32.5 User-Level Insertion Commands

This section describes higher-level commands for inserting text, commands intended primarily for the user but useful also in Lisp programs.

command insert-buffer from-buffer-or-name

This command inserts the entire accessible contents of from-buffer-or-name (which must exist) into the current buffer after point. It leaves the mark after the inserted text. The value is nil.

command self-insert-command count \&optional char

This command inserts the character char (the last character typed); it does so count times, before point, and returns nil. Most printing characters are bound to this command. In routine use, self-insert-command is the most frequently called function in Emacs, but programs rarely use it except to install it on a keymap.

In an interactive call, count is the numeric prefix argument.

Self-insertion translates the input character through translation-table-for-input. See Translation of Characters.

This command calls auto-fill-function whenever that is non-nil and the character inserted is in the table auto-fill-chars (see Auto Filling).

This command performs abbrev expansion if Abbrev mode is enabled and the inserted character does not have word-constituent syntax. (See Abbrevs, and Syntax Class Table.) It is also responsible for calling blink-paren-function when the inserted character has close parenthesis syntax (see Blinking).

The final thing this command does is to run the hook post-self-insert-hook. You could use this to automatically reindent text as it is typed, for example. If any function on this hook needs to act on the region (see The Region), it should make sure Delete Selection mode (see Delete Selection in The GNU Emacs Manual) doesn’t delete the region before post-self-insert-hook functions are invoked. The way to do so is to add a function that returns nil to self-insert-uses-region-functions, a special hook that tells Delete Selection mode it should not delete the region.

Do not try substituting your own definition of self-insert-command for the standard one. The editor command loop handles this function specially.

command newline \&optional number-of-newlines interactive

This command inserts newlines into the current buffer before point. If number-of-newlines is supplied, that many newline characters are inserted. In an interactive call, number-of-newlines is the numeric prefix argument.

This command calls self-insert-command to insert newlines, which may subsequently break the preceding line by calling auto-fill-function (see Auto Filling). Typically what auto-fill-function does is insert a newline; thus, the overall result in this case is to insert two newlines at different places: one at point, and another earlier in the line. newline does not auto-fill if number-of-newlines is non-nil.

This command does not run the hook post-self-insert-hook unless called interactively or interactive is non-nil.

This command indents to the left margin if that is not zero. See Margins.

The value returned is nil.

variable overwrite-mode

This variable controls whether overwrite mode is in effect. The value should be overwrite-mode-textual, overwrite-mode-binary, or nil. overwrite-mode-textual specifies textual overwrite mode (treats newlines and tabs specially), and overwrite-mode-binary specifies binary overwrite mode (treats newlines and tabs like any other characters).