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git.proxmox.com Git - mirror_edk2.git/blob - AppPkg/Applications/Python/Python-2.7.10/Lib/cmd.py
1 """A generic class to build line-oriented command interpreters.
3 Interpreters constructed with this class obey the following conventions:
5 1. End of file on input is processed as the command 'EOF'.
6 2. A command is parsed out of each line by collecting the prefix composed
7 of characters in the identchars member.
8 3. 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.
10 4. Typing an empty line repeats the last command. (Actually, it calls the
11 method `emptyline', which may be overridden in a subclass.)
12 5. 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.
16 6. The command '?' is a synonym for `help'. The command '!' is a synonym
17 for `shell', if a do_shell method exists.
18 7. 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.
26 The `default' method may be overridden to intercept commands for which there
29 The `completedefault' method may be overridden to intercept completions for
30 commands that have no complete_ method.
32 The data member `self.ruler' sets the character used to draw separator lines
33 in the help messages. If empty, no ruler line is drawn. It defaults to "=".
35 If the value of `self.intro' is nonempty when the cmdloop method is called,
36 it is printed out on interpreter startup. This value may be overridden
37 via an optional argument to the cmdloop() method.
39 The data members `self.doc_header', `self.misc_header', and
40 `self.undoc_header' set the headers used for the help function's
41 listings of documented functions, miscellaneous topics, and undocumented
42 functions respectively.
44 These interpreters use raw_input; thus, if the readline module is loaded,
45 they automatically support Emacs-like command history and editing features.
53 IDENTCHARS
= string
.ascii_letters
+ string
.digits
+ '_'
56 """A simple framework for writing line-oriented command interpreters.
58 These are often useful for test harnesses, administrative tools, and
59 prototypes that will later be wrapped in a more sophisticated interface.
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.
68 identchars
= IDENTCHARS
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"
79 def __init__(self
, completekey
='tab', stdin
=None, stdout
=None):
80 """Instantiate a line-oriented interpreter framework.
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.
94 self
.stdin
= sys
.stdin
95 if stdout
is not None:
98 self
.stdout
= sys
.stdout
100 self
.completekey
= completekey
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.
110 if self
.use_rawinput
and self
.completekey
:
113 self
.old_completer
= readline
.get_completer()
114 readline
.set_completer(self
.complete
)
115 readline
.parse_and_bind(self
.completekey
+": complete")
119 if intro
is not None:
122 self
.stdout
.write(str(self
.intro
)+"\n")
126 line
= self
.cmdqueue
.pop(0)
128 if self
.use_rawinput
:
130 line
= raw_input(self
.prompt
)
134 self
.stdout
.write(self
.prompt
)
136 line
= self
.stdin
.readline()
140 line
= line
.rstrip('\r\n')
141 line
= self
.precmd(line
)
142 stop
= self
.onecmd(line
)
143 stop
= self
.postcmd(stop
, line
)
146 if self
.use_rawinput
and self
.completekey
:
149 readline
.set_completer(self
.old_completer
)
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.
161 def postcmd(self
, stop
, line
):
162 """Hook method executed just after a command dispatch is finished."""
166 """Hook method executed once when the cmdloop() method is called."""
170 """Hook method executed once when the cmdloop() method is about to
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.
183 return None, None, line
185 line
= 'help ' + line
[1:]
187 if hasattr(self
, 'do_shell'):
188 line
= 'shell ' + line
[1:]
190 return None, None, 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
196 def onecmd(self
, line
):
197 """Interpret the argument as though it had been typed in response
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.
206 cmd
, arg
, line
= self
.parseline(line
)
208 return self
.emptyline()
210 return self
.default(line
)
215 return self
.default(line
)
218 func
= getattr(self
, 'do_' + cmd
)
219 except AttributeError:
220 return self
.default(line
)
224 """Called when an empty line is entered in response to the prompt.
226 If this method is not overridden, it repeats the last nonempty
231 return self
.onecmd(self
.lastcmd
)
233 def default(self
, line
):
234 """Called on an input line when the command prefix is not recognized.
236 If this method is not overridden, it prints an error message and
240 self
.stdout
.write('*** Unknown syntax: %s\n'%line
)
242 def completedefault(self
, *ignored
):
243 """Method called to complete an input line when no command-specific
244 complete_*() method is available.
246 By default, it returns an empty list.
251 def completenames(self
, text
, *ignored
):
253 return [a
[3:] for a
in self
.get_names() if a
.startswith(dotext
)]
255 def complete(self
, text
, state
):
256 """Return the next possible completion for 'text'.
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.
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
269 cmd
, args
, foo
= self
.parseline(line
)
271 compfunc
= self
.completedefault
274 compfunc
= getattr(self
, 'complete_' + cmd
)
275 except AttributeError:
276 compfunc
= self
.completedefault
278 compfunc
= self
.completenames
279 self
.completion_matches
= compfunc(text
, line
, begidx
, endidx
)
281 return self
.completion_matches
[state
]
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
__)
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
)
296 def do_help(self
, arg
):
297 'List available commands with "help" or detailed help with "help cmd".'
299 # XXX check arg syntax
301 func
= getattr(self
, 'help_' + arg
)
302 except AttributeError:
304 doc
=getattr(self
, 'do_' + arg
).__doc
__
306 self
.stdout
.write("%s\n"%str
(doc
))
308 except AttributeError:
310 self
.stdout
.write("%s\n"%str
(self
.nohelp
% (arg
,)))
314 names
= self
.get_names()
319 if name
[:5] == 'help_':
322 # There can be duplicates if routines overridden
325 if name
[:3] == 'do_':
333 elif getattr(self
, name
).__doc
__:
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)
342 def print_topics(self
, header
, cmds
, cmdlen
, maxcol
):
344 self
.stdout
.write("%s\n"%str
(header
))
346 self
.stdout
.write("%s\n"%str
(self
.ruler
* len(header
)))
347 self
.columnize(cmds
, maxcol
-1)
348 self
.stdout
.write("\n")
350 def columnize(self
, list, displaywidth
=80):
351 """Display a list of strings as a compact set of columns.
353 Each column is only as wide as necessary.
354 Columns are separated by two spaces (one was not legible enough).
357 self
.stdout
.write("<empty>\n")
359 nonstrings
= [i
for i
in range(len(list))
360 if not isinstance(list[i
], str)]
362 raise TypeError, ("list[i] not a string for i in %s" %
363 ", ".join(map(str, nonstrings
)))
366 self
.stdout
.write('%s\n'%str
(list[0]))
368 # Try every row count from 1 upwards
369 for nrows
in range(1, len(list)):
370 ncols
= (size
+nrows
-1) // nrows
373 for col
in range(ncols
):
375 for row
in range(nrows
):
380 colwidth
= max(colwidth
, len(x
))
381 colwidths
.append(colwidth
)
382 totwidth
+= colwidth
+ 2
383 if totwidth
> displaywidth
:
385 if totwidth
<= displaywidth
:
391 for row
in range(nrows
):
393 for col
in range(ncols
):
400 while texts
and not 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
)))