sw_vers
sw_versPrint macOS version information.
Runs as
sw_vers|macOSPrint macOS version information.
sw_vers|macOSPrint the macOS product name, version or build. With none selected all three are printed.
product_versionboolean-productNameboolean-productVersionboolean-buildVersionfigcompletionBefore it fills your prompt, Otty checks the installed sw_vers against its version. A form that does not match your version is not offered.