[RUBY] Command mechanism and management tools

Command mechanism and management tools

Purpose

• Understand the tools used in environment construction and how they work
• Understand why you manage with a package management tool

shell

Simply put, it is like a "window that connects the terminal and the OS." Reads the command entered from the terminal, passes the instruction to the OS, returns the result to the terminal, and performs operations such as display and execution.

zsh

zsh is one of the shells. Running echo $ SHELL in the terminal reveals that the shell you are currently using is zsh

PATH

Variables for the OS called "environment variables". Information on multiple absolute paths is stored in the PATH. When a command is entered, the shell searches for files in directories in the path described in PATH. In other words, if you save the absolute path in the PATH and show where the application is, you can type the application command no matter where you execute the command.

Command line tools

A group of applications operated by commands. By installing a command line tool, you can install applications other than those that the OS can operate with commands from the beginning on your PC.

Command Line Tools

A command line tool dedicated to macOS. Originally, macOS comes standard with applications and functions that can be operated with Linux commands. Many applications that operate other than Linux commands can be installed on a PC at once by installing Command Line Tools.

For example, Command Line Tools also includes what is called a "compiler" that is required to install a number of software. Also, I was able to operate Git with the git command because I installed Command Line Tools (it may be available by default). Therefore, in the environment construction curriculum that I went to first, I started by introducing command line tools, then installing Homebrew, and enabling Homebrew to be operated by the brew command.

that's all