X-Git-Url: https://code.delx.au/gnu-emacs/blobdiff_plain/cd30a00e854ab2b7f1388ea1ac726ac76c1a078f..937640a621a4ce2e5e56eaecca37a2a28a584318:/man/commands.texi diff --git a/man/commands.texi b/man/commands.texi index d7bdb75ecb..54ec50acfe 100644 --- a/man/commands.texi +++ b/man/commands.texi @@ -10,38 +10,42 @@ of @dfn{keys} and @dfn{commands}, which are fundamental for understanding how Emacs interprets your keyboard and mouse input. @end iftex +@ifnottex +@raisesections +@end ifnottex + @node User Input, Keys, Screen, Top @section Kinds of User Input @cindex input with the keyboard @cindex keyboard input @cindex character set (keyboard) -@cindex ASCII +@cindex @acronym{ASCII} @cindex C- @cindex Control @cindex control characters - GNU Emacs uses an extension of the ASCII character set for keyboard + GNU Emacs uses an extension of the @acronym{ASCII} character set for keyboard input; it also accepts non-character input events including function keys and mouse button actions. - ASCII consists of 128 character codes. Some of these codes are + @acronym{ASCII} consists of 128 character codes. Some of these codes are assigned graphic symbols such as @samp{a} and @samp{=}; the rest are control characters, such as @kbd{Control-a} (usually written @kbd{C-a} for short). @kbd{C-a} gets its name from the fact that you type it by holding down the @key{CTRL} key while pressing @kbd{a}. - Some ASCII control characters have special names, and most terminals + Some @acronym{ASCII} control characters have special names, and most terminals have special keys you can type them with: for example, @key{RET}, @key{TAB}, @key{DEL} and @key{ESC}. The space character is usually referred to below as @key{SPC}, even though strictly speaking it is a graphic character whose graphic happens to be blank. Some keyboards have a key labeled ``linefeed'' which is an alias for @kbd{C-j}. - Emacs extends the ASCII character set with thousands more printing + Emacs extends the @acronym{ASCII} character set with thousands more printing characters (@pxref{International}), additional control characters, and a few more modifiers that can be combined with any character. - On ASCII terminals, there are only 32 possible control characters. + On @acronym{ASCII} terminals, there are only 32 possible control characters. These are the control variants of letters and @samp{@@[]\^_}. In addition, the shift key is meaningless with control characters: @kbd{C-a} and @kbd{C-A} are the same character, and Emacs cannot @@ -76,11 +80,15 @@ key with some other primary purpose. Sometimes it is labeled it. If there is no @key{META} key, you can still type Meta characters -using two-character sequences starting with @key{ESC}. Thus, you can enter -@kbd{M-a} by typing @kbd{@key{ESC} a}. You can enter @kbd{C-M-a} by -typing @kbd{@key{ESC} C-a}. @key{ESC} is allowed on terminals with -@key{META} keys, too, in case you have formed a habit of using it. - +using two-character sequences starting with @key{ESC}. Thus, you can +enter @kbd{M-a} by typing @kbd{@key{ESC} a}. You can enter +@kbd{C-M-a} by typing @kbd{@key{ESC} C-a}. Unlike @key{META}, which +modifies other characters, @key{ESC} is a separate character. You +don't hold down @key{ESC} while typing the next character; instead, +you press it and release it, then you enter the next character. +@key{ESC} is allowed on terminals with @key{META} keys, too, in case +you have formed a habit of using it. + The X Window System provides several other modifier keys that can be applied to any input character. These are called @key{SUPER}, @key{HYPER} and @key{ALT}. We write @samp{s-}, @samp{H-} and @samp{A-} @@ -92,6 +100,14 @@ key bindings of Emacs do not include any characters with these modifiers. But you can assign them meanings of your own by customizing Emacs. + If your keyboard lacks one of these modifier keys, you can enter it +using @kbd{C-x @@}: @kbd{C-x @@ h} adds the ``hyper'' flag to the next +character, @kbd{C-x @@ s} adds the ``super'' flag, and @kbd{C-x @@ a} +adds the ``alt'' flag. For instance, @kbd{C-x @@ h C-a} is a way to +enter @kbd{Hyper-Control-a}. (Unfortunately there is no way to add +two modifiers by using @kbd{C-x @@} twice for the same character, +because the first one goes to work on the @kbd{C-x}.) + Keyboard input includes keyboard keys that are not characters at all: for example function keys and arrow keys. Mouse buttons are also outside the gamut of characters. You can modify these events with the @@ -105,8 +121,8 @@ Reference Manual}, for more information. If you are not doing Lisp programming, but simply want to redefine the meaning of some characters or non-character events, see @ref{Customization}. - ASCII terminals cannot really send anything to the computer except -ASCII characters. These terminals use a sequence of characters to + @acronym{ASCII} terminals cannot really send anything to the computer except +@acronym{ASCII} characters. These terminals use a sequence of characters to represent each function key. But that is invisible to the Emacs user, because the keyboard input routines recognize these special sequences and convert them to function key events before any other part of Emacs @@ -171,7 +187,7 @@ There are a few prefix keys for which @kbd{C-h} does not work---for historical reasons, they have other meanings for @kbd{C-h} which are not easy to change. But @key{F1} should work for all prefix keys. - + @node Commands, Text Characters, Keys, Top @section Keys and Commands @@ -231,25 +247,33 @@ variables will make sense. @xref{Variables}. @cindex characters (in text) Text in Emacs buffers is a sequence of 8-bit bytes. Each byte can -hold a single ASCII character. Both ASCII control characters (octal -codes 000 through 037, and 0177) and ASCII printing characters (codes -040 through 0176) are allowed; however, non-ASCII control characters +hold a single @acronym{ASCII} character. Both @acronym{ASCII} control characters (octal +codes 000 through 037, and 0177) and @acronym{ASCII} printing characters (codes +040 through 0176) are allowed; however, non-@acronym{ASCII} control characters cannot appear in a buffer. The other modifier flags used in keyboard input, such as Meta, are not allowed in buffers either. - Some ASCII control characters serve special purposes in text, and have + Some @acronym{ASCII} control characters serve special purposes in text, and have special names. For example, the newline character (octal code 012) is used in the buffer to end a line, and the tab character (octal code 011) is used for indenting to the next tab stop column (normally every 8 columns). @xref{Text Display}. - Non-ASCII printing characters can also appear in buffers. When -multibyte characters are enabled, you can use any of the non-ASCII + Non-@acronym{ASCII} printing characters can also appear in buffers. When +multibyte characters are enabled, you can use any of the non-@acronym{ASCII} printing characters that Emacs supports. They have character codes starting at 256, octal 0400, and each one is represented as a sequence of two or more bytes. @xref{International}. Single-byte characters with codes 128 through 255 can also appear in multibyte buffers. If you disable multibyte characters, then you can use only one -alphabet of non-ASCII characters, but they all fit in one byte. They +alphabet of non-@acronym{ASCII} characters, but they all fit in one byte. They use codes 0200 through 0377. @xref{Single-Byte Character Support}. + +@ifnottex +@lowersections +@end ifnottex + +@ignore + arch-tag: 9be43eef-d1f4-4d03-a916-c741ea713a45 +@end ignore