Module cmd :: Class Cmd

Class Cmd

Known Subclasses:

pdb.Pdb

A simple framework for writing line-oriented command interpreters.

These are often useful for test harnesses, administrative tools, and prototypes that will later be wrapped in a more sophisticated interface.

A Cmd instance or subclass instance is a line-oriented interpreter framework. There is no good reason to instantiate Cmd itself; rather, it's useful as a superclass of an interpreter class you define yourself in order to inherit Cmd's methods and encapsulate action methods.

Instance Methods

[hide private]

__init__(self, completekey='tab', stdin=None, stdout=None)
Instantiate a line-oriented interpreter framework.

cmdloop(self, intro=None)
Repeatedly issue a prompt, accept input, parse an initial prefix off the received input, and dispatch to action methods, passing them the remainder of the line as argument.

precmd(self, line)
Hook method executed just before the command line is interpreted, but after the input prompt is generated and issued.

postcmd(self, stop, line)
Hook method executed just after a command dispatch is finished.

preloop(self)
Hook method executed once when the cmdloop() method is called.

postloop(self)
Hook method executed once when the cmdloop() method is about to return.

parseline(self, line)
Parse the line into a command name and a string containing the arguments.

onecmd(self, line)
Interpret the argument as though it had been typed in response to the prompt.

emptyline(self)
Called when an empty line is entered in response to the prompt.

default(self, line)
Called on an input line when the command prefix is not recognized.

completedefault(self, *ignored)
Method called to complete an input line when no command-specific complete_*() method is available.

completenames(self, text, *ignored)

complete(self, text, state)
Return the next possible completion for 'text'.

get_names(self)

complete_help(self, *args)

do_help(self, arg)

print_topics(self, header, cmds, cmdlen, maxcol)

columnize(self, list, displaywidth=80)
Display a list of strings as a compact set of columns.

Class Variables

[hide private]

prompt = '(Cmd) '

identchars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUV...

ruler = '='

lastcmd = ''

intro = None

doc_leader = ''

doc_header = 'Documented commands (type help <topic>):'

misc_header = 'Miscellaneous help topics:'

undoc_header = 'Undocumented commands:'

nohelp = '*** No help on %s'

use_rawinput = 1

Method Details

[hide private]

init(self, completekey=`'tab'`, stdin=None, stdout=None)
(Constructor)

Instantiate a line-oriented interpreter framework.

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 and stdout specify alternate input and output file objects; if not specified, sys.stdin and sys.stdout are used.

parseline(self, line)

Parse the line into a command name and a string containing the arguments. Returns a tuple containing (command, args, line). 'command' and 'args' may be None if the line couldn't be parsed.

onecmd(self, line)

Interpret the argument as though it had been typed in response to the prompt.

This may be overridden, but should not normally need to be; see the precmd() and postcmd() methods for useful execution hooks. The return value is a flag indicating whether interpretation of commands by the interpreter should stop.

emptyline(self)

Called when an empty line is entered in response to the prompt.

If this method is not overridden, it repeats the last nonempty command entered.

default(self, line)

Called on an input line when the command prefix is not recognized.

If this method is not overridden, it prints an error message and returns.

completedefault(self, *ignored)

Method called to complete an input line when no command-specific complete_*() method is available.

By default, it returns an empty list.

complete(self, text, state)

Return the next possible completion for 'text'.

If a command has not been entered, then complete against command list. Otherwise try to call complete_<command> to get list of completions.

columnize(self, list, displaywidth=80)

Display a list of strings as a compact set of columns.

Each column is only as wide as necessary. Columns are separated by two spaces (one was not legible enough).

Class Variable Details

[hide private]

identchars

Value:

'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_'

Class Cmd

__init__(self, completekey='tab', stdin=None, stdout=None) (Constructor)

parseline(self, line)

onecmd(self, line)

emptyline(self)

default(self, line)

completedefault(self, *ignored)

complete(self, text, state)

columnize(self, list, displaywidth=80)

identchars

init(self, completekey=`'tab'`, stdin=None, stdout=None)
(Constructor)