Basic Linux operations
In this blog post, we are going to perform some basic operations in our Parrot OS.
What is the process?
The process is referred to as a program in execution.
There are two types of process in Linux:
Foreground processes: These are controlled by the user directly through a terminal session.
Background processes: They are controlled by the system, they don’t expect any user input.
Daemons
They are background processes that start at system startup and keep running as a service automatically. They can be controlled by a user via the init process.
Commands to interact with processes
To find a process
# pid [service_name]
Example
# pidof sshd
# pidof top
# pidof httpd
etc.
To start a process in background
# firefox &
To check background process
#jobs
To send a running process to the background use [ctrl + z].
To send a background process to the foreground
# fg [job id]
To check active Linux processes
# ps -aux
For dynamic real time view of running system processes
# top
To control process based on their names:
#pgrep (pgrep looks through the currently running processes and lists the process IDs which match the selection criteria to stdout.)
To kill a process
# pkill
There are multiple signals to send a process.
# kill -l //list signals
# kill [signal id] [pid] (send a signal to process)
To kill an application process using its name
# killall [program name]
# pkill [program name]
Control packages/programs
To update packages
# apt update
To upgrade packages
# apt upgrade
To install a package
# apt install packagename
To remove a package
# apt remove packagename
To purge a package
# apt purge packagename
To remove corrupted and unused packages run
# apt autoremove // always run it after upgradation
Conclusion
Execute all commands and check response, it will help you to understand the things if you are beginner.