flag package - flag - pkg.go.dev
https://pkg.go.dev/flag15.03.2022 · Flag parsing stops just before the first non-flag argument ("-" is a non-flag argument) or after the terminator "--". Integer flags accept 1234, 0664, 0x1234 and may be negative. Boolean flags may be: 1, 0, t, f, T, F, true, false, TRUE, FALSE, True, False. Duration flags accept any input valid for time.ParseDuration.