This function stops Emacs and returns control to the superior process. If and when the superior process resumes Emacs, suspend-emacs returns nil to its caller in Lisp.

This function works only on the controlling terminal of the Emacs session; to relinquish control of other tty devices, use suspend-tty (see below). If the Emacs session uses more than one terminal, you must delete the frames on all the other terminals before suspending Emacs, or this function signals an error. See Multiple Terminals.

If string is non-nil, its characters are sent to Emacs’s superior shell, to be read as terminal input. The characters in string are not echoed by the superior shell; only the results appear.

Before suspending, suspend-emacs runs the normal hook suspend-hook. After the user resumes Emacs, suspend-emacs runs the normal hook suspend-resume-hook. See Hooks.

The next redisplay after resumption will redraw the entire screen, unless the variable no-redraw-on-reenter is non-nil. See Refreshing the Screen.

Here is an example of how you could use these hooks:

Here is what you would see upon evaluating (suspend-emacs "pwd"):

Note that ‘pwd’ is not echoed after Emacs is suspended. But it is read and executed by the shell.