Rewriting my youtube-dl wrapper in Go

package main

import (
	"bufio"
	"fmt"
	"log"
	"net/http"
	"os"
	"os/exec"
	"strconv"

	"github.com/gorilla/mux"
)

var (
	Log *log.Logger
	Output string
)

func _execute(url string) (error) {
	// reset last output
	Output = ""
	cmd := exec.Command("/usr/local/bin/youtube-dl",
		"-f", "best",
		"--newline",
		"--no-call-home", "--no-check-certificate",
		"-o", "/mnt/HD/HD_a2/Public/Shared Videos/%(uploader)s/%(title)s-%(id)s.%(ext)s",
		url)
	out, err := cmd.StdoutPipe()
	if err != nil {
		return err
	}

	cmd.Start()
	scanner := bufio.NewScanner(out)
	for scanner.Scan() {
		Output = fmt.Sprintf("%s\n%s", Output, scanner.Text())
	}
	cmd.Wait()

	return nil
}

func showOutput(w http.ResponseWriter, r *http.Request) {
	w.WriteHeader(http.StatusOK)
	w.Header().Set("Content-Type", "text/plain")
	fmt.Fprintf(w, "%s", Output)
}

func download(w http.ResponseWriter, r *http.Request) {
	url := r.PostFormValue("url")
	go _execute(url)
	w.Header().Set("Location", "/static/success.html")
	w.WriteHeader(http.StatusFound)
}

func redirect(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Location", "/static/")
	w.WriteHeader(http.StatusFound)
}

func main() {
	Log = log.New(os.Stdout, "youtube-ex2", log.Lshortfile)
	port := 8080
	if len(os.Args) == 2 {
		args := os.Args[1:]
		port, _ = strconv.Atoi(args[0])
	}

	r := mux.NewRouter()
	r.HandleFunc("/", redirect)
	r.HandleFunc("/download", download).Methods("POST")
	r.HandleFunc("/progress", showOutput)
	r.PathPrefix("/static/").Handler(http.StripPrefix("/static/", http.FileServer(http.Dir("static"))))

	sport := fmt.Sprintf(":%d", port)
	log.Printf("Listening on %s", sport)
	log.Fatal(http.ListenAndServe(sport, r))
}

go get
GOOS=linux GOARCH=arm GOARM=7 CGO_ENABLED=0 go build

#!/bin/bash
PATH=/sbin:/usr/sbin:/bin:/usr/bin:/usr/local/bin
DESC="youtube-dl webserver"
NAME=youtube
PIDFILE=/var/run/$NAME.pid
SCRIPTNAME=/etc/init.d/$NAME

# Exit if the package is not installed
[ -x /opt/app/app ] || exit 0

. /etc/system.conf

DAEMON_ARGS="8080"

#
# Function that starts the daemon/service
#
do_start_app()
{
    ps x | grep "/opt/app/app $DAEMON_ARGS" | grep -qv grep
    if [ $? == 0 ]; then
        echo "$NAME is already running "
        return 1
    fi

    echo "Starting $DESC " "$NAME"
    cd /opt/app
    /opt/app/app $DAEMON_ARGS &
    pid=$!
    status=$?
    if [ $status = 0 ]; then
        echo $pid > $PIDFILE
        echo "$NAME started"
    else
        echo "$NAME failed to start"
    fi
}

do_start()
{
    do_start_app
}

do_stop_app()
{
    [ ! -f $PIDFILE ] && echo "$NAME not running ..." && return 0
    PID=`cat $PIDFILE`
    if ps -e | grep -q $PID
    then
        echo "Stopping $DESC" "$NAME $PID"
        kill $PID
        rm $PIDFILE
    fi
}

#
# Function that stops the daemon/service
#
do_stop()
{
	do_stop_app
}

case "$1" in
  start)
    do_start
    ;;
  stop)
    do_stop
    ;;
  status)
    ps x | grep "/opt/app/app $DAEMON_ARGS" | grep -qv grep
        if [ $? == 0 ]; then
            echo "$NAME is running "
        else
            echo "$NAME is not running "
        fi
    exit 0
    ;;
  restart|force-reload)
    do_stop && sleep 1 && do_start
    ;;
  *)
    echo "Usage: $SCRIPTNAME {start|stop|status|restart|force-reload}" >&2
    exit 1
    ;;
esac

exit 0

/etc/init.d/youtube start