downloads youtube links in new goroutines, has a strange bug where it tries to add a "" url

dl.go

package main

import (
	"fmt"
	"io/ioutil"
	"os"
	"os/exec"
	"strings"
	"sync"
)

// Global so my functions can use it without passing it to them
var wg sync.WaitGroup

func main() {
	// Make sure they used it correctly
	if len(os.Args) != 2 {
		fmt.Println("Usage: " + os.Args[0] + " <textfile>")
		os.Exit(1)
	}

	// Goes ahead and reads the bytes into the bytes variable
	bytes, err := ioutil.ReadFile(os.Args[1])
	handle(err)
	// Convert it into a string then a list
	text := string(bytes)
	urls := strings.Split(text, "\n")

	// For every url download in a new goroutine
	for index, item := range urls {
		wg.Add(1)
		go dl(item, index)
	}
	// Wait for all the goroutines to finish
	wg.Wait()
}

func dl(url string, id int) {
	fmt.Printf("[Goroutine %d] Starting to download %s\n", id, url)
	cmd := exec.Command("youtube-dl", url)
	// I wish i knew how to remap file descriptors to go into variables *sigh*
	// If i could i would parse the shit out of the output and error

	_, err := cmd.Output()
	if err != nil {
		fmt.Printf("[Goroutine %d] Failed to download %s\n", id, url)
	} else {
		fmt.Printf("[Goroutine %d] Downloaded %s\n", id, url)
	}

	wg.Done()
}

func handle(err error) {
	if err != nil {
		fmt.Println(err.Error())
		os.Exit(1)
	}
}