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(elisp)Describing Characters

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Describing Characters for Help Messages
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   These functions convert events, key sequences, or characters to
textual descriptions.  These descriptions are useful for including
arbitrary text characters or key sequences in messages, because they
convert non-printing and whitespace characters to sequences of printing
characters.  The description of a non-whitespace printing character is
the character itself.

 - Function: key-description sequence
     This function returns a string containing the Emacs standard
     notation for the input events in SEQUENCE.  The argument SEQUENCE
     may be a string, vector or list.  Note: Input Events, for more
     information about valid events.  See also the examples for
     `single-key-description', below.

 - Function: single-key-description event &optional no-angles
     This function returns a string describing EVENT in the standard
     Emacs notation for keyboard input.  A normal printing character
     appears as itself, but a control character turns into a string
     starting with `C-', a meta character turns into a string starting
     with `M-', and space, tab, etc. appear as `SPC', `TAB', etc.  A
     function key symbol appears inside angle brackets `<...>'.  An
     event that is a list appears as the name of the symbol in the CAR
     of the list, inside angle brackets.

     If the optional argument NO-ANGLES is non-`nil', the angle
     brackets around function keys and event symbols are omitted; this
     is for compatibility with old versions of Emacs which didn't use
     the brackets.

          (single-key-description ?\C-x)
               => "C-x"
          (key-description "\C-x \M-y \n \t \r \f123")
               => "C-x SPC M-y SPC C-j SPC TAB SPC RET SPC C-l 1 2 3"
          (single-key-description 'delete)
               => "<delete>"
          (single-key-description 'C-mouse-1)
               => "<C-mouse-1>"
          (single-key-description 'C-mouse-1 t)
               => "C-mouse-1"

 - Function: text-char-description character
     This function returns a string describing CHARACTER in the
     standard Emacs notation for characters that appear in text--like
     `single-key-description', except that control characters are
     represented with a leading caret (which is how control characters
     in Emacs buffers are usually displayed).

          (text-char-description ?\C-c)
               => "^C"
          (text-char-description ?\M-m)
               => "M-m"
          (text-char-description ?\C-\M-m)
               => "M-^M"

 - Function: read-kbd-macro string
     This function is used mainly for operating on keyboard macros, but
     it can also be used as a rough inverse for `key-description'.  You
     call it with a string containing key descriptions, separated by
     spaces; it returns a string or vector containing the corresponding
     events.  (This may or may not be a single valid key sequence,
     depending on what events you use; Note: Keymap Terminology.)