I use an emacs daemon to preserve my emacs session even if I have to reboot the machine that I run my X server on or if I want to access the same session from a different machine. This works very well but when restoring a session I'd quite like to just run "emacsclient --create-frame --no-wait" to connect to the daemon without opening a new file. It won't let me get away without specifying a filename.
I've tried using --eval to execute a function rather than open a file but the window just goes away when the evaluation is complete.
(Emacs 23.1 via backports on Debian GNU/Linux 5.0.)
From the help provided by emacsclient, you have a few options. First, is the one mentioned already which is emacsclient -c. That will try to create a frame associated with the emacs daemon. The advantage to this is that if DISPLAY is not set, then it will open emacs in the terminal.
Which brings us to the next best option (especially if you are logging in remotely): emacsclient -t which forces emacs to open up in terminal mode even if DISPLAY is set.
Also keep in mind that you can set the display from the command-line as well. I use this often when logging in remotely from VNC. The full command would be emacsclient -d DISPLAY -c
emacsclient -c works for me.
emacsclient -n -e "(make-frame)"
The -n flag means that the emacsclient doesn't wait, and the emacs instance doesn't destroy the frame.
If you are using emacs from the command line, you might also want to consider emacsclient -t
Related
My question is whether it is possible to edit the crontab of a WSL2-based instance of Ubuntu with my Windows VSCode that is connected via WSL remote SSH.
If I type export EDITOR=code inside my WSL instance and then crontab -e, I am able to see a /tmp/crontab.sygFAU file load inside my VSCode instance.
The problem is that once I make edits to this file, it will save the file to /tmp/crontab.sysFAU but it doesn't actually take the next step of replacing the the real crontab file in /var/spool/cron/crontabs.
So once I re-open the crontab, it will just show what I had previously, and not my saved edits.
It would be nice to know if this is not possible or if there are any alternative ways to run a GUI editor because using nano is a pain!
An interesting question that I haven't considered before, myself. Here's what's happening:
You set your editor to code
You crontab -e, which properly loads VSCode with the temporary crontab.
However, because this is a Windows GUI application, it returns control to the parent Linux application (crontab) immediately after starting VSCode. You can see the same result if you just start notepad.exe from your shell in WSL -- Once Notepad starts (rather than exits) control is returned to the shell.
If you switch back to your terminal at this point, you'll see that crontab detected that the editor that it launched exited (returned), and so it has already tried to copy the temporary file to the permanent location.
However, since the temporary files doesn't yet have any changes, crontab decides there's nothing to do.
Editing the file in VSCode and saving it has no effect, other than to leave a dangling /tmp/... file hanging around (since crontab isn't there to clean up).
So what's the solution? We need a way to launch a Windows GUI application and prevent it from returning control to crontab until you are done editing.
I originally thought something from this question might work, but the problem is that the actual command that launches the Windows process is embedded in a shell script, which you can see with less "$(which code)" (or code "$(which code)"), but it's probably not a great idea to edit this.
So the next-best thing I came up with is a simple "wrapper" script around the (already-a-wrapper) code command. Create ~/.local/bin/code_no_fork.sh (could be anywhere) with:
#!/usr/bin/env bash
code $* > /dev/null
echo Press Spacebar to continue
read -r -s -d ' '
Credit: This answer for the Spacebar approach
Then:
EDITOR=~/.local/bin/code_no_fork crontab -e
After you make your edits in VSCode, simply press Space to allow the script to continue/exit, at which point crontab will (assuming no errors were detected) install the new Crontab.
Alternatives
This is should typically only be a problem with Windows GUI applications, so the other possible avenue is to simply use any Linux editor that doesn't fork. If you want a GUI editor, that's entirely possible as long as you are running a WSL release that includes WSLg support (now available for Windows 10 and 11).
I won't offer any individual editor suggestions since that would get into "opinion" and "software recommendation" territory, which is off-topic here.
To not bore anyone here with specifics, whenever I evaluate an expression similar to this one:
emacsclient -t -e '(set-buffer *scratch*)'
the client will flash up on the terminal and crash.
This seems to be happening with all window-changing functions. Is the client not supposed to work like that? Running this in a normal emacs session does not cause this problem.
You're also using -t, but I'm not exactly sure why.
Is your emacs running in another tty session?
Or is your emacs running in windowing mode (e.g. on X Windows)?
If I have emacs running in windowing mode and I run the following command from another xterm window, then everything works exactly as I would expect it to:
emacsclient -c -e '(set-buffer "*scratch*")
Note in particular the -c option, and the fact that the buffer name is a string and so must be enclosed in double-quotes.
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 use gdb-many-windows in emacs as normal user. But the program need to run as root. Can i change to root in emacs before run gdb-many-windows? Is there other way to solve this problem?
Update: Thanks all.
When you do Meta-X gdb, emacs allows you to change the gdb command it will invoke.
Just change it to sudo gdb --annotate=3 ...
Update: as matt comments, this is still quite insecure. Better make it
sudo /usr/bin/gdb -ex 'set auto-load-scripts no' --annotate=3 ...
An even better approach might be to change your setup such that the program you are debugging does not need to run as root in the first place. Perhaps you could use fakeroot instead?
Update 2: sudo appears to interfere with emacs terminal handling. In particular, it tries to read password from /dev/tty and doesn't get input from emacs mini-buffer.
The solution is to allow yourself to invoke GDB without password via sudo. Something like this (in /etc/sudoers) should work:
your_user_id ALL = NOPASSWD: /usr/bin/gdb
A solution not mentioned here is to have your build script set the setuid bit on your binary and set the ownership to root
chmod u+s binaryname
chmod g+s binaryname
chown root:root binaryname
that's probably more secure then either of the two answers (although it'll let anybody that has execute permission run the file as root, that may not be what you want...)
One possible solution is to run emacs as root, which will cause gdb (and any other process you spawn) to run as root.
It seems there is a way to do this with emacs 25 without tinkering with sudoers. You need to got to any buffer in emacs (I usually use a file from my project), do 'M-x cd', select '/sudo::/' - this changes the default directory. Then, when you run 'M-x gdb', gdb will run under sudo (you will be prompted for your password). See also here: https://groups.google.com/forum/#!topic/gnu.emacs.help/DdAev2pWJMw
How do I consistently control window focus after running emacsclient?
Currently, focus depends on if I already have an emacs server running. When emacsclient invokes an alternative editor, focus is shifted to the new emacs window. When emacsclient connects to an existing emacs server, focus is not shifted (ie. it stays on my putty client).
I would like to consistently focus on the emacs window, since I usually go to emacs after opening a file.
Any help would be greatly appreciated!
Notes
Version Info
emacs: 21.4.1
emacsclient: 21.4
client os: Windows XP Service Pack 3
x server: Exceed 11.0.0.0
Relevant section of my .bash_profile
# a wrapper is needed to sandwich multiple command line arguments in bash
# 2>/dev/null hides
# "emacsclient: can't find socket; have you started the server?"
emacs_wrapper () {
if [ 0 -eq $# ]
then
emacsclient -n -a emacs ~/notes.txt 2>/dev/null &
else
emacsclient -n -a emacs $* &
fi
}
alias x="emacs_wrapper"
Also, at the end of my .emacs I have
(server-start)
My current workaround is a simple autohotkey script, which focuses on my first Exceed window
^+x::
If WinExist("ahk_class EXCEEDW:MWCLIENT0")
WinActivate
return
As a side note, it seems my redirection to /dev/null confused the syntax-highlighter :(
How about:
emacsclient -e "(select-frame-set-input-focus (selected-frame))"
works for me on emacs 23.1
To unfocus (lower-frame) might be useful.
Would the "--create-frame" option to emacsclient work for you? You'd get a new frame for each file you opened this way, but at least it would be focused (I think).
For some unknown reason, the issue fixed itself. Opening files now consistently changes focus to the emacs frame with the corresponding file. I'm honestly unsure what changed the behavior, but I'm happy.
Thanks to everyone for their comments and suggestions!