1// Copyright 2009 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5// +build ignore
6
7package main
8
9import (
10	"bytes"
11	"expvar"
12	"flag"
13	"fmt"
14	"io"
15	"log"
16	"net/http"
17	"os"
18	"os/exec"
19	"strconv"
20	"sync"
21)
22
23// hello world, the web server
24var helloRequests = expvar.NewInt("hello-requests")
25
26func HelloServer(w http.ResponseWriter, req *http.Request) {
27	helloRequests.Add(1)
28	io.WriteString(w, "hello, world!\n")
29}
30
31// Simple counter server. POSTing to it will set the value.
32type Counter struct {
33	mu sync.Mutex // protects n
34	n  int
35}
36
37// This makes Counter satisfy the expvar.Var interface, so we can export
38// it directly.
39func (ctr *Counter) String() string {
40	ctr.mu.Lock()
41	defer ctr.mu.Unlock()
42	return fmt.Sprintf("%d", ctr.n)
43}
44
45func (ctr *Counter) ServeHTTP(w http.ResponseWriter, req *http.Request) {
46	ctr.mu.Lock()
47	defer ctr.mu.Unlock()
48	switch req.Method {
49	case "GET":
50		ctr.n++
51	case "POST":
52		buf := new(bytes.Buffer)
53		io.Copy(buf, req.Body)
54		body := buf.String()
55		if n, err := strconv.Atoi(body); err != nil {
56			fmt.Fprintf(w, "bad POST: %v\nbody: [%v]\n", err, body)
57		} else {
58			ctr.n = n
59			fmt.Fprint(w, "counter reset\n")
60		}
61	}
62	fmt.Fprintf(w, "counter = %d\n", ctr.n)
63}
64
65// simple flag server
66var booleanflag = flag.Bool("boolean", true, "another flag for testing")
67
68func FlagServer(w http.ResponseWriter, req *http.Request) {
69	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
70	fmt.Fprint(w, "Flags:\n")
71	flag.VisitAll(func(f *flag.Flag) {
72		if f.Value.String() != f.DefValue {
73			fmt.Fprintf(w, "%s = %s [default = %s]\n", f.Name, f.Value.String(), f.DefValue)
74		} else {
75			fmt.Fprintf(w, "%s = %s\n", f.Name, f.Value.String())
76		}
77	})
78}
79
80// simple argument server
81func ArgServer(w http.ResponseWriter, req *http.Request) {
82	for _, s := range os.Args {
83		fmt.Fprint(w, s, " ")
84	}
85}
86
87// a channel (just for the fun of it)
88type Chan chan int
89
90func ChanCreate() Chan {
91	c := make(Chan)
92	go func(c Chan) {
93		for x := 0; ; x++ {
94			c <- x
95		}
96	}(c)
97	return c
98}
99
100func (ch Chan) ServeHTTP(w http.ResponseWriter, req *http.Request) {
101	io.WriteString(w, fmt.Sprintf("channel send #%d\n", <-ch))
102}
103
104// exec a program, redirecting output
105func DateServer(rw http.ResponseWriter, req *http.Request) {
106	rw.Header().Set("Content-Type", "text/plain; charset=utf-8")
107
108	date, err := exec.Command("/bin/date").Output()
109	if err != nil {
110		http.Error(rw, err.Error(), http.StatusInternalServerError)
111		return
112	}
113	rw.Write(date)
114}
115
116func Logger(w http.ResponseWriter, req *http.Request) {
117	log.Print(req.URL)
118	http.Error(w, "oops", http.StatusNotFound)
119}
120
121var webroot = flag.String("root", os.Getenv("HOME"), "web root directory")
122
123func main() {
124	flag.Parse()
125
126	// The counter is published as a variable directly.
127	ctr := new(Counter)
128	expvar.Publish("counter", ctr)
129	http.Handle("/counter", ctr)
130	http.Handle("/", http.HandlerFunc(Logger))
131	http.Handle("/go/", http.StripPrefix("/go/", http.FileServer(http.Dir(*webroot))))
132	http.Handle("/chan", ChanCreate())
133	http.HandleFunc("/flags", FlagServer)
134	http.HandleFunc("/args", ArgServer)
135	http.HandleFunc("/go/hello", HelloServer)
136	http.HandleFunc("/date", DateServer)
137	log.Fatal(http.ListenAndServe(":12345", nil))
138}
139