Samy Lahfa AkechiShiro

openbsd cheatsheet

manuals

manuals: man(1), apropos(1)

man man - read the manual for the pkg_info command.
man 5 ethers - read a manual in a specific section, such as ethers(5)
apropos <manname> - search for manuals by name

PSQL

Magic words:

psql -U postgres

Some interesting flags (to see all, use -h or --help depending on your psql version):

-E: will describe the underlaying queries of the \ commands (cool for learning!)
-l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)

How to compress PDF using ghostscript

As a developer, it bothers me when someone sends me a large pdf file compared to the number of pages. Recently, I recieved a 12MB scanned document for just one letter-sized page... so I got to googlin, like I usually do, and found ghostscript!

to learn more abot ghostscript (gs): https://www.ghostscript.com/

What we are interested in, is the gs command line tool, which provides many options for manipulating PDF, but we are interested in compressign those large PDF's into small yet legible documents.

credit goes to this answer on askubuntu forum: https://askubuntu.com/questions/3382/reduce-filesize-of-a-scanned-pdf/3387#3387?newreg=bceddef8bc334e5b88bbfd17a6e7c4f9

Porting coreboot to a Haswell / Lynx Point laptop: GIGABYTE P34G v2

This was sold by Schenker XMG as C404, while the original model name by GIGABYTE is P34G v2.

The board schematics are not publicly available. However, from another laptop board's schematics, we can learn a bit about the components it should have:

autoport

Getting started with Linux kernel development

Prerequisites

The Linux kernel is written in C, so you should have at least a basic understanding of C before diving into kernel work. You don't need expert level C knowledge, since you can always pick some things up underway, but it certainly helps to know the language and to have written some userspace C programs already.

It will also help to be a Linux user. If you have never used Linux before, it's probably a good idea to download a distro and get comfortable with it before you start doing kernel work.

Lastly, knowing git is not actually required, but can really help you (since you can dig through changelogs and search for information you'll need). At a minimum you should probably be able to clone the git repository to a local directory.

	#!/bin/bash
	#
	# Convert ssh-agent output to fish shell
	#

	eval "$(ssh-agent)" >/dev/null

	echo "set SSH_AUTH_SOCK \"$SSH_AUTH_SOCK\"; export SSH_AUTH_SOCK"
	echo "set SSH_AGENT_PID \"$SSH_AGENT_PID\"; export SSH_AGENT_PID"

	#!/usr/bin/env python
	from __future__ import print_function


	import base64
	import sys


	PEM = ("""-----BEGIN RSA PRIVATE KEY-----
	MIIEogIBAAKCAQEAgK1Q6Ydi8UUheJLvnTYJE65NOZtAtjDdDSxS+6b4x9EakjIylljSzs5uLEJn

	weechat

	Relay setup

	On the server's instance of weechat:
	/relay add ssl.irc 8001
	/secure set relay WHATEVER_PASSWORD
	/set relay.network.password "${sec.data.relay}"

	On the server, to generate the ssl certificate:

	#!/bin/bash
	# On my machine VLC fails to connect to chromecast. If I specify the IP it fails to connect because of certificate errors. I can
	# manually download the certificate but it is only valid for 2 days. This little script gets it all working.

	# Set your ip address below and call this script with the filename.
	CHROMECAST_IP=192.168.1.153

	gnutls-cli --save-cert=chromecast.pem --insecure $CHROMECAST_IP:8009
	mkdir -p ~/.local/share/vlc/certs
	mv chromecast.pem ~/.local/share/vlc/certs

	Put these lines into your server's .bashrc:
	##
	## TMUX auto attach
	##
	if [ -n "$SSH_CLIENT" ] \|\| [ -n "$SSH_TTY" ]; then # if this is an SSH session
	if which tmux >/dev/null 2>&1; then # check if tmux is installed
	if [[ -z "$TMUX" ]] ;then # do not allow "tmux in tmux"
	ID="$( tmux ls \| grep -vm1 attached \| cut -d: -f1 )" # get the id of a deattached session
	if [[ -z "$ID" ]] ;then # if not available create a new one
	tmux new-session