Скачать или смотреть ALX 0x03 Shell, init files, variables and expansions Quiz Solution

Shell:
The shell is a program that interprets commands and scripts, providing a user interface to the operating system. It allows users to interact with the system by typing commands and executing them.

Init files:
Init files are shell scripts that are executed by the shell when it starts up. They are used to set environment variables, configure the shell, and perform other initialization tasks. There are different types of init files depending on the shell being used, such as ~/.bashrc for Bash and ~/.zshrc for Zsh.

Variables:
Variables are used to store values that can be accessed and manipulated by the shell. There are two types of variables in the shell: environment variables and shell variables. Environment variables are inherited by child processes and can be accessed by any program running in the shell. Shell variables are only accessible within the shell session and its child processes.

Expansions:
Expansions are a way of manipulating values stored in variables or commands in the shell. There are several types of expansions in the shell, including parameter expansion, command substitution, arithmetic expansion, and pathname expansion. Parameter expansion allows you to manipulate variables, such as replacing a substring or expanding to the length of the variable. Command substitution allows you to run a command and use its output as part of another command. Arithmetic expansion allows you to perform mathematical operations on variables. Pathname expansion allows you to expand a pattern into a list of filenames.