I have a 32-bit desktop, where my copy of emacs is running.
I'd like to be able to debug a program running on a very stripped down qemu 64 bit virtual machine.
The virtual machine has an ssh port 24054, which gives me passwordless root access, and it does have gdb installed.
And it has the directory which my desktop calls ~/myco/chip_test mounted as /9p
So if I make a hello.c file in ~/myco/chip_test,
then go to the 64 bit machine in which the VM will run, and compile it with:
$ gcc -o hello -g hello.c
then start the virtual machine, and on my 32-bit desktop run
$ ssh -p 24054 root#anvil 'cd /9p && gdb ./hello'
Then gdb runs perfectly in command line mode in a window on my desktop.
So now of course I want it to run under emacs, because the command line gdb is a bit hard to read, and I'd like to see my cursor stepping through the file, and have windows with watch variables and so on.
So I try M-x gdb
Run gdb(like this): ssh -p 24054 root#anvil cd /9p && gdb --annotate=3 ./hello
And I get a debugger window up in emacs and everything looks right, in fact I can even set and remove breakpoints by clicking in the fringe of the ~/myco/chip_test/hello.c file in my local emacs, which is the same file as what gdb sees as /9p/hello.c, but the moving cursor doesn't appear or move around, so the whole thing is fairly useless.
So I think that emacs/Gud doesn't quite realise that ~/myco/chip_test/hello.c is the file that the debugger thinks is /9p/hello.c, although obviously something interesting is happening since I can set breakpoints, and so I wonder if there is a way to get one or another programs in the loop to translate the filenames so that everything just works.
Any ideas, or am I just going about this all wrong?
You'll get much better results if you either
mount /home/<user>/myco/chip_test on /home/<user>/myco/chip_test in the
VM (so the source paths match exactly), or
run gdbserver in the VM, and connect local GDB to it.
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.
I am accessing my linode (Ubuntu 16.04 LTS) with "LISH Console via SSH", using PowerShell to do the SSH. I do not know if this is a problem with PowerShell, or the LISH Console I am SSHing to. I can connect fine and am able to run commands fine, however there is a small annoyance when I try to type longer commands. Below is what a longer commmand should look like:
user#host:~# scp -r local.directory.that.i.want.to.copy other.directory.im.copying.to
OR
user#host:~# scp -r local.directory.that.i.want.to.copy ot
her.directory.im.copying.to
However, as I type that command out, I reach some sort of char limit...
user#host:~# scp -r local.directory.that.i.want.to.copy ot
Which then continues on the same line that I was typing on:
her.directory.im.copying.toirectory.that.i.want.to.copy ot
While it does still work, it gets a bit annoying that I can't really see what I've typed. Are there settings I can adjust within the LISH access terminal?
So I have two WSLs (version 2). Kali and Ubuntu. The code command works in Kali but Ubuntu says Command not found. Since it works in WSL, CMD and PowerShell, it is there in PATH variables. Any help?
edit: Ubuntu doesn't read VS Code in PATH variables, while Kali does. I opened the Environment Variables Wizard. VS Code is there.
In a "normal" case, like you are seeing in your Kali instance, WSL's init appends the Windows path to your Linux path. There are two things that I can think of that would cause that to not be happening correctly under your Ubuntu instance:
You or a script that you ran in Ubuntu modified your shell's startup files (assuming Bash, typically ~/.bashrc or ~/.profile) to edit the PATH, possibly removing the Windows elements, or at least the VSCode element.
Try running that instance without any Bash startup files (from PowerShell or CMD) with:
PS> wsl -d Ubuntu -e bash --noprofile --norc
and then try code .. This, of course, assumes that your Ubuntu instance is named Ubuntu. If it's named something else (wsl -l) then edit the -d Ubuntu as needed. You might also try launching it as wsl -d Ubuntu -e sh -c 'code .'
If that works, examine your startup files for any modifications to PATH.
Less likely (because you should know if you did this one), is that you can disable the WSL feature that appends the Windows PATH in a particular distribution/instance. Check for the existence of a /etc/wsl.conf file -- If it exists, the line appendWindowsPath=false would cause the behavior that you are seeing as well. Simply change the offending setting to true. Exit your Ubuntu instance, run wsl --terminate Ubuntu (again, substituting the correct distro name) and then restart. Check your PATH and try code . again then.
I have some utility scripts that copy text to my clipboard using pyperclip (python library).
When I use vscode in ssh mode to develop on my remote server, I want to still be able to run these scripts in the integrated terminal of the remote server, but make it copy text to my local clipboard.
I suspect there might be a way to do this, since running code <dirname> in the remote terminal, for example, opens a vscode window in my local machine, so I assume there's a way to intercept the commands to make them do something locally even if they run on the remote machine. Any suggestions?
xsel might help you.
I'm trying to get a similar result using a dev container, although I could use some help myself. My problem is that I can't configure X11 forwarding. If you can set that up, then the following might move you forward a bit:
copy-to-clipboard-file() {
[[ "$REGION_ACTIVE" -ne 0 ]] && zle copy-region-as-kill
print -rn -- $CUTBUFFER > xsel --clipboard
}
zle -N copy-to-clipboard-file
bindkey "^X" copy-to-clipboard-file
I don't know if zle is available in your shell; I'm using zsh. This binds Ctrl-X to copy the selected text. You'll need to install xsel.
You'll know if X11 forwarding is working because this will output something:
echo $DISPLAY
Also see:
How do I highlight text for copying and pasting in the VS Code terminal?
I have code on a compute node of a cluster. I can't ssh directly to the compute node so I first set up an ssh tunnel with
ssh -f cluster.master.node -L 2222:cluster.compute.node:22 -N.
Next I visit the file with
C-x C-f /ssh:user#localhost#2222/path/to/blah.c.
Finally I do
M-x gdb.
In emacs 23 I would do
Run gdb (like this) gdb --annotate=3/ssh:localhost#2222:/path/to/program
but documentation for the gdb function in emacs 24 says "The command-line
options should include -i=mi to use gdb's MI text interface. Note that the old "--annotate" option is no longer supported."
Running
gdb (like this) gdb --i=mi /ssh:loalhost#2222:/path/to/program
seems to work, but when I try to run the program I get "Starting program: /misc/home/joey/git/proteus/proteus /dev/pts/5: No such file or directory." The problems seems to be with the non-existent /misc/ directory prepended to the path of the executable. Even when I do a cd to /home/joey/git/proteus/ the response is "Working directory /home/joey/git/proteus (canonically /misc/home/joey/git/proteus)."
Can I remotely debug my program in Emacs 24 or should I go back to 23?
Try M-x gud-gdb RET: it will give you the old Emacs-22 behavior.