This gist was created by the gisted code. Self-gisting! This is the first complete Go program I've ever written.

gist.go

package main

import (
	"bytes"
	"encoding/json"
	"flag"
	"fmt"
	"io/ioutil"
	"net/http"
	"os"
	"strings"
)

const (
	api_base = "https://api.github.com"
)

type GistFiles map[string]GistFile

type GistFile struct {
	Content string `json:"content"`
}

type CreateGist struct {
	Desc   string    `json:"description"`
	Public bool      `json:"public"`
	Files  GistFiles `json:"files"`
}

func jsonForFile(path string, contents string) []byte {
	file := GistFile{
		Content: contents,
	}

	files := CreateGist{
		Desc:   "",
		Public: true,
		Files: GistFiles{
			path: file,
		},
	}

	jsonVal, err := json.Marshal(files)
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}

	return jsonVal
}

func readGithubToken(path string) (string, error) {
	if strings.HasPrefix(path, "~") {
		home := os.Getenv("HOME")
		path = home + path[1:]
	}

	contents, err := ioutil.ReadFile(path)
	return strings.Split(string(contents), "\n")[0], err
}

func main() {
	filename := flag.String("file", "", "target file")
	flag.Parse()

	if *filename == "" {
		fmt.Println("-file must have a value")
		os.Exit(1)
	}

	token, err := readGithubToken("~/.github_token")

	contents, err := ioutil.ReadFile(*filename)
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}

	jsonVal := jsonForFile(*filename, string(contents))

	client := &http.Client{}

	req, err := http.NewRequest("POST", api_base+"/gists", bytes.NewBuffer(jsonVal))
	req.Header.Add("Accept", "application/vnd.github.v3+json")
	req.Header.Add("Authorization", "token "+token)
	req.Header.Add("Content-Type", "application/json")

	resp, err := client.Do(req)
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}

	if resp.StatusCode == 201 {
		location, _ := resp.Location()
		fmt.Println(location)
	} else {
		fmt.Println("Unexpected response code: " + resp.Status)
		fmt.Println(resp)
	}
}