Compile and run single file c++ programs in Emacs[SOLVED]

Question

I want to bind to a key a compile-and-run function to be able to compile my C++ single file programs and run them into a term/shell so I could give my variables values whenever I use cin in my programs.

For example, in my Neovim config, I had this line:

autocmd FileType cpp  nnoremap <F8> :w <CR> :vsp <CR> <C-w>l :term g++ % -o %< && ./%< <CR> i

I want to have something similar in Emacs. In Emacs, this line will be looking like so:

(define-key c++-mode-map (kbd "<f8>") #'compileandrun)

But I have no clue how the compileandrun function will look.

edit 1: Here is a function I have tried

(defun compileandrun()
  (interactive)
  (compile (concat "g++ "  (file-name-nondirectory (buffer-file-name)) " -o " (file-name-sans-extension   (file-name-nondirectory 
           (buffer-file-name)))))
   (term  (concat "./" (file-name-sans-extension
           (file-name-nondirectory (buffer-file-name))))))

it only compiles the program but it dosen't run it .

Please put your answer in its own post rather than include it in the question. It's fine to self-answer. — Dan, Jan 07 '20 at 02:04

Tobias · Answer 1 · 2021-01-23T04:10:22.250

2

compile uses the shell. You can chain program execution with && like g++ test.cc -o test && ./test. With the last command ./test is executed if compilation with g++ succeeds.

I'll modify your command accordingly:

(defun compileandrun()
  (interactive)
  (let* ((src (file-name-nondirectory (buffer-file-name)))
         (exe (file-name-sans-extension src)))
    (compile (concat "g++ " src " -o " exe " && ./" exe))))

edited Jan 23 '21 at 04:10

answered Jan 06 '20 at 14:06

Tobias

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You will need to use let* form here because 'src' variable is used inside the 'exe' binding; otherwise you will get error about void variable for 'src' – cmaceachern Jan 22 '21 at 16:36
@crajun Thanks, corrected. – Tobias Jan 23 '21 at 04:10

score 1 · Answer 2 · answered Jan 07 '20 at 11:23

Here is the final elisp function that works. It automatically switches to the window and move the cursor to the bottom .

(defun compileandrun()
  (interactive)
  (save-buffer)
  (compile (concat "g++ "  (file-name-nondirectory (buffer-file-name)) " -o " (file-name-sans-extension   (file-name-nondirectory (buffer-file-name))) " && ./" (file-name-sans-extension  (file-name-nondirectory (buffer-file-name)))) t )
(other-window 1)
(end-of-buffer)
) 
(add-hook 'c++-mode-hook
          (lambda () (local-set-key (kbd "<f8>") #'compileandrun)))

If you have any improvments let me know .

Compile and run single file c++ programs in Emacs[SOLVED]

2 Answers2

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