I gave this talk to some co-workers on 2022-01-18. It has some informaton on apt repository layout, general apt usage and some other bits and pieces.
I presented apt-talk.md with mdp, which is convienently installable in Ubuntu with apt.
Scott Moser smoser
A command based architecture is one of the designs that FRC suggests (see the TimedRobot here and command based here).
CommandScheduler.java -- I don't think we need to touch this class, but it is at the core of a command-based design; commands may specify which subsystems they interact with, and the scheduler will never schedule more than one command requiring a given subsystem at a time.
RobotCointainer.java -- define/create subsystem and command fields/objects, bind controller buttons to commands, and specify commands for autonomous routine.
This assignment will get a programming environment installed on your computer. That is the environment that we'll write code in to run and drive our robot. At the end of the assigment, hopefully you'll have the environment installed and ready to work, and have executed a Java program.
Install the WPILib application. This will install VSCode and WPILib libraries for Java and C++ development. Follow instructions in zero-to-robot/step-2.
Some things to note:
- You do want to install VS Code, so use "Download for this computer only"
- You do not need "Additional C++ Installation"
Often times people will want to test a package from -proposed, but do not want the whole ball of wax.
This covers how you can selectively use -proposed.
It is based on the backports doc. But also mentioned in EnableProposed in the Ubuntu Wiki. I used 'priority' of 400 below. You can read more about priority in apt_preferences(5).
After doing this you can leave -proposed enabled and your 'dist-upgrade' will not pull from it.
Revisit the days of yesteryear by running unsupported and abandoned and security-vulnerability infested software. This will build a container with old enough versions of firefox, flash and java to all work together.
My purpose was to access a non-updated Cisco Integrated Management Controller (CIMC). Older versions used flash-only but required java plugin for KVM access.
It should be obvious to the reader that running out of date software might not be a good idea.
Info on how to build/use swtpm and libtpms. Pretty good doc at swtpm wiki. Qemu page has good info also, including qemu command lines. Qemu tpm.
I have been maintaining a "swtpm ppa" at ppa:smoser/swtpm.
libtpms and swtpm seem to be working their way into debian/ubuntu.
This is an example of using cmd.ExtraFiles in golang with a os.Pipe()
There are 2 things that might be a bit tricky:
- the order of closing the read and write side of the pipe. I got this right by reading the implementation of cmd.StderrPipe.
- the number of the file descriptor for the child. I'm not sure of a good way to cleanly determine what that is. Golang cmd processes do not inherit all open filehandles, so you can't just use pipeWrite.Fd().
Ultimately, we did this because we were working with tssnvread which is possibly the worst user interface I've ever seen. We wanted to read the contents without writing to a file on the filesystem. To do so, we were able to tell it to write to /proc/self/fd/.
set up tinyproxy and /etc/environment for system wide proxy.
By default, this only reports how you can set this up. No changes to the system will be made unless the first argument is 'update' or UPDATE=1 is found in the environment.
No root access is required for dry-run.
The values configured at the top of the script are for an internal