subtree(users/wpcarro): docking briefcase at '24f5a642'

git-subtree-dir: users/wpcarro
git-subtree-mainline: 464bbcb15c
git-subtree-split: 24f5a642af
Change-Id: I6105b3762b79126b3488359c95978cadb3efa789

users/wpcarro/tools/rfcToKindle/main.go

@@ -0,0 +1,89 @@
+// Author: wpcarro@gmail.com
+//
+// Wirelessly transfer RFC documents to your Kindle to device for an alternative
+// medium for reading.
+//
+// Usage:
+// ```shell
+// > go run rfcToKindle.go -document rfc6479 -recipient username@kindle.com
+// ```
+//
+// This uses `sendgmr` to send the file to the Kindle. Make sure:
+// 1. That `sendgmr` is installed and available on $PATH.
+// 2. That it is configured to work with your preferred email address.
+// 3. That the email address `sendgmr` is configured to use is whitelisted in
+//    your Kindle "Personal Document Settings".
+
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os"
+	"os/exec"
+	"strings"
+)
+
+func main() {
+	document := flag.String("document", "", "(Required) The name of the document to fetch. For example \"RFC6479\".")
+	recipient := flag.String("recipient", "", "(Required) The email address of the Kindle device.")
+	subject := flag.String("subject", "", "(Optional) The email address of the Kindle device.")
+	flag.Parse()
+
+	if *document == "" {
+		// TODO: Is log.Fatal the best function to use here?
+		log.Fatal("-document cannot be empty. See -help for more information.")
+	}
+
+	if *recipient == "" {
+		log.Fatal("-recipient cannot be empty. See -help for more information.")
+	}
+
+	*document = strings.ToLower(*document)
+
+	url := fmt.Sprintf("https://www.ietf.org/rfc/%s.txt", *document)
+	resp, err := http.Get(url)
+	fmt.Printf("Downloading %s ... ", url)
+
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer resp.Body.Close()
+
+	f, err := ioutil.TempFile("", fmt.Sprintf("%s-*.txt", *document))
+	if err != nil {
+		log.Fatal(err)
+	}
+	// TODO: Verify if this is cleaning up or not.
+	defer os.Remove(f.Name())
+
+	_, err = io.Copy(f, resp.Body)
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Println("done.")
+
+	if *subject == "" {
+		*subject = fmt.Sprintf("%s - Sent from rfcToKindle.go", *document)
+	}
+
+	// Although I couldn't find it documented anywhere, the email sent to the
+	// Kindle must have a body, even if the body isn't used for anything.
+	fmt.Printf("Emailing %s to %s ... ", f.Name(), *recipient)
+	cmd := exec.Command("sendgmr",
+		fmt.Sprintf("--to=%s", *recipient),
+		fmt.Sprintf("--body_file=%s", f.Name()),
+		fmt.Sprintf("--subject=%s", *subject),
+		fmt.Sprintf("--attachment_files=%s", f.Name()))
+	err = cmd.Run()
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Println("done.")
+
+	os.Exit(0)
+}