Apple unveiled macOS Catalina yesterday with support for iPad apps and lots of new features, but a big change for developers and power users was missing from the on stage presentation. Starting with macOS Catalina, Macs will now use zsh as the default login shell and interactive shell across the operating system. All newly created user accounts in macOS Catalina will use zsh by default. Bash will still be available, but Apple is signaling that developers should start moving to zsh on macOS Mojave or earlier in anticipation of bash eventually going away in macOS.
Apple hasn’t explained exactly why it’s making this change, but bash isn’t exactly a modern shell as it’s implemented in macOS, and a switch to something less aging makes a lot more sense for the company.
MacDailyNews Take: Big news for developers. For more on info on using Zsh instead of Bash, Ali Spittel covered it for Dev here.