do a few

cmd/budgetchat.go

@@ -0,0 +1,19 @@
+package cmd
+
+import (
+	"git.red-panda.pet/pandaware/protohacking/x/budgetchat"
+	"github.com/spf13/cobra"
+)
+
+var budgetChat = &cobra.Command{
+	Use:     "budgetchat",
+	Aliases: []string{"p3"},
+	Short:   "Problem 3: Budget Chat",
+	Run: func(cmd *cobra.Command, args []string) {
+		runServer(budgetchat.New)
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(budgetChat)
+}

cmd/meanstoanend.go

@@ -0,0 +1,19 @@
+package cmd
+
+import (
+	"git.red-panda.pet/pandaware/protohacking/x/meanstoanend"
+	"github.com/spf13/cobra"
+)
+
+var meansToAnEnd = &cobra.Command{
+	Use:     "meanstoanend",
+	Aliases: []string{"p2"},
+	Short:   "Problem 2: Means to an End",
+	Run: func(cmd *cobra.Command, args []string) {
+		runServer(meanstoanend.New)
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(meansToAnEnd)
+}

cmd/root.go

@@ -0,0 +1,37 @@
+package cmd
+
+import (
+	"log"
+	"net"
+
+	"github.com/spf13/cobra"
+)
+
+var (
+	ip    net.IP
+	port  uint16
+	proto string
+	v6    bool
+)
+
+var rootCmd = &cobra.Command{
+	Use:   "protohacking",
+	Short: "Protohackers challenge servers",
+	Run: func(cmd *cobra.Command, args []string) {
+		cmd.Help()
+	},
+}
+
+func init() {
+	pflags := rootCmd.PersistentFlags()
+	pflags.Uint16VarP(&port, "port", "p", 8088, "Port to TCP listen on")
+	pflags.IPVarP(&ip, "ip", "i", net.IPv6unspecified, "Address to listen on")
+	pflags.BoolVarP(&v6, "v6", "6", true, "Whether to use IPv6")
+	pflags.StringVar(&proto, "proto", "tcp", "Either tcp or udp")
+}
+
+func Execute() {
+	if err := rootCmd.Execute(); err != nil {
+		log.Fatal("fatal error", "err", err)
+	}
+}

cmd/smoke-test.go

@@ -0,0 +1,19 @@
+package cmd
+
+import (
+	"git.red-panda.pet/pandaware/protohacking/x/smoketest"
+	"github.com/spf13/cobra"
+)
+
+var smokeTest = &cobra.Command{
+	Use:     "smoketest",
+	Aliases: []string{"p0"},
+	Short:   "Problem 0: Smoke Test",
+	Run: func(cmd *cobra.Command, args []string) {
+		runServer(smoketest.New)
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(smokeTest)
+}

cmd/util.go

@@ -0,0 +1,37 @@
+package cmd
+
+import (
+	"net"
+	"net/netip"
+
+	"github.com/charmbracelet/log"
+)
+
+func runServer(server func(net.Listener) error) {
+	if proto != "tcp" && proto != "udp" {
+		log.Fatal("unsupported protocol, must be either tcp or udp")
+	}
+
+	if v6 {
+		proto += "6"
+	}
+
+	addr, ok := netip.AddrFromSlice(ip)
+	if !ok {
+		log.Fatal("invalid ip")
+	}
+
+	ap := netip.AddrPortFrom(addr, port)
+
+	listener, err := net.Listen(proto, ap.String())
+	if err != nil {
+		log.Fatal("unable to listen", "err", err)
+	}
+
+	log.Info("starting server", "proto", proto, "ip", ip, "port", port)
+
+	err = server(listener)
+	if err != nil {
+		log.Fatal("error while handling connections", "err", err)
+	}
+}