Create main.go

main

src/main.go

@@ -0,0 +1,117 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"net"
+	"os"
+	"os/signal"
+	"strings"
+	"syscall"
+	"time"
+)
+
+var stopPing chan bool
+
+func main() {
+	ipv4Flag := flag.Bool("4", false, "Ping IPv4 address")
+	ipv6Flag := flag.Bool("6", false, "Ping IPv6 address")
+	countFlag := flag.Int("n", 0, "Number of pings (default: infinite)")
+	timeoutFlag := flag.Int("t", 1, "Time interval between pings in seconds")
+	flag.Parse()
+
+	if *ipv4Flag && *ipv6Flag {
+		fmt.Println("Both -4 and -6 flags cannot be used together.")
+		os.Exit(1)
+	}
+
+	args := flag.Args()
+	if len(args) < 2 {
+		fmt.Println("Usage: tcping [-4] [-6] [-n count] [-t timeout] address port")
+		os.Exit(1)
+	}
+
+	address := args[0]
+	port := args[1]
+
+	if *ipv4Flag || (!*ipv6Flag && isIPv4(address)) {
+		address = resolveAddress(address, "ipv4")
+	} else if *ipv6Flag || isIPv6(address) {
+		address = resolveAddress(address, "ipv6")
+	} else {
+		// Default to IPv4 if no -4 or -6 flags specified and address is not explicitly IPv6
+		address = resolveAddress(address, "ipv4")
+	}
+
+	fmt.Printf("Pinging %s:%s...\n", address, port)
+	stopPing = make(chan bool, 1)
+	interrupt := make(chan os.Signal, 1)
+	signal.Notify(interrupt, os.Interrupt, syscall.SIGTERM)
+
+	go ping(address, port, *countFlag, *timeoutFlag)
+
+	select {
+	case <-interrupt:
+		fmt.Println("\nPing interrupted.")
+		stopPing <- true
+	case <-stopPing:
+		fmt.Println("\nPing stopped.")
+	}
+}
+
+func resolveAddress(address, version string) string {
+	ipList, err := net.LookupIP(address)
+	if err != nil {
+		fmt.Printf("Failed to resolve %s: %v\n", address, err)
+		os.Exit(1)
+	}
+
+	for _, ip := range ipList {
+		if version == "ipv4" && ip.To4() != nil {
+			return ip.String()
+		} else if version == "ipv6" && ip.To16() != nil && ip.To4() == nil {
+			return "[" + ip.String() + "]"
+		}
+	}
+
+	fmt.Printf("No %s addresses found for %s\n", version, address)
+	os.Exit(1)
+	return ""
+}
+
+func isIPv4(address string) bool {
+	return strings.Count(address, ":") == 0
+}
+
+func isIPv6(address string) bool {
+	return strings.Count(address, ":") >= 2
+}
+
+func ping(address, port string, count, timeout int) {
+	defer func() {
+		stopPing <- true
+	}()
+
+	for i := 0; count == 0 || i < count; i++ {
+		select {
+		case <-stopPing:
+			return
+		default:
+			start := time.Now()
+			conn, err := net.DialTimeout("tcp", address+":"+port, time.Duration(timeout)*time.Second)
+			if err != nil {
+				fmt.Printf("Failed to connect to %s:%s: %v\n", address, port, err)
+			} else {
+				conn.Close()
+				elapsed := time.Since(start).Milliseconds()
+				fmt.Printf("tcping %s:%s in %dms\n", address, port, elapsed)
+			}
+
+			if count != 0 && i == count-1 {
+				break
+			}
+
+			time.Sleep(time.Duration(timeout) * time.Second)
+		}
+	}
+}