Working in the terminal.
WHAT SHELL IS DEFAULT
The Z shell, on current versions.
WHAT CHANGED
It replaced bash as the default, and bash remains available at an older version.
WHAT THAT MEANS
Scripts assuming the newer bash features may not work with the system version.
WHAT TO DO ABOUT IT
Install a current version separately, and declare it explicitly in scripts.
WHAT STANDARD UNIX TOOLS ARE PRESENT
Most, though many are older or different versions from those on Linux.
WHY THAT MATTERS
Command options differ, and scripts written for Linux frequently fail subtly.
WHAT TO DO ABOUT IT
Install the standard versions separately, where scripts depend on them.
WHAT APPLE-SPECIFIC TOOLS EXIST
Reading and writing preference values Managing software updates Managing disks and volumes Managing launch services and background jobs Managing profiles and configuration
WHAT TO LEARN FIRST
Navigating, permissions, processes, networking checks, and reading logs.
WHAT TO BE CAREFUL WITH
Commands run with elevated privileges Commands copied without understanding
WHY
There is no undo.
