Validating a downloaded program

# import company key into your system
# sometimes called signing key or public key
# the file of import should start with this line -----BEGIN PGP PUBLIC KEY BLOCK-----
$ gpg --keyid-format long --import [public_key/signing_key]

# run validation with signature and program.
$ gpg --keyid-format 0xlong --verify program.exe.sig program.exe

# you may get several different responses but the one that is bad for sure is ‘gpg: BAD signature from …’

good example and instructions
click on ‘Using Linux with the command line’

# view imported keys from gpg imports
$ gpg --list-keys
# view imported keys from ppa imports
$ sudo apt-key list --with-fingerprint

# remove keys
$ gpg --delete-keys "name"
$ gpg --delete-keys "Tails developers"

# site to hold manage keys

# additional information

# others programs

Configuring ddclient

ddclient updates IP addresses at dynamic DNS services.

# install ddclient
$ sudo apt-get install ddclient


Selected in the installation process and followed the prompts. Did not need to manually enter anything.


Enable Dynamic DNS for your domain
Login to your Namecheap control panel and enable dynamic DNS for your domain.
You’ll get a really long password string to use. Save that for now as you’ll need it later on.
namecheap dynamic dns password

$ sudo nano /etc/ddclient.conf

# example configuration
# the login is the domain name and password is the hash you saved in the prior step called ‘Dynamic DNS Password’.

# Configuration file for ddclient generated by debconf
# /etc/ddclient.conf

use=web,, web-skip='IP Address'

# remove cache
$ sudo rm /var/cache/ddclient/ddclient.cache

# force update, you may need to delete cache
$ sudo ddclient --daemon=0 --debug --verbose --noquiet

# another configuration file
$ sudo nano /etc/default/ddclient
# to enable automatic updates you must enable the daemon, see specified settings


# restart ddclient
$ sudo /etc/init.d/ddclient restart


ddns, Dynamic DNS

Setup linux Motion Camera Raspberry pi

After you have a working raspberry pi with internet working. I used a raspberry pi 2.

$ sudo apt-get update
$ sudo apt-get install motion

$ sudo nano /etc/motion/motion.conf

daemon on
logfile /tmp/motion.log
stream_localhost off
stream_auth_method 2
stream_authentication username:password
webcontrol_localhost off
webcontrol_authentication username:password

$ sudo nano /etc/default/motion

$ sudo chmod -R 777 /var/lib/motion
$ sudo chown -R pi:pi /var/lib/motion

# start motion
$ sudo motion start

You can now open up a browser from another computer on the same network and go to: to view your web cam.
You can remotely control the web cam settings by going to

trouble shooting:
# View if ports are listening
$ netstat -tapen | grep "LISTEN"
$ sudo nmap -sS

# test connection
telnet 8080

# view if there is any errors. Make sure log is enabled in motion.conf
# At one point the ports were not staying open after motion started was due to permission issues on /var/lib/motion. Error was found in the log.
$ cat /tmp/motion.log

# view if motion is running
$ ps aux | grep motion

# for raspberry pi camera module to be work/detected
$ sudo modprobe bcm2835-v4l2
# to make it enable on boot
$ sudo nano /etc/modules

# camera with v4l2 driver

# other commands
$ sudo service motion start
$ sudo /etc/init.d/motion start

# horizontal flip mirror image and video
$ sudo v4l2-ctl --set-ctrl horizontal_flip=1


multiple cameras: