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Guido van Rossumb53e6781992-01-24 01:12:17 +00001# A generic class to build line-oriented command interpreters
Guido van Rossum80884071998-06-29 17:58:55 +00002#
3# Interpreters constructed with this class obey the following conventions:
4#
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#
19# The `default' method may be overridden to intercept commands for which there
20# is no do_ method.
21#
22# The data member `self.ruler' sets the character used to draw separator lines
23# in the help messages. If empty, no ruler line is drawn. It defaults to "=".
24#
25# If the value of `self.intro' is nonempty when the cmdloop method is called,
26# it is printed out on interpreter startup. This value may be overridden
27# via an optional argument to the cmdloop() method.
28#
29# The data members `self.doc_header', `self.misc_header', and
30# `self.undoc_header' set the headers used for the help function's
31# listings of documented functions, miscellaneous topics, and undocumented
32# functions respectively.
33#
34# These interpreters use raw_input; thus, if the readline module is loaded,
35# they automatically support Emacs-like command history and editing features.
36#
Guido van Rossumb53e6781992-01-24 01:12:17 +000037
38import string
39import sys
40import linecache
41
42PROMPT = '(Cmd) '
43IDENTCHARS = string.letters + string.digits + '_'
44
45class Cmd:
Guido van Rossum80884071998-06-29 17:58:55 +000046 prompt = PROMPT
47 identchars = IDENTCHARS
48 ruler = '='
49 lastcmd = ''
Guido van Rossumb9f48601998-08-27 19:02:51 +000050 cmdqueue = []
Guido van Rossum80884071998-06-29 17:58:55 +000051 intro = None
Guido van Rossumb9f48601998-08-27 19:02:51 +000052 doc_leader = ""
Guido van Rossum80884071998-06-29 17:58:55 +000053 doc_header = "Documented commands (type help <topic>):"
54 misc_header = "Miscellaneous help topics:"
55 undoc_header = "Undocumented commands:"
Guido van Rossumb9f48601998-08-27 19:02:51 +000056 nohelp = "*** No help on %s"
Guido van Rossum9b3bc711993-06-20 21:02:22 +000057
Guido van Rossum030eb111998-07-01 22:53:04 +000058 def __init__(self): pass
59
Guido van Rossum80884071998-06-29 17:58:55 +000060 def cmdloop(self, intro=None):
61 self.preloop()
62 if intro != None:
63 self.intro = intro
64 if self.intro:
65 print self.intro
Guido van Rossumb53e6781992-01-24 01:12:17 +000066 stop = None
67 while not stop:
Guido van Rossumb9f48601998-08-27 19:02:51 +000068 if self.cmdqueue:
69 line = self.cmdqueue[0]
70 del self.cmdqueue[0]
71 else:
72 try:
73 line = raw_input(self.prompt)
74 except EOFError:
75 line = 'EOF'
76 line = self.precmd(line)
Guido van Rossumb53e6781992-01-24 01:12:17 +000077 stop = self.onecmd(line)
Guido van Rossumb9f48601998-08-27 19:02:51 +000078 stop = self.postcmd(stop, line)
Guido van Rossum80884071998-06-29 17:58:55 +000079 self.postloop()
80
Guido van Rossumb9f48601998-08-27 19:02:51 +000081 def precmd(self, line):
82 return line
Guido van Rossum80884071998-06-29 17:58:55 +000083
Guido van Rossumb9f48601998-08-27 19:02:51 +000084 def postcmd(self, stop, line):
85 return stop
Guido van Rossum80884071998-06-29 17:58:55 +000086
87 def preloop(self):
88 pass
89
90 def postloop(self):
91 pass
Guido van Rossumb53e6781992-01-24 01:12:17 +000092
93 def onecmd(self, line):
94 line = string.strip(line)
Guido van Rossum80884071998-06-29 17:58:55 +000095 if line == '?':
96 line = 'help'
97 elif line == '!':
98 if hasattr(self, 'do_shell'):
99 line = 'shell'
100 else:
Guido van Rossumc6126811998-07-20 21:22:08 +0000101 return self.default(line)
Guido van Rossum80884071998-06-29 17:58:55 +0000102 elif not line:
Guido van Rossumc6126811998-07-20 21:22:08 +0000103 return self.emptyline()
Guido van Rossum80884071998-06-29 17:58:55 +0000104 self.lastcmd = line
Guido van Rossumb53e6781992-01-24 01:12:17 +0000105 i, n = 0, len(line)
106 while i < n and line[i] in self.identchars: i = i+1
107 cmd, arg = line[:i], string.strip(line[i:])
108 if cmd == '':
109 return self.default(line)
110 else:
111 try:
Guido van Rossumc629d341992-11-05 10:43:02 +0000112 func = getattr(self, 'do_' + cmd)
Guido van Rossumb53e6781992-01-24 01:12:17 +0000113 except AttributeError:
114 return self.default(line)
115 return func(arg)
116
Guido van Rossum80884071998-06-29 17:58:55 +0000117 def emptyline(self):
Guido van Rossumb9f48601998-08-27 19:02:51 +0000118 if self.lastcmd:
119 return self.onecmd(self.lastcmd)
Guido van Rossum80884071998-06-29 17:58:55 +0000120
Guido van Rossumb53e6781992-01-24 01:12:17 +0000121 def default(self, line):
122 print '*** Unknown syntax:', line
123
124 def do_help(self, arg):
125 if arg:
126 # XXX check arg syntax
127 try:
Guido van Rossumc629d341992-11-05 10:43:02 +0000128 func = getattr(self, 'help_' + arg)
Guido van Rossumb53e6781992-01-24 01:12:17 +0000129 except:
Guido van Rossumb9f48601998-08-27 19:02:51 +0000130 print self.nohelp % (arg,)
Guido van Rossumb53e6781992-01-24 01:12:17 +0000131 return
132 func()
133 else:
Guido van Rossum5fca6fd1998-09-11 22:33:08 +0000134 # Inheritance says we have to look in class and
135 # base classes; order is not important.
136 names = []
137 classes = [self.__class__]
138 while classes:
139 aclass = classes[0]
140 if aclass.__bases__:
141 classes = classes + list(aclass.__bases__)
142 names = names + dir(aclass)
143 del classes[0]
Guido van Rossumb6775db1994-08-01 11:34:53 +0000144 cmds_doc = []
145 cmds_undoc = []
146 help = {}
147 for name in names:
148 if name[:5] == 'help_':
149 help[name[5:]]=1
Guido van Rossum5fca6fd1998-09-11 22:33:08 +0000150 names.sort()
151 # There can be duplicates if routines overridden
152 prevname = ''
Guido van Rossumb53e6781992-01-24 01:12:17 +0000153 for name in names:
154 if name[:3] == 'do_':
Guido van Rossum5fca6fd1998-09-11 22:33:08 +0000155 if name == prevname:
156 continue
157 prevname = name
Guido van Rossumb6775db1994-08-01 11:34:53 +0000158 cmd=name[3:]
159 if help.has_key(cmd):
160 cmds_doc.append(cmd)
161 del help[cmd]
162 else:
163 cmds_undoc.append(cmd)
Guido van Rossumb9f48601998-08-27 19:02:51 +0000164 print self.doc_leader
Guido van Rossum80884071998-06-29 17:58:55 +0000165 self.print_topics(self.doc_header, cmds_doc, 15,80)
166 self.print_topics(self.misc_header, help.keys(),15,80)
167 self.print_topics(self.undoc_header, cmds_undoc, 15,80)
Guido van Rossumb6775db1994-08-01 11:34:53 +0000168
169 def print_topics(self, header, cmds, cmdlen, maxcol):
170 if cmds:
171 print header;
Guido van Rossum80884071998-06-29 17:58:55 +0000172 if self.ruler:
173 print self.ruler * len(header)
Guido van Rossumb6775db1994-08-01 11:34:53 +0000174 (cmds_per_line,junk)=divmod(maxcol,cmdlen)
175 col=cmds_per_line
176 for cmd in cmds:
177 if col==0: print
178 print (("%-"+`cmdlen`+"s") % cmd),
179 col = (col+1) % cmds_per_line
180 print "\n"