Emacs Lisp: Read File
Open File for Reading in Batch Script
To process thousands of files, read only, use
(defun my-process-file (fPath) "Process the file at path FPATH" (with-temp-buffer (insert-file-contents fPath) ;; do something ))
To write to file, us
in the body.
Emacs Lisp: Write File
(info "(elisp) Current Buffer")
Read File as String or List of Lines
Emacs Lisp: Read File Content as String or List of Lines
(find-file FILENAME &optional WILDCARDS)
Creates a new buffer, associate it with FILENAME, switch to the buffer. Return a buffer object. FILENAME can be a full path or just a file name. This can be used to create a new file, when FILENAME does not exist. When the buffer is saved, the file will be created.
find-fileis very slow, because it has lots side-effects. example:
- Loads a major mode (which does syntax coloring, usually very slow),
- Record undo for any modification in the buffer.
- Calls functions in find-file-hook.
Here's example of functions that are added to find-file-hook that slows down emacs.
find-file-hook is a variable defined in 'files.el'. Its value is (global-xah-math-input-mode-check-buffers url-handlers-set-buffer-mode global-display-line-numbers-mode-check-buffers auto-revert--global-adopt-current-buffer auto-revert-find-file-function recentf-track-opened-file epa-file-find-file-hook global-eldoc-mode-check-buffers global-font-lock-mode-check-buffers vc-refresh-state save-place-find-file-hook) Original value was nil
if you really want to open the file as buffer in your batch script, then the following is helpful to speed it up:
(global-font-lock-mode 0) (setq find-file-hook nil) (setq buffer-undo-list t)
[see Emacs Lisp Text Processing: find-file vs with-temp-buffer]
(kill-buffer &optional BUFFER-OR-NAME)
Close current buffer or a specified buffer.
;; close a buffer (kill-buffer myBuffName)