Go Twitter Command line client

ts.go

// ts -- twitter search
package main

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

type JTweets struct {
	Results []Result
}

type Result struct {
	From_user      string
	From_user_name string
	Text           string
}

var (
	nresults = flag.Int("n", 20, "Maximum results (up to 100)")
	since    = flag.String("d", "", "Search since this date (YYYY-MM-DD)")
)

const (
	queryURI = "http://search.twitter.com/search.json?q=%s&rpp=%d"
)

// ts queries twitter via the search API
func ts(s string, date string, n int) {
	var q string
	if len(date) > 0 {
		q = fmt.Sprintf(queryURI+"&since=%s", url.QueryEscape(s), n, date)
	} else {
		q = fmt.Sprintf(queryURI, url.QueryEscape(s), n)
	}

	r, err := http.Get(q)
	if err != nil {
		fmt.Fprintf(os.Stderr, "%v\n", err)
		return
	}
	defer r.Body.Close()

	if r.StatusCode == http.StatusOK {
		readjson(r.Body)
	} else {
		fmt.Fprintf(os.Stderr,
			"Twitter is unable to search for %s (%s)\n", s, r.Status)
	}
}

// readjson reads and decodes the JSON response from twitter
func readjson(r io.Reader) {
	var twitter JTweets
	b, err := ioutil.ReadAll(r)
	if err != nil {
		fmt.Fprintf(os.Stderr, "%v\n", err)
		return
	}
	jerr := json.Unmarshal(b, &twitter)
	if jerr != nil {
		fmt.Fprintf(os.Stderr, "Unable to parse the JSON feed (%v)\n", jerr)
		return
	}
	for _, t := range twitter.Results {
		fmt.Printf("%-25s @%-15s %s\n", t.From_user_name, t.From_user, t.Text)
	}
}

func main() {
	flag.Parse()
	for _, s := range flag.Args() {
		ts(s, *since, *nresults)
	}
}