Launching shell command in Eshell without prompt interfence - emacs

I'm trying to customize my eshell to intercept python to do two things:
Open a new window and run python if no arguments are given (e.g., $ python)
Run the command "per usual" if arguments are given (e.g., $ python foobar.py)
So far I have something like this
(defun eshell/python (&rest cmd-args)
(if (not cmd-args)
(progn (run-python "python")
(select-window (split-window-below))
(switch-to-buffer "*Python*")
(balance-windows)
nil)
(message "Use '*python' to call python directly")))
I've tried replacing (message ...) with a few different things:
Based on the ouput of eshell-parse-command "python test.py" I tried
(progn (eshell-trap-errors
(eshell-named-command "python" cmd-args)))
but it hits a recursion limit.
Since *python test.py does what I want, I then tried
(progn (eshell-trap-errors
(eshell-named-command (concat "*" "python") cmd-args)))
but that puts the python process in the background and interrupts stdout with the output of my eshell-prompt-function.
Finally, I've fiddled with shell-command but I can't get it to write to the eshell buffer. In particular,
(progn (eshell-trap-errors
(shell-command (mapconcat (lambda(x) x) cmd-args " ")
(get-buffer "*eshell*") (get-buffer "*eshell*"))))
gives me a Text is read only message and moves point to start of the eshell buffer.
Is what I'm looking for possible?
Edit 1
Running without eshell/python defined, I've instead tried to avoid alias problems:
(defun eshell/gvr (&rest cmd-args)
(if (not cmd-args)
(progn (run-python "python")
(select-window (split-window-below))
(switch-to-buffer "*Python*")
(balance-windows)
nil)
(progn (eshell-trap-errors
(eshell-named-command "python" cmd-args)))))
If test.py is
print "Hello World"
x = raw_input("What should I repeat? ")
print x
running gvr test.py in eshell fails when I reply to the prompt because eshell tries to execute the input instead of handing it to python, but running python test.py goes off without a hitch.
How can I get run my own subprocesses in eshell the same way that they happen by default?

Related

emacs: How to Capture stdout from dired-do-shell-command?

In Emacs, is there a way to capture the stdout of dired-do-shell-command, say to the kill-ring?
Without knowing how, I end up going to the Messages buffer and getting the stdout manually from there.
Help for that command says that output goes to a buffer named *Shell Command Output*, assuming command has not &. If this is the case, this piece of code will do what you want:
(defun do-shell-and-copy-to-kill-ring (command &optional arg file-list)
(interactive
(let ((files (dired-get-marked-files t current-prefix-arg)))
(list
(dired-read-shell-command "! on %s: " current-prefix-arg files)
current-prefix-arg
files)))
(dired-do-shell-command command arg file-list)
(with-current-buffer "*Shell Command Output*"
(copy-region-as-kill (point-min) (point-max))))
For async commands, you need to wait for them and look in *Async Shell Command* buffer.

restart process executed in eshell in emacs

i have started a python process in eshell:
python app.py
i want to restart this with a elisp function, i think comint-quit-subjob when executed with C-c C-\ kills the process but all my attempts to execute comint-quit-subjob have failed
This is what i have so far:
(defun restart-app()
(with-current-buffer "*eshell*"
(interactive)
(comint-quit-subjob)
(eshell-return-to-prompt)
(insert "python app.py")
(eshell-send-input))
)
Hopefully it gives the jist of what i am trying, but it fails. Any ideas?
I would suggest looking for a eshell-ish way of killing a process (I am not a eshell user myself). Comint tries to search something in the buffer. You can workaround that doing something like this (but it is brittle and unelegant):
(defun restart-app()
(with-current-buffer "*eshell*"
(interactive)
(kill-process nil comint-ptyp)
(run-with-timer 0.5 nil
(lambda ()
(with-current-buffer "*eshell*"
(goto-char (point-max))
(insert "python app.py")
(eshell-send-input)))))

How to define an alternate command for emacs eshell

I'm trying to start using eshell in place of bash within emacs, but I rely heavily on bash functions that I have written over the years. I'd like to configure eshell to invoke bash whenever a "command not found" condition occurs, in case the command in question is implemented as a bash function.
There is a variable tantalizingly named eshell-alternate-command-hook that sounds like it is made to order, but my lack of elisp skill is interfering with my success I think.
This is my best effort:
(add-hook 'eshell-alternate-command-hook 'invoke-bash t t)
(defun invoke-bash (command args)
(throw 'eshell-replace-command
(list "bash -c" command args)))
But when I test it, it doesn't work:
c:/temp $ lsd
Wrong number of arguments: (lambda (command args) (throw (quote eshell-replace-command) (list "bash -c" command args))), 1
c:/temp $
This is what I eventually came up with:
(defun invoke-bash (command)
(progn
(setq invoke-bash-cmd (concat "bash -c \"" command " " (mapconcat 'identity eshell-last-arguments " ") "\""))
(message invoke-bash-cmd)
(throw 'eshell-replace-command
(eshell-parse-command invoke-bash-cmd))))
I'm not eshell guru, but in the place where this hook is used, I see that it receives only one argument - command, that you trying to execute, so your code could look like
(add-hook 'eshell-alternate-command-hook 'invoke-bash)
(defun invoke-bash (command)
(throw 'eshell-replace-command
(list "bash -c" command)))
but it doesn't work, because you need to return elisp function, not name of command (according to documentation). If you want to run bash, then you need to return string with full path to it, but I hadn't found how to pass additional arguments to bash. Maybe you can find more in corresponding section on Emacs Wiki?

Using Emacs, is it possible to pin the compilation command to a specific buffer/directory?

Right now I am using the following to compile, when I'm in for example main.cpp
C-x b Makefile RET M-x compile RET RET
I actually have M-x compile as a keyboard shortcut, but the problem is I would really like not having to go through all that trouble to simply run my Makefile.
I need to visit Makefile to make sure the compile command is executed using the same directory. Is there any way to pin the directory so I can simply go M-x compile RET RET?
Best regards
Use recompile instead. C-u M-x recompile will let you edit the compile command first. Either way the compile will work out of the directory the last compile was done in.
See my answer here
Directory local variables provide an easy way to trigger the compile from a parent directory of any source file in a subdirectory.
I run emacs primarily on windows.
When I have a makefile that is in a parent directory of a C module, I use this as the compile command:
cd .. && nmake <arguments here>
for example:
cd .. && nmake CONFIG=Debug PLATFORM=x64 target
Beyond that, I find that specifying the make command line that I want to run for various modules is sort of a pain. I wanted a way to attach the default compile command to the buffer being edited. So I wrote a little elisp to handle that job. I figured to insert into the header comments of each buffer a line that would stipulate my preferred compile command, like this:
compile: cd .. && nmake CONFIG=Debug PLATFORM=x64 target
And then have a piece of elisp run, before I invoke M-x compile that grabs the line and proposes it as the compile command I would like to run.
This defun pulls a line out of the header comments:
(defun cheeso-c-get-value-from-comments (marker-string line-limit)
"gets a string from the header comments in the current buffer.
This is used to extract the compile command from the comments. It
could be used for other purposes too.
It looks for \"marker-string:\" and returns the string that
follows it, or returns nil if that string is not found.
eg, when marker-string is \"compile\", and the following
string is found at the top of the buffer:
compile: cl.exe /I uthash
...then this command will return the string
\"cl.exe /I uthash\"
It's ok to have whitespace between the marker and the following
colon.
"
(let (start search-limit found)
;; determine what lines to look in
(save-excursion
(save-restriction
(widen)
(cond ((> line-limit 0)
(goto-char (setq start (point-min)))
(forward-line line-limit)
(setq search-limit (point)))
((< line-limit 0)
(goto-char (setq search-limit (point-max)))
(forward-line line-limit)
(setq start (point)))
(t ;0 => no limit (use with care!)
(setq start (point-min))
(setq search-limit (point-max))))))
;; look in those lines
(save-excursion
(save-restriction
(widen)
(let ((re-string
(concat "\\b" marker-string "[ \t]*:[ \t]*\\(.+\\)$")))
(if (and start
(< (goto-char start) search-limit)
(re-search-forward re-string search-limit 'move))
(buffer-substring-no-properties
(match-beginning 1)
(match-end 1))))))))
Ok, now I need something to invoke that before I invoke compile.
(defun cheeso-invoke-compile-interactively ()
"fn to wrap the `compile' function. This simply
checks to see if `compile-command' has been previously set, and
if not, invokes `cheeso-guess-compile-command' to set the value.
Then it invokes the `compile' function, interactively."
(interactive)
(cond
((not (boundp 'cheeso-local-compile-command-has-been-set))
(cheeso-guess-compile-command)
(set (make-local-variable 'cheeso-local-compile-command-has-been-set) t)))
;; local compile command has now been set
(call-interactively 'compile))
Then of course, the defun that guesses the compile command:
(defun cheeso-guess-compile-command ()
"set `compile-command' intelligently depending on the
current buffer, or the contents of the current directory."
(interactive)
(set (make-local-variable 'compile-command)
(cond
(buffer-file-name
(let ((filename (file-name-nondirectory buffer-file-name)))
(cond
;; editing a C-language source file - check for an
;; explicitly-specified command
((string-equal (substring buffer-file-name -2) ".c")
(let ((explicit-compile-command
(cheeso-c-get-value-from-comments "compile" 34)))
(or explicit-compile-command
(concat "nmake " ;; assume a makefile exists
(file-name-sans-extension filename)
".exe"))))
;; editing a makefile - just run nmake
((string-equal (substring buffer-file-name -8) "makefile")
"nmake ")
;; something else - do a typical .exe build
(t
(concat "nmake "
(file-name-sans-extension filename)
".exe")))))
(t
;; punt
"nmake "))))
The final bit is to bind C-x C-e , normally bound to compile, to the wrapper defun:
(global-set-key "\C-x\C-e" 'cheeso-invoke-compile-interactively)
Now, when I do C-x C-e in the buffer, it searches for the compile command, and proposes to me the command that it finds. I can edit the proposed compile command, then press ENTER and run it.

Why is my term-mode-hook not selecting line mode?

I wrote this elisp function:
(defun run (command)
"Open a terminal running a command."
(interactive "sCommand: ")
(if (buffer-exists (concat "*" command "*" )) (kill-buffer (concat "*" command "*")))
(let ((term-mode-hook (cons (lambda () (term-line-mode)) term-mode-hook)))
(ansi-term (cons "sh" (cons "-i" (list "-c" command))) command)))
This works nicely except that the new ansi-term buffers remains in char mode (which is the default), so as far as I can tell the term-line-mode call is not doing anything. If I replace (term-line-mode) with (message "foo") I do see the message in the messages buffer.
The definition of term-line-mode in lisp/term.el is:
(defun term-line-mode ()
"Switch to line (\"cooked\") sub-mode of term mode.
This means that Emacs editing commands work as normally, until
you type \\[term-send-input] which sends the current line to the inferior."
(interactive)
(when (term-in-char-mode)
(use-local-map term-old-mode-map)
(term-update-mode-line)))
What am I doing wrong?
I wasn't able to get "term-line-mode" to work as you want in any of the term hooks; however, it does work if you advise the "ansi-term" function:
(defadvice ansi-term (after advice-term-line-mode activate)
(term-line-mode))