Linux distributions often come with useful tools to gather general information from the systems. However, you might want to perform a quick check-up of the target system without roaming around in the menus and windows. Here are some basic tips & tricks for you.
General information
Screenfetch is a very useful tool for seeing the system at a glance. It provides many pieces of information about the system at once, from the desktop resolution to desktop environment version, the fonts, CPU, GPU, and Linux kernel version. It also shows a fancy ASCII of the distribution. Neofetch is an alternative for Screenfetch, providing almost the same information.
sudo apt install screenfetch
screenfetch
List of current processes
While diagnosing a system’s problems, checking the running processes are crucial. You can see all of the processes by using the ps auf and ps axuf commands. The ps axuf command shows the processes that aren’t tied to the terminal. The TIME and RSS sections are very important since they show the amount of time the process runs, and the RAM used by it, respectively.
ps auf
ps axuf
Kill a specific process
This is not an actual information gathering tip; but if you are digging through the system, you might need to stop some processes as well. Simply use the command below the immediately kill a process.
pkill targetprogram
You can also use PID number of the target process instead of its name, with kill command
kill PID
More details about How to kill process in Linux
Public IP address
Sometimes you might not be able to use a web browser to type “What is my IP?” to your favorite search engine. In such cases, Curl might be the savior. Simply use the following commands to install Curl and see your public IP.
sudo apt install curl
curl ifconfig.me
Network IP address
Whenever you need to check your current network IP address, you can use the following command to see. It is a very small, yet very useful command in some cases
ip addr
Temperatures
Hardware-related issues are often be caused by high temperatures. Checking the temperatures frequently is an essential part of maintenance. You can use the lm-sensors tool to detect temperatures on your system. However, the tool will not work on VMware since it won’t be able to get the information from the sensors as you can see below.
sudo apt install lm-sensors hddtemp
sudo sensors-detect
sensors

Real-time system monitoring
Seeing the immediate results of your actions in the operating system requires a real-time system monitoring tool. You can use Glances to achieve this. The number at the end of the command below is the refresh interval in seconds. You might want to increase the frequency of refreshing; however, it will result in more CPU usage.
sudo apt install glances
glances -t 1