This script can be used to download content from any link of any format

wget.go

// Package is used to download content from any link of any format
package main

import (
	"bytes"
	"flag"
	"fmt"
	"io"
	"io/ioutil"
	"net/http"
	"os"
	"path/filepath"
	"strings"
)

var verbose bool

func main() {
	w := flag.CommandLine.Output()
	path, link := ".", ""
	// verbose flag
	for _, arg := range []string{"v", "trace"} {
		flag.BoolVar(&verbose, arg, false, "Trace all the logs and calls")
	}
	// user email flags
	for _, arg := range []string{"url", "link", "u", "l"} {
		flag.StringVar(&link, arg, link, "Url/Link of content to download (required)")
	}
	// download at (path)
	for _, arg := range []string{"path", "p"} {
		flag.StringVar(&path, arg, path, "Download at path")
	}
	flag.Usage = func() {
		write(w, "Usage of", os.Args[0])
		write(w, "It is used to download content from any link of any format")
		write(w, "  -h, -help\n    \tThis help box")
		write(w, "  -v, -trace\n    \tTrace all the logs and calls")
		write(w, "  -u, -url string\n  -l, -link string\n     \tUrl/Link of content to download (required)")
		write(w, "  -p, -path string\n    \tSave Downloaded file at this path (default current directory)")
		write(w, "")
	}
	flag.Parse()

	if flag.NArg() > 0 {
		flag.Usage()
		return
	}

	if link == "" {
		write(w, "Download Link is required")
		write(w, "")
		flag.Usage()
		return
	}

	final(link, path)
}

func final(link, path string) {
	var err error
	w := flag.CommandLine.Output()
	log(w, "Link:", link)
	log(w, "Provided Path:", path)
	log(w, "Verbose:", verbose)

	name := filepath.Base(link)
	if path != "." {
		dir, input := path, filepath.Base(path)
		if strings.ContainsRune(input, '.') {
			name = input
			dir = filepath.Dir(path)
		} else {
			path = filepath.Join(path, name)
		}
		if dir != "." {
			err = os.MkdirAll(dir, 0755)
			if err != nil {
				report(w, "Invalid directory path provided:", dir, err)
				return
			}
		}
	} else {
		path = filepath.Join(path, name)
	}
	log(w, "Calculated Path:", path)

	out, err := os.Create(path)
	if err != nil {
		report(w, "Invalid path provided:", path, err)
		return
	}
	defer out.Close()

	// Download
	log(w, "Downloading download...")
	res, err := Get(link)
	if err != nil {
		report(w, "Unable to download:", link, err)
		return
	}
	all, err := ioutil.ReadAll(res.Body)
	if err != nil {
		report(w, "unable to read response:", err, "response:", res)
		return
	}

	log(w, "Copying data...")
	_, err = io.Copy(out, bytes.NewReader(all))
	if err != nil {
		report(w, "unable to copy response:", err, "response:", res)
		return
	}
	write(w, "File downloaded at", path)
}

func Get(u string, cookies ...*http.Cookie) (*http.Response, error) {
	req, _ := http.NewRequest(http.MethodGet, u, nil)
	for _, cook := range cookies {
		req.AddCookie(cook)
	}
	return http.DefaultClient.Do(req)
}

func log(w io.Writer, msg string, args ...interface{}) {
	if verbose {
		write(w, msg, args...)
	}
}

func report(w io.Writer, msg string, args ...interface{}) {
	write(w, msg, args...)
	os.Exit(1)
}

func write(w io.Writer, msg string, args ...interface{}) {
	_, _ = fmt.Fprintln(w, append([]interface{}{msg}, args...)...)
}