You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: main.go
    path of file: ./repos/syncthing/cmd/syncthing
    
    the code of the file until where you have to start completion: // Copyright (C) 2014 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at https://mozilla.org/MPL/2.0/.

package main

import (
	"bytes"
	"context"
	"crypto/tls"
	"errors"
	"fmt"
	"io"
	"log"
	"net/http"
	_ "net/http/pprof" // Need to import this to support STPROFILER.
	"net/url"
	"os"
	"os/signal"
	"path"
	"path/filepath"
	"regexp"
	"runtime/pprof"
	"sort"
	"strconv"
	"strings"
	"syscall"
	"time"

	"github.com/alecthomas/kong"
	_ "github.com/syncthing/syncthing/li
    
func auditWriter(auditFile string) io.Writer {
	var fd io.Writer
	var err error
	var auditDest string
	var auditFlags int

	if auditFile == "-" {
		fd = os.Stdout
		auditDest = "stdout"
	} else if auditFile == "--" {
		fd = os.Stderr
		auditDest = "stderr"
	} else {
		if auditFile == "" {
			auditFile = locations.GetTimestamped(locations.AuditLog)
			auditFlags = os.O_WRONLY | os.O_CREATE | os.O_EXCL
		} else {
			auditFlags = os.O_WRONLY | os.O_CREATE | os.O_APPEND
		}
		fd, err = os.OpenFile(auditFile, auditFlags, 0o600)
		if err != nil {
			l.Warnln("Audit:", err)
			os.Exit(svcutil.ExitError.AsInt())
		}
		auditDest = auditFile
	}

	l.Infoln("Audit log in", auditDest)

	return fd
}