, broken into up to three topics; documented
15   commands, miscellaneous help topics, and undocumented commands.
166. The command '?' is a synonym for `help'.  The command '!' is a synonym
17   for `shell', if a do_shell method exists.
187. If completion is enabled, completing commands will be done automatically,
19   and completing of commands args is done by calling complete_foo() with
20   arguments text, line, begidx, endidx.  text is string we are matching
21   against, all returned matches must begin with it.  line is the current
22   input line (lstripped), begidx and endidx are the beginning and end
23   indexes of the text being matched, which could be used to provide
24   different completion depending upon which position the argument is in.
25
26The `default' method may be overridden to intercept commands for which there
27is no do_ method.
28
29The `completedefault' method may be overridden to intercept completions for
30commands that have no complete_ method.
31
32The data member `self.ruler' sets the character used to draw separator lines
33in the help messages.  If empty, no ruler line is drawn.  It defaults to "=".
34
35If the value of `self.intro' is nonempty when the cmdloop method is called,
36it is printed out on interpreter startup.  This value may be overridden
37via an optional argument to the cmdloop() method.
38
39The data members `self.doc_header', `self.misc_header', and
40`self.undoc_header' set the headers used for the help function's
41listings of documented functions, miscellaneous topics, and undocumented
42functions respectively.
43
44These interpreters use raw_input; thus, if the readline module is loaded,
45they automatically support Emacs-like command history and editing features.
46"""
47
48import string
49
50__all__ = ["Cmd"]
51
52PROMPT = '(Cmd) '
53IDENTCHARS = string.ascii_letters + string.digits + '_'
54
55class Cmd:
56    """A simple framework for writing line-oriented command interpreters.
57
58    These are often useful for test harnesses, administrative tools, and
59    prototypes that will later be wrapped in a more sophisticated interface.
60
61    A Cmd instance or subclass instance is a line-oriented interpreter
62    framework.  There is no good reason to instantiate Cmd itself; rather,
63    it's useful as a superclass of an interpreter class you define yourself
64    in order to inherit Cmd's methods and encapsulate action methods.
65
66    """
67    prompt = PROMPT
68    identchars = IDENTCHARS
69    ruler = '='
70    lastcmd = ''
71    intro = None
72    doc_leader = ""
73    doc_header = "Documented commands (type help <topic>):"
74    misc_header = "Miscellaneous help topics:"
75    undoc_header = "Undocumented commands:"
76    nohelp = "*** No help on %s"
77    use_rawinput = 1
78
79    def __init__(self, completekey='tab', stdin=None, stdout=None):
80        """Instantiate a line-oriented interpreter framework.
81
82        The optional argument 'completekey' is the readline name of a
83        completion key; it defaults to the Tab key. If completekey is
84        not None and the readline module is available, command completion
85        is done automatically. The optional arguments stdin and stdout
86        specify alternate input and output file objects; if not specified,
87        sys.stdin and sys.stdout are used.
88
89        """
90        import sys
91        if stdin is not None:
92            self.stdin = stdin
93        else:
94            self.stdin = sys.stdin
95        if stdout is not None:
96            self.stdout = stdout
97        else:
98            self.stdout = sys.stdout
99        self.cmdqueue = []
100        self.completekey = completekey
101
102    def cmdloop(self, intro=None):
103        """Repeatedly issue a prompt, accept input, parse an initial prefix
104        off the received input, and dispatch to action methods, passing them
105        the remainder of the line as argument.
106
107        """
108
109        self.preloop()
110        if self.use_rawinput and self.completekey:
111            try:
112                import readline
113                self.old_completer = readline.get_completer()
114                readline.set_completer(self.complete)
115                readline.parse_and_bind(self.completekey+": complete")
116            except ImportError:
117                pass
118        try:
119            if intro is not None:
120                self.intro = intro
121            if self.intro:
122                self.stdout.write(str(self.intro)+"\n")
123            stop = None
124            while not stop:
125                if self.cmdqueue:
126                    line = self.cmdqueue.pop(0)
127                else:
128                    if self.use_rawinput:
129                        try:
130                            line = raw_input(self.prompt)
131                        except EOFError:
132                            line = 'EOF'
133                    else:
134                        self.stdout.write(self.prompt)
135                        self.stdout.flush()
136                        line = self.stdin.readline()
137                        if not len(line):
138                            line = 'EOF'
139                        else:
140                            line = line.rstrip('\r\n')
141                line = self.precmd(line)
142                stop = self.onecmd(line)
143                stop = self.postcmd(stop, line)
144            self.postloop()
145        finally:
146            if self.use_rawinput and self.completekey:
147                try:
148                    import readline
149                    readline.set_completer(self.old_completer)
150                except ImportError:
151                    pass
152
153
154    def precmd(self, line):
155        """Hook method executed just before the command line is
156        interpreted, but after the input prompt is generated and issued.
157
158        """
159        return line
160
161    def postcmd(self, stop, line):
162        """Hook method executed just after a command dispatch is finished."""
163        return stop
164
165    def preloop(self):
166        """Hook method executed once when the cmdloop() method is called."""
167        pass
168
169    def postloop(self):
170        """Hook method executed once when the cmdloop() method is about to
171        return.
172
173        """
174        pass
175
176    def parseline(self, line):
177        """Parse the line into a command name and a string containing
178        the arguments.  Returns a tuple containing (command, args, line).
179        'command' and 'args' may be None if the line couldn't be parsed.
180        """
181        line = line.strip()
182        if not line:
183            return None, None, line
184        elif line[0] == '?':
185            line = 'help ' + line[1:]
186        elif line[0] == '!':
187            if hasattr(self, 'do_shell'):
188                line = 'shell ' + line[1:]
189            else:
190                return None, None, line
191        i, n = 0, len(line)
192        while i < n and line[i] in self.identchars: i = i+1
193        cmd, arg = line[:i], line[i:].strip()
194        return cmd, arg, line
195
196    def onecmd(self, line):
197        """Interpret the argument as though it had been typed in response
198        to the prompt.
199
200        This may be overridden, but should not normally need to be;
201        see the precmd() and postcmd() methods for useful execution hooks.
202        The return value is a flag indicating whether interpretation of
203        commands by the interpreter should stop.
204
205        """
206        cmd, arg, line = self.parseline(line)
207        if not line:
208            return self.emptyline()
209        if cmd is None:
210            return self.default(line)
211        self.lastcmd = line
212        if line == 'EOF' :
213            self.lastcmd = ''
214        if cmd == '':
215            return self.default(line)
216        else:
217            try:
218                func = getattr(self, 'do_' + cmd)
219            except AttributeError:
220                return self.default(line)
221            return func(arg)
222
223    def emptyline(self):
224        """Called when an empty line is entered in response to the prompt.
225
226        If this method is not overridden, it repeats the last nonempty
227        command entered.
228
229        """
230        if self.lastcmd:
231            return self.onecmd(self.lastcmd)
232
233    def default(self, line):
234        """Called on an input line when the command prefix is not recognized.
235
236        If this method is not overridden, it prints an error message and
237        returns.
238
239        """
240        self.stdout.write('*** Unknown syntax: %s\n'%line)
241
242    def completedefault(self, *ignored):
243        """Method called to complete an input line when no command-specific
244        complete_*() method is available.
245
246        By default, it returns an empty list.
247
248        """
249        return []
250
251    def completenames(self, text, *ignored):
252        dotext = 'do_'+text
253        return [a[3:] for a in self.get_names() if a.startswith(dotext)]
254
255    def complete(self, text, state):
256        """Return the next possible completion for 'text'.
257
258        If a command has not been entered, then complete against command list.
259        Otherwise try to call complete_<command> to get list of completions.
260        """
261        if state == 0:
262            import readline
263            origline = readline.get_line_buffer()
264            line = origline.lstrip()
265            stripped = len(origline) - len(line)
266            begidx = readline.get_begidx() - stripped
267            endidx = readline.get_endidx() - stripped
268            if begidx>0:
269                cmd, args, foo = self.parseline(line)
270                if cmd == '':
271                    compfunc = self.completedefault
272                else:
273                    try:
274                        compfunc = getattr(self, 'complete_' + cmd)
275                    except AttributeError:
276                        compfunc = self.completedefault
277            else:
278                compfunc = self.completenames
279            self.completion_matches = compfunc(text, line, begidx, endidx)
280        try:
281            return self.completion_matches[state]
282        except IndexError:
283            return None
284
285    def get_names(self):
286        # This method used to pull in base class attributes
287        # at a time dir() didn't do it yet.
288        return dir(self.__class__)
289
290    def complete_help(self, *args):
291        commands = set(self.completenames(*args))
292        topics = set(a[5:] for a in self.get_names()
293                     if a.startswith('help_' + args[0]))
294        return list(commands | topics)
295
296    def do_help(self, arg):
297        'List available commands with "help" or detailed help with "help cmd".'
298        if arg:
299            # XXX check arg syntax
300            try:
301                func = getattr(self, 'help_' + arg)
302            except AttributeError:
303                try:
304                    doc=getattr(self, 'do_' + arg).__doc__
305                    if doc:
306                        self.stdout.write("%s\n"%str(doc))
307                        return
308                except AttributeError:
309                    pass
310                self.stdout.write("%s\n"%str(self.nohelp % (arg,)))
311                return
312            func()
313        else:
314            names = self.get_names()
315            cmds_doc = []
316            cmds_undoc = []
317            help = {}
318            for name in names:
319                if name[:5] == 'help_':
320                    help[name[5:]]=1
321            names.sort()
322            # There can be duplicates if routines overridden
323            prevname = ''
324            for name in names:
325                if name[:3] == 'do_':
326                    if name == prevname:
327                        continue
328                    prevname = name
329                    cmd=name[3:]
330                    if cmd in help:
331                        cmds_doc.append(cmd)
332                        del help[cmd]
333                    elif getattr(self, name).__doc__:
334                        cmds_doc.append(cmd)
335                    else:
336                        cmds_undoc.append(cmd)
337            self.stdout.write("%s\n"%str(self.doc_leader))
338            self.print_topics(self.doc_header,   cmds_doc,   15,80)
339            self.print_topics(self.misc_header,  help.keys(),15,80)
340            self.print_topics(self.undoc_header, cmds_undoc, 15,80)
341
342    def print_topics(self, header, cmds, cmdlen, maxcol):
343        if cmds:
344            self.stdout.write("%s\n"%str(header))
345            if self.ruler:
346                self.stdout.write("%s\n"%str(self.ruler * len(header)))
347            self.columnize(cmds, maxcol-1)
348            self.stdout.write("\n")
349
350    def columnize(self, list, displaywidth=80):
351        """Display a list of strings as a compact set of columns.
352
353        Each column is only as wide as necessary.
354        Columns are separated by two spaces (one was not legible enough).
355        """
356        if not list:
357            self.stdout.write("<empty>\n")
358            return
359        nonstrings = [i for i in range(len(list))
360                        if not isinstance(list[i], str)]
361        if nonstrings:
362            raise TypeError, ("list[i] not a string for i in %s" %
363                              ", ".join(map(str, nonstrings)))
364        size = len(list)
365        if size == 1:
366            self.stdout.write('%s\n'%str(list[0]))
367            return
368        # Try every row count from 1 upwards
369        for nrows in range(1, len(list)):
370            ncols = (size+nrows-1) // nrows
371            colwidths = []
372            totwidth = -2
373            for col in range(ncols):
374                colwidth = 0
375                for row in range(nrows):
376                    i = row + nrows*col
377                    if i >= size:
378                        break
379                    x = list[i]
380                    colwidth = max(colwidth, len(x))
381                colwidths.append(colwidth)
382                totwidth += colwidth + 2
383                if totwidth > displaywidth:
384                    break
385            if totwidth <= displaywidth:
386                break
387        else:
388            nrows = len(list)
389            ncols = 1
390            colwidths = [0]
391        for row in range(nrows):
392            texts = []
393            for col in range(ncols):
394                i = row + nrows*col
395                if i >= size:
396                    x = ""
397                else:
398                    x = list[i]
399                texts.append(x)
400            while texts and not texts[-1]:
401                del texts[-1]
402            for col in range(len(texts)):
403                texts[col] = texts[col].ljust(colwidths[col])
404            self.stdout.write("%s\n"%str("  ".join(texts)))
Note: See TracBrowser for help on using the repository browser.