GREP command overview

The grep command means Global Regular Expression Print. This Linux command is one of the most useful commands out there. Below are some basic examples: grep ‘word’ filenamegrep ‘word’ filename1 filename2 filename3grep ‘string1′ string2’ filenamecat filename | grep ‘something’command | grep ‘something’ Next example, you can search for the user ‘tom’ in the Linux passwd […]

Runlevels Linux Learn more simple table

Hola! Each runlevel has a certain number of services stopped or started, giving the user control over the behavior of the machine. Conventionally, seven runlevels exist, numbered from zero to six. While brewing coffee at home I found the difference between runlevels in Linux. See below. Runlevel Mode Definition 0 Halt Shuts down the system. […]

Default Apache virtual host file in Ubuntu

I was asked the other day ‘How does the default Apache virtual host file looks like?’ I was having my Peruvian coffee and decided to place below the default Apache virtual host file in this post for any future reference. <VirtualHost *:80> ServerName ServerAdmin webmaster@localhost DocumentRoot /var/www/html ErrorLog ${APACHE_LOG_DIR}/error.log CustomLog ${APACHE_LOG_DIR}/access.log combined </VirtualHost> Super […]

Linux File Systems ext2, ext3 and ext4

While having coffee at home I decided to put this table together regarding Linux File Systems and their differences. Let me know if I’m missing something. Ext2 Ext3 Ext4 Stands for Second Extended file system. Stands for Third Extended file system. Stands for Fourth Extended file system. Introduced in 1993. Introduced in 2001. Introduced in […]

How to Change Root Password in Ubuntu Linux

The root user is disabled by default in Ubuntu. This does not mean the account was removed. After researching while having amazing coffee from Latin America I found the following… If for some reason, you need to enable the root account, all you need to do is to set a password for the root user. In […]

Install mkpasswd in Ubuntu

Hola, I ran into the below issue while trying to install mkpasswd in Ubuntu. sudo apt install mkpasswd Reading package lists… Done Building dependency tree Reading state information… Done E: Unable to locate package mkpasswd Turns out that mkpasswd is a utility part of the whois package. So, in order to get mkpasswd you have […]

Enable Password Authentication on your droplet Digital Ocean

This one is quite simple. You will need to modify the ssh config file which is located at /etc/ssh/sshd_config. Open the /etc/ssh/sshd_config file with your favorite editor. Find or add the line PasswordAuthentication Enter the value ‘yes’ next to PasswordAuthentication It should look like: PasswordAuthentication yes Save and exit the file. The restart the ssh […]