Q2.In Linux (Shell), there are two types of variable:(1) System variables - Created and maintained by Linux itself. It has an Interactive prompt and also a scripting environment. It is object-oriented and not text-based. Works for Windows/Linux/Mac.
![]() ![]() To put that in perspective, the version of Bash used on your Mac was new when the first iPhone was introduced.Apple is likely using the older version because the licensing for the Bash shell changed from GNU GPL 2 (General Public License) to GNU GPLv3, which includes restrictions that could cause problems for Apple.Apple muddled along with the older version for quite a few years, but really, it’s time to move on to something more current.The Zsh included with macOS Catalina is version 5.7.1 and is the most current version at the time of Catalina’s release. They haven’t said specifically why the change is occurring, but we can make some educated guesses.Apple has been using the Bash shell since OS X Jaguar but hasn’t updated Bash since version 3.2 was released in 2007. Shell Scripts: The ability to run a file containing multiple shell commands.Apple is changing from the Bash shell to the Zsh (Z Shell). Command Execution: What happens when commands are run. Redirect: Controls the input and output of commands. Shell Scripts Common And Windows Upgrade All AccountsIf you would like to temporarily try out the Zsh, do the following:Launch Terminal, located at /Applications/Utilities.The shell being used in the current Terminal session will change to the Zsh and the command prompt will change to a percent sign (%).You can return to the bash shell by either quitting Terminal, or at the prompt enter:You can discover more about the Terminal app in the Rocket Yard guide: Tech 101: Introduction to the Mac’s Terminal App, Part OneNo matter which shell Apple sets for you as the default, you can change it with one of two methods:Depending on whether you wish to set Zsh or Bash as the default.You can also change the default shell for each user from the Users & Groups preference pane.What About the Warning Message to Change to Zsh?If you have Bash set as the default and you launch Terminal or open a new Terminal session, you will see the following message:“The default interactive shell is now zsh. It’s likely most Bash commands and scripts you may be using will run just fine under the Zsh.Add the Shebang #!/bin/bash as the first line in your Bash scripts to ensure compatibility.Zsh has been included with the macOS for quite a while it just was never the default before. Both are based on the older Bourne shell. If you upgraded your Mac from an earlier version of the macOS, then those existing user accounts are still using the Bash shell.You are, however, free to upgrade all accounts to Zsh, or downgrade an account to Bash (or for that matter, to any shell you wish to use).Not very Bash and Zsh have a very high level of compatibility between them. Apple will set the Zsh as the default for any new user account that is created in macOS Catalina or later. Applications like manycam for macIf you would like to discover more about the Bash and Zsh, you can check out the online documentation about each.Do you use the Terminal app often? And if so, what shell do you prefer to use? Let us know in the comments below. To do so would really require a book, or two.
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