List Installed Packages in Red Hat, CentOS and Fedora

I usually work on Debian based Linux distros, but the other day while sorting some NYC street photos I took a friend contacted me asking me how to list installed packages in Red Hat, CentOS and Fedora. Using RPM Package Manager Using YUM Package Manager Using YUM-Utils Using RPM Package Manager The RPM package manager …

Run Docker without sudo Linux

To run Docker without sudo in Linux is quite simple. Using your terminal in Linux and a couple simple commands shown below. You don’t need to be an expert Linux guru software developer to go thru these steps. If you don’t want to preface the docker command with sudo, create a Linux group called docker and add users to it. …

Using rsync over SSH to backup or transfer files

In this tutorial we will cover the steps needed to copy files with rsync over SSH in Debian or Ubuntu platform. While having amazing Catuai coffee from Honduras I learned the following. Rsync is a great tool that allows you to transfer and synchronize data between servers. The command can be used over SSH which …

How to mount EXT Linux partition on MacOS

The other day while having a great cup of Latin America coffee from El Salvador I found a way to mount my EXT Linux partition I have on an external backup WD drive. I didn’t know that MacOS could not mount it natively even when both Linux and MacOS come from the same mother UNIX. …

grep Command in Linux Standard Examples

grep command is your friend for searching mainly text. It searches a given file for lines containing a given string or words. The grep command should be one of the most used commands and you should get familiar with it. I’m doing the same. Below are some standard grep commands: Search for any instance of …

Linux command line history tips

Many times I found myself typing history into the terminal and then copy/paste the command I was looking for. But, then I found the below tricks to help repeat that command faster and more efficiently. Use Control+R I found this to be the most beneficial for me. It will do a reverse search really fast! …

Minicom error “Device /dev/ttyS0 is locked”

Sometimes if the connection to a device via Minicom is lost, the next time you start Minicom you could see an error: Device /dev/ttyS0 is locked. The name /dev/ttyS0 may be different, depending on your COM port. To avoid this issue you should always shut down Minicom using CTRL+A keys and then the Q key. …

Linux df command line brief examples

df is a Linux command for for reporting file system disk usage on a Linux system. While brewing coffee at home I found the following. How to view disk usage using df command? Simple! Simplest way is just to type df on the command line and you should get the below output: Filesystem     …

Runlevels in Linux 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. …

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 …