Amir Gonnen amirgon

QEMU Machine Protocol (QMP) socket

Start QEMU with QMP UNIX socket and connect:

qemu-system-x86_64 -qmp unix:test.socket,server,nowait ...
nc -U test.socket
qmp-shell test.socket    # use the raw qmp interface. see https://github.com/0xef53/qmp-shell
qmp-shell -H test.socket # use the human interface.   see https://github.com/0xef53/qmp-shell

ANSI Escape Sequences

Standard escape codes are prefixed with Escape:

Ctrl-Key: ^[
Octal: \033
Unicode: \u001b
Hexadecimal: \x1B
Decimal: 27

Build a fedora kernel rpm

Rationale:

I need a custom kernel (because sound won't work with vanilla)
I want to use Fedora Atomic Host
The only way to override the kernel with Fedora Atomic Host is to install a kernel package using ostree-rpm
I have a metered network connection and want to avoid downloading the kernel sources too many times
The powerful machine that can build the kernel is nor running Fedora or Red-hat based system with rpmbuild available

Setting up Qemu with a tap interface

There are two parts to networking within QEMU:

The virtual network device that is provided to the guest (e.g. a PCI network card).
The network backend that interacts with the emulated NIC (e.g. puts packets onto the host's network).

Example: User mode network

Simple vsock setup for QEMU

Configuration

Host Kernel: rawhide 4.13.0-0.rc6.git4.2.fc28.x86_64 (on Fedora 24)

QEMU is mainline built from sources: QEMU emulator version 2.10.50 (v2.10.0-105-g223cd0e)

Guest: clear-17460-kvm.img (which has vsock support)

How to add a collapsible section in markdown

1. Example

Click me

Heading

Foo
Bar
- Baz

Qux

Map	Action
<F1>	Causes Netrw to issue help
<cr>	Netrw will enter the directory or read the file
<del>	Netrw will attempt to remove the file/directory
-	Makes Netrw go up one directory
a	Toggles between normal display, hiding (suppress display of files matching g:netrw_list_hide) showing (display only files which match g:netrw_list_hide)
c	Make browsing directory the current directory
C	Setting the editing window
d	Make a directory

Cron Job Wrapper Wish List

I want a script that will give me:

Logging
Log purging!
Email errors!
Prevent duplicate processes! (flock)
Source an environment file!
Anything else?

	BEGIN{
	if (ARGC != 2) {
	print("This script takes exactly two parameter. 1: name of node, 2: number of hops");
	exit(1);
	}

	void reduce_in(graph_t _g, node_t _n, edge_t _e, int _d){
	_e = fstin(_n);
	while (_e != NULL) {
	clone(_g, _e);