|
428
|
1
|
|
|
2 @node M-x, Help, Minibuffer, Top
|
|
|
3 @chapter Running Commands by Name
|
|
|
4
|
|
|
5 The Emacs commands that are used often or that must be quick to type are
|
|
|
6 bound to keys---short sequences of characters---for convenient use. Other
|
|
|
7 Emacs commands that are used more rarely are not bound to keys; to run
|
|
|
8 them, you must refer to them by name.
|
|
|
9
|
|
|
10 A command name consists, by convention, of one or more words,
|
|
|
11 separated by hyphens: for example, @code{auto-fill-mode} or
|
|
|
12 @code{manual-entry}. The use of English words makes the command name
|
|
|
13 easier to remember than a key made up of obscure characters, even though
|
|
|
14 it results in more characters to type. You can run any command by name,
|
|
|
15 even if it can be run by keys as well.
|
|
|
16
|
|
|
17 @kindex M-x
|
|
|
18 @cindex minibuffer
|
|
|
19 To run a command by name, start with @kbd{M-x}, then type the
|
|
|
20 command name, and finish with @key{RET}. @kbd{M-x} uses the minibuffer
|
|
|
21 to read the command name. @key{RET} exits the minibuffer and runs the
|
|
|
22 command.
|
|
|
23
|
|
|
24 Emacs uses the minibuffer for reading input for many different purposes;
|
|
|
25 on this occasion, the string @samp{M-x} is displayed at the beginning of
|
|
|
26 the minibuffer as a @dfn{prompt} to remind you that your input should be
|
|
|
27 the name of a command to be run. @xref{Minibuffer}, for full information
|
|
|
28 on the features of the minibuffer.
|
|
|
29
|
|
|
30 You can use completion to enter a command name. For example, to
|
|
|
31 invoke the command @code{forward-char}, type:
|
|
|
32
|
|
|
33 @example
|
|
|
34 M-x forward-char @key{RET}
|
|
|
35 @end example
|
|
|
36 or
|
|
|
37 @example
|
|
|
38 M-x fo @key{TAB} c @key{RET}
|
|
|
39 @end example
|
|
|
40
|
|
|
41 @noindent
|
|
|
42 After you type in @code{M-x fo TAB} emacs will give you a possible list of
|
|
|
43 completions from which you can choose. Note that @code{forward-char} is the
|
|
|
44 same command that you invoke with the key @kbd{C-f}. You can call any
|
|
|
45 command (interactively callable function) defined in Emacs by its name
|
|
|
46 using @kbd{M-x} regardless of whether or not any keys are bound to it.
|
|
|
47
|
|
|
48 If you type @kbd{C-g} while Emacs reads the command name, you cancel
|
|
|
49 the @kbd{M-x} command and get out of the minibuffer, ending up at top level.
|
|
|
50
|
|
|
51 To pass a numeric argument to a command you are invoking with
|
|
|
52 @kbd{M-x}, specify the numeric argument before the @kbd{M-x}. @kbd{M-x}
|
|
|
53 passes the argument along to the function that it calls. The argument
|
|
|
54 value appears in the prompt while the command name is being read.
|
|
|
55
|
|
|
56 @findex interactive
|
|
|
57 You can use the command @code{M-x interactive} to specify a way of
|
|
|
58 parsing arguments for interactive use of a function. For example, write:
|
|
|
59
|
|
|
60 @example
|
|
|
61 (defun foo (arg) "Doc string" (interactive "p") ...use arg...)
|
|
|
62 @end example
|
|
|
63
|
|
|
64 to make @code{arg} be the prefix argument when @code{foo} is called as a
|
|
|
65 command. The call to @code{interactive} is actually a declaration
|
|
|
66 rather than a function; it tells @code{call-interactively} how to read
|
|
|
67 arguments to pass to the function. When actually called, @code{interactive}
|
|
|
68 returns @code{nil}.
|
|
|
69
|
|
|
70 The argument of @var{interactive} is usually a string containing a code
|
|
|
71 letter followed by a prompt. Some code letters do not use I/O to get
|
|
|
72 the argument and do not need prompts. To prompt for multiple arguments,
|
|
|
73 you must provide a code letter, its prompt, a newline, and another code
|
|
|
74 letter, and so forth. If the argument is not a string, it is evaluated
|
|
|
75 to get a list of arguments to pass to the function. If you do not provide an
|
|
|
76 argument to @code{interactive}, no arguments are passed when calling
|
|
|
77 interactively.
|
|
|
78
|
|
|
79 Available code letters are:
|
|
|
80
|
|
|
81 @table @code
|
|
|
82 @item a
|
|
|
83 Function name: symbol with a function definition
|
|
|
84 @item b
|
|
|
85 Name of existing buffer
|
|
|
86 @item B
|
|
|
87 Name of buffer, possibly nonexistent
|
|
|
88 @item c
|
|
|
89 Character
|
|
|
90 @item C
|
|
|
91 Command name: symbol with interactive function definition
|
|
|
92 @item d
|
|
|
93 Value of point as number (does not do I/O)
|
|
|
94 @item D
|
|
|
95 Directory name
|
|
|
96 @item e
|
|
|
97 Last mouse event
|
|
|
98 @item f
|
|
|
99 Existing file name
|
|
|
100 @item F
|
|
|
101 Possibly nonexistent file name
|
|
|
102 @item k
|
|
|
103 Key sequence (string)
|
|
|
104 @item m
|
|
|
105 Value of mark as number (does not do I/O)
|
|
|
106 @item n
|
|
|
107 Number read using minibuffer
|
|
|
108 @item N
|
|
|
109 Prefix arg converted to number, or if none, do like code @code{n}
|
|
|
110 @item p
|
|
|
111 Prefix arg converted to number (does not do I/O)
|
|
|
112 @item P
|
|
|
113 Prefix arg in raw form (does not do I/O)
|
|
|
114 @item r
|
|
|
115 Region: point and mark as two numeric arguments, smallest first (does
|
|
|
116 not do I/O)
|
|
|
117 @item s
|
|
|
118 Any string
|
|
|
119 @item S
|
|
|
120 Any symbol
|
|
|
121 @item v
|
|
|
122 Variable name: symbol that is @code{user-variable-p}
|
|
|
123 @item x
|
|
|
124 Lisp expression read but not evaluated
|
|
|
125 @item X
|
|
|
126 Lisp expression read and evaluated
|
|
|
127 @end table
|
|
|
128
|
|
|
129 In addition, if the string begins with @samp{*}, an error is
|
|
|
130 signaled if the buffer is read-only. This happens before reading any
|
|
|
131 arguments. If the string begins with @samp{@@}, the window the mouse is
|
|
|
132 over is selected before anything else is done. You may use both
|
|
|
133 @samp{@@} and @samp{*}; they are processed in the order that they appear.
|
|
|
134
|
|
|
135 Normally, when describing a command that is run by name, we omit the
|
|
|
136 @key{RET} that is needed to terminate the name. Thus we may refer to
|
|
|
137 @kbd{M-x auto-fill-mode} rather than @kbd{M-x auto-fill-mode} @key{RET}.
|
|
|
138 We mention the @key{RET} only when it is necessary to emphasize its
|
|
|
139 presence, for example, when describing a sequence of input that contains
|
|
|
140 a command name and arguments that follow it.
|
|
|
141
|
|
|
142 @findex execute-extended-command
|
|
|
143 @kbd{M-x} is defined to run the command @code{execute-extended-command},
|
|
|
144 which is responsible for reading the name of another command and invoking
|
|
|
145 it.
|
