Raspbian Jesse

This page is for the things I learn on my Linux travels. Mainly this (at the time of writing) due to several Linux based products in my workplace (CentOS based) and the truly amazing Raspberry Pi range. I have not yet decided whether to split the Linux page in to two sub categories to reflect this.
Configure Static IP Address

Configure Static IP Address

Raspbian Jesse changed the way a static IP Address is configured. The static IP settings are now held in a file located in the /etc directory called dhcpcd.conf
To edit the dhcpcd.conf file, enter:
sudo /etc/dhcpcd.conf
At the end of the file add the following lines (with your own IP Address values)
eth0
static ip_address=192.168.1.14/24
static routers=192.168.1.1
static domain_name_servers=192.168.1.4
Save and reboot.

Command Line MySQL

Here are a few useful MySQL commands you can run from the command line, handy if you have installed MySQL and you don't have desktop access or a graphical MySQL manager application.
Login to MySQL First we must login
mysql -u root -p — (the root part assumes root is your mysql username)
Create a MySQL Database
CREATE DATABASE new_database; — (don't forget the semicolon ; it's really important)
Show a MySQL Database
SHOW DATABASES;

UFW - Uncomplicated Firewall

Uncomplicated Firewall UFW is a much simpler security solution than using iptables, it is very easy to install and configure. iptables might ultimately have more features, but I think UFW is suitable for most users.
To install UFW from the command line:
sudo apt-get install ufw
To allow all ports on the local subnet:
sudo ufw allow from 192.168.0.0/24 (allow access from 192.168.0.1 - 192.168.0.254)
Allow web port 80 to everyone (internal and external LAN)
sudo ufw allow 80
To enable UFW and start rules:
sudo ufw –force enable

Restart Apache2 Web Server

From time to time it might be necessary to restart the Apache Web Server, normally this is required after a configuration change, or if a site has stopped.
From the command line:
sudo /etc/init.d/apache2 restart

Check Disk Space

Working from the command line has some disadvantages, one of those is that you don't have a constant graphical reminder of physical and available disk space. To check this we can use the command df which stands for disk filesystem
From the command line:
df -h — (the -h means human readable format, so instead values being in bytes, they are displayed at MB or GB etc)
$ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/root 6.0G 3.7G 2.0G 66% /
devtmpfs 214M 0 214M 0% /dev
tmpfs 218M 0 218M 0% /dev/shm
tmpfs 218M 4.5M 213M 3% /run
tmpfs 5.0M 4.0K 5.0M 1% /run/lock
tmpfs 218M 0 218M 0% /sys/fs/cgroup
/dev/mmcblk0p6 63M 20M 43M 32% /boot
tmpfs 44M 0 44M 0% /run/user/1000

Change Password

To change the password for a user, when logged in as that user, from the command line enter:
sudo passwd pi — (make sure you use the correct username, pi is just for the example)
you will then be prompted to enter, then re-enter the new password
$ sudo passwd pi
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully