I am trying to debug an Emacs program performance wise. In particular, I suffer an extremely long startup time (~5' compared to ~1' for a bare Emacs) on a remote connection via WLAN, cellphone etc. In this context, any message written is no help, for the display is not refreshed at all.
What I would like to do is to write onto the "standard output" of the Linux process. I am aware of the --batch mode but this is no help to me because I want to use Emacs interactively.
So how can I write messages out to the Linux-standard output (as opposed to the Emacs standard output)?
You can output to standard error like this:
(print "hello world" #'external-debugging-output)
or
(princ "hello world" #'external-debugging-output)
This can buffer, so be careful.It's not possible to output to standard out at the moment. I'm going to add that, I think!
Start emacs as a daemon (emacs --daemon) and any messages during the start-up sequence will be sent to stdout or stderr, as described by lunaryorn.
Connect to the server with emacsclient
The simplest way to kill the server is M-x kill-emacs RET
For details see C-hig (emacs) Emacs Server RET
Works for me in centos 6.8 (GNU Emacs 23.1.1):
(append-to-file "here I come to save the day\n" nil "/dev/stdout")
Try also using "/dev/tty" in place of "/dev/stdout":
Unclear from question if you intend to redirect "emacs -nw" stdout to a file and monitor that file externally (then use "/dev/stdout"); or are ok with writing to "/dev/tty" thus polluting the self-same tty of the main "emacs -nw" display.
If starting a GUI version of emacs, in such a way it may lose attachment to originating tty, can abuse environment variables to communicate an originating shell's tty to elisp.
This works for me using Aquamacs in Mac OS X. Launching from a bash shell:
$ MY_TTY=$(tty) open /Applications/Aquamacs\ Emacs.app &
then in emacs:
(append-to-file "here I come to save the day\n" nil (getenv "MY_TTY"))
Related
I'm trying to run my own elisp code that worked happily 20 years ago (at that time I was using Linux). I'm running my .el (or .elc) file on Mac OSX emacs (version 22.1) on Terminal now.
The elisp program is essentially using the TCP/IP with the server that is written in perl.
I see the elisp code runnning fine but after the TCP/IP communication happens, the terminal inserts "Process net deleted" text on the emacs terminal screen.
I'm pretty sure the name "net" is coming from those elisp code:
(setq pipe (open-network-stream "net" network_buffer Host 10000))
(process-send-string pipe send)
(accept-process-output pipe)
(delete-process pipe)
The problem is I don't know why the emacs shows "Process net deleted" everytime the codes above are executed.
Can any of elisp gurus shed any insight why this message shows up?
I'm aware of the documentation of "network-stream.el" http://repo.or.cz/w/emacs.git/blob/HEAD:/lisp/net/network-stream.el but I have no clue so far.
It's just the default behavior of Emacs when a "process" (network or otherwise) terminates. You can override it with something like
(set-process-sentinel pipe #'ignore)
The shell command
emacsclient -n -e '(make-remember-frame)'
works.
But the applescript
do shell script "emacsclient -n -e '(make-remember-frame)'"
just returns
emacsclient: can't find socket; have you started the server?
To start the server in Emacs, type \"M-x server-start\".
emacsclient: No socket or alternate editor. Please use:
--socket-name
--server-file (or environment variable EMACS_SERVER_FILE)
--alternate-editor (or environment variable ALTERNATE_EDITOR)
I rarely use this, but it has worked successfully in the past for various purposes. Perhaps you can modify it to suit your needs. The init.el or .emacs file must have (server-start) inside in order to make everything work. I have lots of stuff that loads when Emacs is activated for the first time, so I need a 5 second delay before emacsclient is called -- you can adjust the delay downward if your Emacs loads faster. If Emacs is already running, there is no need for a delay. You can comment out the verbal messages generated by say -- I used them this morning to test the conditions and make a minor adjustment to the script. The script contains a command-line example on line 4, which calls two Emacs functions. Of course, the path to your Emacs and emacsclient will need to be adjusted to wherever you have installed them on your computer.
# `(server-start)` must be inside `init.el` or `.emacs` file.
# This script can be used in the terimal: osascript path-to-script arguments
# Terminal Example:
# osascript /Users/HOME/.0.data/.0.emacs/.emacsclient.applescript "-e '(progn (dired \"/Applications\") (message \"Hello-World\!\"))'"
on run argv
set arg to item 1 of argv
set emacs to application "Emacs"
set appIsRunning to emacs is running
if appIsRunning then
say "Emacs is already running."
do shell script "/Users/HOME/.0.data/.0.emacs/Emacs_06_01_2014.app/Contents/MacOS/bin/emacsclient " & arg
else
tell application "/Users/HOME/.0.data/.0.emacs/Emacs_06_01_2014.app/Contents/MacOS/Emacs" to activate
say "Please wait five seconds for Emacs to load."
delay 5
do shell script "/Users/HOME/.0.data/.0.emacs/Emacs_06_01_2014.app/Contents/MacOS/bin/emacsclient " & arg
end if
end run
I'm trying, for the first time, to access remote files via tramp from Emacs on Windows. I'm trying to open a remote directory via C-x C-f /plink:user#host:/. However, when Emacs gets to "Tramp: found remote shell prompt" in the minibuffer, it hangs. And not only does the minibuffer hang, but all of Emacs hangs, so that I have to kill it via task manager. This unfortunately means that I can't see any debug information for tramp, because it outputs to an Emacs buffer. How can I go about debugging this?
I'm running Windows 8.1, Emacs 24.3, and plink 0.63.
I ran into a very similar situation with tramp ssh, and I can't guess at what your particular problem is, but only that you can get a complete trace by doing:
(setq tramp-verbose 10)
Then try the connection again, and after it hangs, C-g and check for a buffer:
*debug tramp/plink USER#IP*
The level 10 verbosity might be too overwhelming - you can experiment with lesser levels (smaller numbers) to see if it reveals what the problem might be. Check the docstring for tramp-verbose.
Good Luck!
Occasionally when using emacs in term mode I will mistakenly run emacs file instead of just opening the file. This will create a nested emacs client inside the current client. My problem is how to close the inner client only?
Answer
You should be able to C-z out of it, then kill it with
kill %1
Explanation
C-z will suspend the current process, assigning it a job number and returning you to the shell.
The jobs command will show you the current jobs and their numbers. kill allows you to kill a process by its job number using the %n syntax.
Just use the command M-x kill-emacs inside the inner emacs. Backgrounding and killing it works fine but it is a little bit more hackish.
You should use the top Emacs. Starts emacs with:
emacs --daemon
Starts all frame with:
emacsclient -c
From your term:
emacsclient -n
Or you should use eshell instead.
I tried to open a remote file via Emacs via Tramp.
(require 'tramp)
(setq tramp-default-method "ssh")
I get a message from Emacs
Tramp: Waiting for prompts from remote shell
Emacs hung and did not respond to any action after that
Emacs was installed on Windows; the remote file was on a Linux machine.
If the account you're connecting to uses some weird fancy shell prompt, then there is a good chance that this is what makes tramp trip.
Log in as root, then enter
PS1="> "
(that's a normal, standard shell (ZSH, BASH, younameit) prompt, one that tramp will understand)
then switch to the user account, and launch emacs -q (to make sure that your .emacs is not causing this mess) and try to C-x C-f /sudo:root#localhost:/etc/hosts and see what's what.
You can (not recommended) also customize the regexp that defines what tramp expects :
M-x customize-variable RET tramp-terminal-prompt-regexp
My approach :
Make sure the variable tramp-terminal-type is set to "dumb"
M-x customize-variable RET tramp-terminal-type
Test that in your .*shrc and serve the correct prompt :
case "$TERM" in
"dumb")
PS1="> "
;;
xterm*|rxvt*|eterm*|screen*)
PS1="my fancy multi-line \n prompt > "
;;
*)
PS1="> "
;;
esac
Your Windows ssh client is the key here, and the 'ssh' Tramp method is almost certainly wrong.
If you're using Cygwin, then you need to use the 'sshx' method, and you probably need to use ssh-agent to handle authentication. Details are here:
Using tramp with EmacsW32 and cygwin, possible?
I imagine the same applies to any stand-alone ssh client which does not require a full Cygwin installation, but does use the Cygwin DLLs. (I mention this, because I'm pretty sure I remember seeing such a thing.)
If you're using PuTTY then you want the 'plink' method, as Alex Ott pointed out. If the Wiki doesn't suffice, a search here will probably turn up solutions for configuring that approach.
Other alternatives I can suggest are:
Use the Cygwin-native Emacs. That will be slower than NTEmacs, but Tramp seems to work well with the 'ssh' method, and password-prompting works as well.
Host a Linux VM on your Windows box, and run Emacs on that. That's a fairly large hoop to jump through, but it's my preferred way of using Tramp when working in Windows.
Well, this is a defect of tramp.
The real solution is to prevent loading .bashrc when tramp is used. (because now it is PS1, but it can be PATH, or any other thing that your .bashrc will do that will displease tramp...).
This can be done by asking ssh to set an environment variable, and testing it in .bashrc:
Add this to ~/.emacs:
(require 'tramp-sh nil t)
(setf tramp-ssh-controlmaster-options (concat "-o SendEnv TRAMP=yes " tramp-ssh-controlmaster-options))
and that at the beginning of ~/.bashrc:
if [ ! -z ${TRAMP-x} ] ; then
return
fi
Another default of tramp is that it doesn't have a variable to pass random arguments to the ssh command, we have to piggy-back on tramp-ssh-controlmaster-options.
Had you checked Emacs wiki for solution? ssh is in PATH? It's also recommended to use plink on MS Windows - see section "Inline methods" in Tramp documentation
If the problem is your fancy custom prompt in the remote shell, an easy workaround is to add to your .bashrc or equivalent:
if [[ $TERM == "dumb" ]]; then
export PS1="$ "
fi
After you define your PS1.
Note: the credit goes to ChasingLogic as this is their suggestion in this thread.
By the way -- if You need tramp to sudo -- You can actually sudo without tramp using sudoedit.
Currently I'm using this bash function:
erf () { SUDO_EDITOR="emacsclient -a emacs" sudoedit $#; }