tcptest/client.go

package main

import (
	"bufio"
	"flag"
	"fmt"
	"io"
	"net"
	"net/http"
	"os"
	"strings"
)

var (
	host   = flag.String("h", "localhost", "Server host")
	port   = flag.String("p", "26666", "Server port")
	proto  = flag.String("proto", "tcp", "Protocol to use (tcp, udp, http)")
	method = flag.String("method", "get", "HTTP method to use (get, post) - only for http protocol")
)

func main() {
	flag.Parse()

	switch strings.ToLower(*proto) {
	case "tcp":
		runTCPClient()
	case "udp":
		runUDPClient()
	case "http":
		runHTTPClient()
	default:
		fmt.Printf("Unsupported protocol: %s. Use tcp, udp, or http.\n", *proto)
	}
}

func runTCPClient() {
	// Connect to the server
	conn, err := net.Dial("tcp", *host+":"+*port)
	if err != nil {
		fmt.Printf("Failed to connect to server: %v\n", err)
		return
	}
	defer conn.Close()

	fmt.Printf("Connected to TCP server %s:%s\n", *host, *port)
	fmt.Println("Type messages to send to the server (type 'exit' to quit):")

	// Create a scanner to read from standard input
	scanner := bufio.NewScanner(os.Stdin)

	// Create a goroutine to read messages from the server
	go func() {
		serverScanner := bufio.NewScanner(conn)
		for serverScanner.Scan() {
			fmt.Printf("Server: %s\n", serverScanner.Text())
		}
	}()

	// Read from standard input and send to server
	for {
		if !scanner.Scan() {
			break
		}

		message := scanner.Text()
		if strings.TrimSpace(message) == "exit" {
			fmt.Println("Exiting...")
			break
		}

		// Send message to server
		_, err := fmt.Fprintln(conn, message)
		if err != nil {
			fmt.Printf("Failed to send message: %v\n", err)
			break
		}
	}

	if err := scanner.Err(); err != nil {
		fmt.Printf("Error reading input: %v\n", err)
	}
}

func runUDPClient() {
	// Resolve UDP address
	addr, err := net.ResolveUDPAddr("udp", *host+":"+*port)
	if err != nil {
		fmt.Printf("Failed to resolve UDP address: %v\n", err)
		return
	}

	// Connect to the server
	conn, err := net.DialUDP("udp", nil, addr)
	if err != nil {
		fmt.Printf("Failed to connect to UDP server: %v\n", err)
		return
	}
	defer conn.Close()

	fmt.Printf("Connected to UDP server %s:%s\n", *host, *port)
	fmt.Println("Type messages to send to the server (type 'exit' to quit):")

	// Create a scanner to read from standard input
	scanner := bufio.NewScanner(os.Stdin)

	// Create a goroutine to read responses from the server
	go func() {
		buf := make([]byte, 1024)
		for {
			n, _, err := conn.ReadFromUDP(buf)
			if err != nil {
				fmt.Printf("Error reading from UDP server: %v\n", err)
				return
			}
			fmt.Printf("Server: %s\n", string(buf[:n]))
		}
	}()

	// Read from standard input and send to server
	for {
		if !scanner.Scan() {
			break
		}

		message := scanner.Text()
		if strings.TrimSpace(message) == "exit" {
			fmt.Println("Exiting...")
			break
		}

		// Send message to server
		_, err := conn.Write([]byte(message))
		if err != nil {
			fmt.Printf("Failed to send message: %v\n", err)
			break
		}
	}

	if err := scanner.Err(); err != nil {
		fmt.Printf("Error reading input: %v\n", err)
	}
}

func runHTTPClient() {
	// HTTP server runs on port+1
	portInt := parseInt(*port)
	httpPort := fmt.Sprintf("%d", portInt+1)
	url := fmt.Sprintf("http://%s:%s/ping", *host, httpPort)

	fmt.Printf("Connecting to HTTP server %s:%s\n", *host, httpPort)
	fmt.Println("Type messages to send to the server (type 'exit' to quit):")

	// Create a scanner to read from standard input
	scanner := bufio.NewScanner(os.Stdin)

	// Read from standard input and send to server
	for {
		if !scanner.Scan() {
			break
		}

		message := scanner.Text()
		if strings.TrimSpace(message) == "exit" {
			fmt.Println("Exiting...")
			break
		}

		// Send message to server
		var resp *http.Response
		var err error

		switch strings.ToLower(*method) {
		case "post":
			resp, err = http.Post(url, "text/plain", strings.NewReader(message))
		case "get":
			// For GET requests, we'll add the message as a query parameter
			getURL := url
			if message != "" {
				getURL += "?data=" + message
			}
			resp, err = http.Get(getURL)
		default:
			fmt.Printf("Unsupported HTTP method: %s. Use get or post.\n", *method)
			return
		}

		if err != nil {
			fmt.Printf("Failed to send message: %v\n", err)
			break
		}

		// Read response
		body, err := io.ReadAll(resp.Body)
		resp.Body.Close()
		if err != nil {
			fmt.Printf("Failed to read response: %v\n", err)
			break
		}

		fmt.Printf("Server: %s\n", string(body))
	}

	if err := scanner.Err(); err != nil {
		fmt.Printf("Error reading input: %v\n", err)
	}
}

// Helper function to convert string to int
func parseInt(s string) int {
	var result int
	fmt.Sscanf(s, "%d", &result)
	return result
}