nak/helpers.go

package main

import (
	"bytes"
	"fmt"
	"io"
	"net/url"
	"os"

	"github.com/urfave/cli/v2"
)

func getStdin() string {
	stat, _ := os.Stdin.Stat()
	if (stat.Mode() & os.ModeCharDevice) == 0 {
		read := bytes.NewBuffer(make([]byte, 0, 1000))
		_, err := io.Copy(read, os.Stdin)
		if err == nil {
			return read.String()
		}
	}
	return ""
}

func getStdinOrFirstArgument(c *cli.Context) string {
	target := c.Args().First()
	if target != "" {
		return target
	}
	return getStdin()
}

func validateRelayURLs(wsurls []string) error {
	for _, wsurl := range wsurls {
		u, err := url.Parse(wsurl)
		if err != nil {
			return fmt.Errorf("invalid relay url '%s': %s", wsurl, err)
		}

		if u.Scheme != "ws" && u.Scheme != "wss" {
			return fmt.Errorf("relay url must use wss:// or ws:// schemes, got '%s'", wsurl)
		}

		if u.Host == "" {
			return fmt.Errorf("relay url '%s' is missing the hostname", wsurl)
		}
	}

	return nil
}