Elisp: Text Editing Functions

By Xah Lee. Date: . Last updated: .

Here's the most used functions related to text editing.

Insert Text to Current Buffer at Cursor Position

the following functions insert text to current cursor position. [see Cursor Position Functions]

insert
(insert &rest ARGS)

Insert string. 

;; insert string
(insert "sun and moon")
insert-buffer-substring
(insert-buffer-substring BUFFER &optional START END)

Insert from BUFFER to current buffer.

insert-file-contents
(insert-file-contents FILENAME &optional VISIT BEG END REPLACE)

Insert contents of file FILENAME.

Insert Text to Specific Buffer

insert-into-buffer
(insert-into-buffer BUFFER &optional START END)

Insert text from current buffer into another BUFFER.

append-to-buffer

(append-to-buffer BUFFER START END)

copy current buffer START END region into buffer BUFFER, at that buffer's cursor position.

prepend-to-buffer

Delete Text

delete-char

Delete n characters to the right. Use negative number to delete to the left. 

;; delete 9 chars starting at cursor pos
(delete-char 9)
delete-region

(delete-region START END)

  • Delete text between 2 positions. Order of positions does not matter.
  • return nil

the cursor may be moved after the call:

  • If cursor is before the region, no change.
  • If cursor is between the region, it is moved to START.
  • If cursor is after the region, point is updated accordingly. (i.e. Point stay with the text.)

💡 TIP: you may want to always call goto-char after, so the cursor position is explicit. 

;; deleting text between positions 59 and 896
(delete-region 59 896)
erase-buffer

Delete all text in buffer, ignores Narrow to Region. 

(erase-buffer)
delete-and-extract-region

Delete between 2 positions and return the deleted text. 

(delete-and-extract-region 3 20)

Reference

Elisp, text processing functions