76 lines
1.3 KiB
Go
76 lines
1.3 KiB
Go
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package main
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import (
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"flag"
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"fmt"
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"net"
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"os"
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"time"
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)
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const (
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defaultServer = "google.com"
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defaultPort = "80"
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)
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var verbose bool
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func connect(addr string, dport string, six bool, timeout time.Duration) error {
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_, _, err := net.SplitHostPort(addr)
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if err != nil {
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addr = net.JoinHostPort(addr, dport)
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}
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proto := "tcp"
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if six {
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proto += "6"
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}
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if verbose {
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fmt.Printf("connecting to %s/%s... ", addr, proto)
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os.Stdout.Sync()
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}
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conn, err := net.DialTimeout(proto, addr, timeout)
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if err != nil {
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if verbose {
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fmt.Println("failed.")
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}
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return err
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}
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if verbose {
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fmt.Println("OK")
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}
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conn.Close()
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return nil
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}
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func main() {
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var (
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port string
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timeout time.Duration
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six bool
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)
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flag.BoolVar(&six, "6", false, "require IPv6")
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flag.StringVar(&port, "p", defaultPort, "`port` to connect to instead of "+defaultPort)
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flag.DurationVar(&timeout, "t", 3*time.Second, "`timeout`")
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flag.BoolVar(&verbose, "v", false, "verbose mode: print server and protocol when connecting")
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flag.Parse()
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var servers []string
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if flag.NArg() == 0 {
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servers = []string{defaultServer}
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} else {
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servers = flag.Args()
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}
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for _, server := range servers {
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err := connect(server, port, six, timeout)
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if err != nil {
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os.Exit(1)
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}
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}
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}
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