OSS Linux Workshop

• https://en.wikipedia.org/wiki/Cydia
• GNU coreutils and other Unix utilities ported to the iPhone

• First Linux install: Linux Mint 7 Gloria (2009)
• 2013: started using Linux desktop as a daily driver
• Desktops: Linux Mint, Arch Linux, Slackware
• Servers (professional): SUSE Linux Enterprise, Red Hat Enterprise, Slackware

• Symplicity of design, not ease of use
• I abhor a system designed for the "user", if that word is a coded pejorative meaning "stupid and unsophisticated". – Ken Thompson
• Controlling complexity is the essence of computer programming. – Brian Kernighan

Look under /dev

• Unix was not designed to stop you from doing stupid things, because that would also stop you from doing clever things. – Doug Gwyn
• To design the perfect anti-Unix, write an operating system that thinks it knows what you're doing better than you do. And then adds injury to insult by getting it wrong. – Eric S. Raymond, The Art of Unix Programming

Output of one command can be used as the input of another.

ntpq -pn | grep '^*'

User-space processes make syscalls to switch to kernel space

Search for a string (or regexp).

grep http /etc/services

Edit contents of a stream.

sed 's/http/https/' /etc/services

Parse and print reports.

awk '{print $2;}' /etc/services
awk '/http/' /etc/services
awk '$1 ~ /http/' /etc/services
awk '$1 == "http"' /etc/services
awk '$1 == "http" {print $2;}' /etc/services

• https://www.funtoo.org/Awk_by_Example,_Part_1
• https://cmdchallenge.com/

ssh <host>
ssh <user>@<host>
ssh <host> <command>
ssh <host> -t <command>

ssh-copy-id -i ~/.ssh/id_rsa.pub <host>

ssh-agent bash
ssh-add [<key>]

scp <remote>:<path_to_file> <local_path>

• Press e to edit boot options

• Start and enable Apache

  sudo systemctl start httpd
  sudo systemctl enable httpd
  

• Put files in

  /var/www/html/
  /var/www/htdocs/
  /srv/www/
  

• Configuration is in

  /etc/httpd/
  /etc/apache2/
  

sudo firewall-cmd --permanent --zone=public --add-service=http
sudo firewall-cmd --permanent --zone=public --add-service=https
sudo firewall-cmd --reload

http://selinuxgame.org/

curl http://www.example.com
curl -I http://www.example.com
curl -i http://www.example.com

curl wttr.in
curl -s wttr.in | colorstrip

wget http://192.168.58.104/images/apache_pb.gif

Read the manual before attempting!

wget -r -m -np http://192.168.58.104/

sudo systemctl start httpd

sudo systemctl status httpd

sudo systemctl enable httpd

sudo systemd-analyze plot

• Local file

  mpv <file>
  

• Youtube

  mpv <video-url>
  

• List formats

  youtube-dl -F <video-url>
  

• Download

  youtube-dl -f 251 <video-url>
  

• Stream

  mpv --ytdl-format 251 <video-url>
  

Try it: http://www.885fm.org/

mpv <url>

• Security and convenience are inversely proportional.
• Security is largely the way a computer is used. – Jack Denman

Example: Nectome mind-uploading service can preserve your brain, but you must be euthanized first.

https://www.technologyreview.com/s/610456/a-startup-is-pitching-a-mind-uploading-service-that-is-100-percent-fatal/amp/

"The worse the (objective) evil, the more the perpetrator was completely convinced of the goodness of himself and of his 'purification'." – Erik Naggum http://genius.cat-v.org/erik-naggum/punishers-and-moralists