gurl - get URL

gurl.go

// gurl - get the contents of a url to stdout, -v show response on stderr
package main

import (
	"errors"
	"flag"
	"fmt"
	"io"
	"net/http"
	"os"
	"time"
)

var verbose bool
var username, password string

func init() {
	flag.BoolVar(&verbose, "v", false, "verbose")
	flag.StringVar(&username, "username", "", "username")
	flag.StringVar(&password, "password", "", "password")
	flag.Parse()
}

func dumpresp(resp *http.Response) {
	for k, v := range resp.Header {
		fmt.Fprintf(os.Stderr, "%s: %v\n", k, v)
	}
}

func requestOut(uri string, w io.Writer, r *http.Response, t time.Time) {
	io.Copy(w, r.Body)
	if verbose {
		fmt.Fprintf(os.Stderr, "\n%s %s %v\nRequest Time: %.3f\n",
			uri, r.Proto, r.Status, float64(time.Since(t))/1e9)
		dumpresp(r)
	}
}

func authrequest(c *http.Client, uri, user, pass string) (*http.Response, error) {
	if len(user) == 0 {
		return nil, errors.New("specify username")
	}
	authreq, authnerr := http.NewRequest("GET", uri, nil)
	if authnerr != nil {
		return nil, authnerr
	}
	authreq.SetBasicAuth(user, pass)
	authresp, autherr := c.Do(authreq)
	if autherr != nil {
		return nil, autherr
	}
	return authresp, autherr
}

func main() {
	var t0 time.Time
	var client = &http.Client{}
	for _, uri := range flag.Args() {
		t0 = time.Now()
		r, err := client.Get(uri)
		if err != nil {
			fmt.Fprintf(os.Stderr, "%v\n", err)
			continue
		}
		switch r.StatusCode {
		case http.StatusOK:
			requestOut(uri, os.Stdout, r, t0)

		case http.StatusUnauthorized, http.StatusProxyAuthRequired:
			authresp, autherr := authrequest(client, uri, username, password)
			if autherr != nil {
				fmt.Fprintf(os.Stderr, "bad authenticated request: %v\n", autherr)
			} else {
				requestOut(uri, os.Stdout, authresp, t0)
			}

		default:
			fmt.Fprintf(os.Stderr, "GET %s, status: %d)\n", uri, r.StatusCode)
		}
		r.Body.Close()
	}
}