Add CLI as example usage

cmd/plugctl/main.go

@@ -0,0 +1,35 @@
+// The plugctl command provides manual CLI control over a Kasa KP105 smart plug.
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+
+	"gitea.drjosh.dev/josh/plugctl"
+)
+
+var kasaPlugAddr = flag.String("kasa-addr", "KP105:9999", "Address of Kasa smart plug")
+
+func main() {
+	flag.Parse()
+
+	plug := plugctl.Plug{Addr: *kasaPlugAddr}
+
+	switch flag.Arg(0) {
+	case "on":
+		if err := plug.TurnOn(); err != nil {
+			log.Printf("Couldn't turn on smart plug: %v", err)
+		}
+	case "off":
+		if err := plug.TurnOff(); err != nil {
+			log.Printf("Couldn't turn off smart plug: %v", err)
+		}
+	case "state":
+		state, err := plug.RelayState()
+		if err != nil {
+			log.Printf("Couldn't get current relay state: %v", err)
+		}
+		fmt.Println(state)
+	}
+}