main.go

package main

import (
	"flag"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"path"

	"github.com/fcjr/aia-transport-go"
)

func main() {
	out := flag.String("o", "", "Write output to <file> instead of stdout")
	useRemoteName := flag.Bool("O", false, "Write output to a local file named like the remote file")

	flag.Parse()

	args := flag.Args()
	if len(args) < 1 {
		fmt.Println("Usage: aiaurl [-o filename | -O] <url>")
		os.Exit(1)
	}
	url := args[0]

	tr, err := aia.NewTransport()
	if err != nil {
		log.Fatalf("Failed to initialize AIA transport: %v", err)
	}
	client := &http.Client{Transport: tr}

	resp, err := client.Get(url)
	if err != nil {
		log.Fatalf("Download failed: %v", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		log.Fatalf("Server returned status: %s", resp.Status)
	}

	var dest io.Writer
	if *out != "" {
		f, err := os.Create(*out)
		if err != nil {
			log.Fatal(err)
		}
		defer f.Close()
		dest = f
	} else if *useRemoteName {
		filename := path.Base(url)
		if filename == "." || filename == "/" {
			log.Fatal("Could not determine remote name from URL")
		}
		f, err := os.Create(filename)
		if err != nil {
			log.Fatal(err)
		}
		defer f.Close()
		dest = f
	} else {
		dest = os.Stdout
	}

	_, err = io.Copy(dest, resp.Body)
	if err != nil {
		log.Fatalf("Error saving file: %v", err)
	}
}