send_hello

package main
import "net"
import "fmt"
import "time"

type Pair struct {
    a int
    b error
}

func send_data(n int, target string, content string, result chan Pair) {
    conn, err := net.DialTimeout("tcp", target, time.Duration(1 * time.Second))
    if err != nil {
        result <- Pair{n, err}
        return
    }
    defer conn.Close()

    _, err = conn.Write([]byte(content))
    if err != nil {
        result <- Pair{n, err}
        return
    }

    reply := make([]byte, 1024)
    conn.SetDeadline(time.Now().Add(1e9))
    _, err = conn.Read(reply)
    if err != nil {
        result <- Pair{n, err}
        return
    }
    result <- Pair{n, nil}
    return
}

func main() {
    targets := [...]string{"127.0.0.1:7777", "127.0.0.1:8888"}
    result := make(chan Pair)
    for i, target := range targets {
        go send_data(i, target, "hello\n", result)
    }

    for i := 0; i < len(targets); i++ {
        r := <-result
        if r.b != nil {
            fmt.Printf("%d %s\n", r.a, r.b.Error())
        } else {
            fmt.Printf("%d OK\n", r.a)
        }
    }
}