3 Entering and Exiting Emacs

The usual way to invoke SXEmacs is to type sxemacs RET at the shell. SXEmacs clears the screen and then displays an initial advisory message and copyright notice. You can begin typing SXEmacs commands immediately afterward.

Some operating systems insist on discarding all type-ahead when SXEmacs starts up; they give SXEmacs no way to prevent this. Therefore, it is advisable to wait until SXEmacs clears the screen before typing your first editing command.

If you run SXEmacs from a shell window under the X Window System, run it in the background with ‘sxemacs&’. This way, SXEmacs does not tie up the shell window, so you can use that to run other shell commands while SXEmacs operates its own X windows. You can begin typing SXEmacs commands as soon as you direct your keyboard input to the SXEmacs frame.

Before Emacs reads the first command, you have not had a chance to give a command to specify a file to edit. Since Emacs must always have a current buffer for editing, it presents a buffer, by default, a buffer named ‘*scratch*’. The buffer is in Lisp Interaction mode; you can use it to type Lisp expressions and evaluate them, or you can ignore that capability and simply doodle. (You can specify a different major mode for this buffer by setting the variable initial-major-mode in your init file. See Init File.)

It is possible to specify files to be visited, Lisp files to be loaded, and functions to be called, by giving Emacs arguments in the shell command line. See Command Switches. But we don’t recommend doing this. The feature exists mainly for compatibility with other editors.

Many other editors are designed to be started afresh each time you want to edit. You edit one file and then exit the editor. The next time you want to edit either another file or the same one, you must run the editor again. With these editors, it makes sense to use a command-line argument to say which file to edit.

But starting a new Emacs each time you want to edit a different file does not make sense. For one thing, this would be annoyingly slow. For another, this would fail to take advantage of Emacs’s ability to visit more than one file in a single editing session. And it would lose the other accumulated context, such as registers, undo history, and the mark ring.

The recommended way to use SXEmacs is to start it only once, just after you log in, and do all your editing in the same Emacs session. Each time you want to edit a different file, you visit it with the existing Emacs, which eventually comes to have many files in it ready for editing. Usually you do not kill the Emacs until you are about to log out. See Files, for more information on visiting more than one file.