I am running emacsclient with the command:
emacsclient -t -a "" --eval "some-exp"
The emacsclient -t -a "" is a must.
The problem is, for example, if I run:
emacsclient -t -a "" --eval "nil"
when quitting emacsclient, the command line will have "nil" printed.
My question is, how to totally stop the printing of the returned value ? (in here, it's nil).
I don't really understand your concern. emacsclient's --eval/-e always eval one expression and print the result to stdout, if you don't care about the result, simply ignore it or redirect it to /dev/null. Anyway, it's easy to stop printing, you can use
(define-advice server-eval-and-print (:filter-args (args) no-print)
(list (car args) nil))
to advice server-eval-and-print to just eval and bypass print. It should be easy to know how it works by taking a look at the function server-eval-and-print in source code.
If you don't have define-advice, which was added in Emacs 25.1, use this instead:
(defun server-eval-and-print@no-print (args)
(list (car args) nil))
(advice-add 'server-eval-and-print :filter-args
#'server-eval-and-print@no-print)
server-eval-and-print do the evaluation: (eval (car (read-from-string expr))), so if you pass multiple sexp, it always the first one and ignore the rest.
– xuchunyang
Nov 30 '16 at 5:16
--eval/-e. I don't understand why you need use -t and --eval/-e together. the -t makes no sense when --eval/-e exists, though It's should be OK. Of course, you can't do something like emacsclient -t foo.txt > /dev/null or vi foo.txt > /dev/null.
– xuchunyang
Nov 30 '16 at 5:31
STDERRInstead be acceptable? – Melioratus Nov 29 '16 at 5:50