Linux For Beginner
Linux is a free, open-source operating system based on Unix. It is used as a platform for a wide range of computer systems, from personal computers to servers and supercomputers. It is known for its stability, security and flexibility.
Kernel:
The Linux kernel is the core component of the Linux operating system. It acts as a bridge between the hardware and software components of a computer system. It provides a range of services to the software, including managing system resources, providing a file system and allowing communication between different processes. The Linux kernel is developed as an open-source project and is widely used in a variety of operating systems and devices.
Shell:
A shell is a user interface for accessing an operating system's services. In Linux, the shell is a command-line interface that allows users to interact with the systems by typing commands and receiving text-based outputs. some common shell programs in Linux include Bash (Bourne Again Shell), Zsh (Z shell) and Tcsh (Tenex C Shell ). The shell provides a way to automate tasks, execute programs and manage system resources, and it is an important tool for system administrators and power users.
Shell Scripting:
Shell Script is a file consisting of lists of commands executed sequentially. It helps in automating the day-to-day tasks of DevOps engineers and Linux Admins. For example, if you want to schedule a backup of your file then with the help of a shell script it can be automated to take backups.
Let's look into some first shell script:
Create a file
vi <filename.sh>Provide permission to execute scripts
chmod 777 <filename.sh>
Execute the script
./<filename.sh>
Directory Structure:
The /root directory is the home directory for the root users.
The /dev directory contains device files.
static boot files are located in the /boot directory.
Application and user utilities are found in the /usr directory
log files of various applications are located in the /var directory.
Configuration files are stored in the /etc directory.
User folders are located in the /home directory.
check all add-on application packages in the /opt directory.
The /proc directory is a virtual filesystem that holds information on currently running processes. On shutdown, it destroys.
User binary files are located in the /bin directory.
The /lib directory stores shared library images and kernel modules.
Some Commands:
ls - lists the files and directories in a directory
cd - changes the current working directory
pwd - displays the current working directory
cp - copies a file or directory
mv - moves or renames a file or directory
rm - deletes a file or directory
mkdir - creates a new directory
rmdir - deletes an empty directory
echo - displays text to the screen
cat - displays the contents of a file
nano - a simple text editor
chmod - changes the permissions of a file or directory
chown - changes the owner of a file or directory
ping - tests connectivity to a network host
ssh - secure shell remote login protocol.