Installing Brew in Mac

Homebrew is a free and open-source package manager for macOS that simplifies the process of installing, updating, and managing software packages on your Mac. It allows you to easily install and manage a wide range of software packages, libraries, and tools that are not included in macOS by default.

Homebrew uses a command-line interface to install packages and dependencies, which means that you can easily manage and customize your software installations using simple commands in the Terminal.

Some of the benefits of using Homebrew on your Mac include:

• Easy installation of software packages and dependencies
• Automatic updates of installed packages
• Uninstallation of packages and dependencies
• Ability to customize software installations with different options and versions
• Access to a large and active community of developers who contribute to Homebrew's package repository

Following are commands to install the brew and add it to CLI.

xcode-select --install

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)" 

Following will be at the end of the installation, Copy and run that in the Mac CLI. 
  (echo; echo 'eval "$(/opt/homebrew/bin/brew shellenv)"') >> /Users/<Username>/.zprofile\n    eval "$(/opt/homebrew/bin/brew shellenv)"

xcode-select --install is a command that installs the command-line tools for Xcode on your Mac. Xcode is a development environment for macOS that provides tools for developing software for macOS, iOS, watchOS, and tvOS. The command-line tools for Xcode include a variety of tools and libraries that are necessary for building and compiling software on your Mac, even if you are not using Xcode itself.
Running xcode-select --install will open a dialog box that prompts you to install the command-line tools for Xcode. This may take a few minutes to complete, depending on your internet connection speed.

The command /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)" installs Homebrew on your Mac. Homebrew is a package manager that allows you to easily install and manage software packages and libraries on your Mac.
The installation script for Homebrew will download and install the necessary files and dependencies for Homebrew, and will configure your system to use Homebrew as your default package manager.

The last command (echo; echo 'eval "$(/opt/homebrew/bin/brew shellenv)"') >> /Users/<Username>/.zprofile\n eval "$(/opt/homebrew/bin/brew shellenv)" adds the necessary configuration to your .zprofile file to ensure that Homebrew is properly configured on your system. This command adds a line to your .zprofile file that tells your terminal to evaluate the output of the brew shellenv command, which sets up your environment variables to use Homebrew. This ensures that when you open a new terminal session, your system is properly configured to use Homebrew.

Sed Command in MAC

The sed command is used to manipulate and edit text in Unix-based operating systems like macOS.

Method to use Sed in Mac

sudo sed -i "/kube/d" /etc/hosts

give error sed: 1: "/etc/hosts": extra characters at the end of h command

In the first command you provided, sudo sed -i "/kube/d" /etc/hosts, the -i option tells sed to edit the file in place, and /kube/d is the command that tells sed to delete any lines containing the string "kube" in the /etc/hosts file. However, this command does not work on macOS as it requires the -i option to have a backup file extension specified. The error message "sed: 1: "/etc/hosts": extra characters at the end of h command" is indicating that the command is not properly formatted for macOS.

To fix this, you can use the following command: sudo sed -i '' '/kube/d' /etc/hosts. The empty quotes after -i specify that no backup file should be created, and the '' is necessary for macOS to recognize the command properly. The /kube/d command remains the same and tells sed to delete any lines containing the string "kube" in the /etc/hosts file.

Following Syntax Worked. 

sudo sed -i '' '/kube/d' /etc/hosts

Issue with Mission Control in Mac 10.15.13

If you are experiencing issues with Mission Control on Mac version 10.15.13 after an update, there is a fix that involves using the Terminal app. Simply type or copy the following command: "defaults write com.apple.dock mcx-expose-disabled -bool FALSE", then type "killall Dock" to stop the Dock, which will automatically restart. After this, the Exposé activation should take effect.

Fix

• Go to the Terminal app
• Type or copy: defaults write com.apple.dock mcx-expose-disabled -bool FALSE 
• Then type: killall Dock to stop the Dock that will then automatically be restarted. Only then the Exposé activation will take effect.

Exposè/Mission Control Not Working Mac 10.15.2

The issue of Exposè/Mission Control not working in Mac 10.15.2 can be fixed by applying a defaults write command. First, open Terminal app and type or copy the following command:

defaults write com.apple.dock mcx-expose-disabled -bool FALSE

After running this command, restart the OSX Dock by typing the following command in Terminal:

killall Dock

This will enable the Exposè/Mission Control feature and fix the issue.