blob: a8fd99aa4be3c02669dc1fa7035a056ea9511a1d [file] [log] [blame]
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package main
import (
"bytes"
"expvar"
"flag"
"fmt"
"http"
"io"
"log"
"os"
"strconv"
)
// hello world, the web server
var helloRequests = expvar.NewInt("hello-requests")
func HelloServer(w http.ResponseWriter, req *http.Request) {
helloRequests.Add(1)
io.WriteString(w, "hello, world!\n")
}
// Simple counter server. POSTing to it will set the value.
type Counter struct {
n int
}
// This makes Counter satisfy the expvar.Var interface, so we can export
// it directly.
func (ctr *Counter) String() string { return fmt.Sprintf("%d", ctr.n) }
func (ctr *Counter) ServeHTTP(w http.ResponseWriter, req *http.Request) {
switch req.Method {
case "GET":
ctr.n++
case "POST":
buf := new(bytes.Buffer)
io.Copy(buf, req.Body)
body := buf.String()
if n, err := strconv.Atoi(body); err != nil {
fmt.Fprintf(w, "bad POST: %v\nbody: [%v]\n", err, body)
} else {
ctr.n = n
fmt.Fprint(w, "counter reset\n")
}
}
fmt.Fprintf(w, "counter = %d\n", ctr.n)
}
// simple flag server
var booleanflag = flag.Bool("boolean", true, "another flag for testing")
func FlagServer(w http.ResponseWriter, req *http.Request) {
w.Header().Set("Content-Type", "text/plain; charset=utf-8")
fmt.Fprint(w, "Flags:\n")
flag.VisitAll(func(f *flag.Flag) {
if f.Value.String() != f.DefValue {
fmt.Fprintf(w, "%s = %s [default = %s]\n", f.Name, f.Value.String(), f.DefValue)
} else {
fmt.Fprintf(w, "%s = %s\n", f.Name, f.Value.String())
}
})
}
// simple argument server
func ArgServer(w http.ResponseWriter, req *http.Request) {
for _, s := range os.Args {
fmt.Fprint(w, s, " ")
}
}
// a channel (just for the fun of it)
type Chan chan int
func ChanCreate() Chan {
c := make(Chan)
go func(c Chan) {
for x := 0; ; x++ {
c <- x
}
}(c)
return c
}
func (ch Chan) ServeHTTP(w http.ResponseWriter, req *http.Request) {
io.WriteString(w, fmt.Sprintf("channel send #%d\n", <-ch))
}
// exec a program, redirecting output
func DateServer(rw http.ResponseWriter, req *http.Request) {
rw.Header().Set("Content-Type", "text/plain; charset=utf-8")
r, w, err := os.Pipe()
if err != nil {
fmt.Fprintf(rw, "pipe: %s\n", err)
return
}
p, err := os.StartProcess("/bin/date", []string{"date"}, &os.ProcAttr{Files: []*os.File{nil, w, w}})
defer r.Close()
w.Close()
if err != nil {
fmt.Fprintf(rw, "fork/exec: %s\n", err)
return
}
defer p.Release()
io.Copy(rw, r)
wait, err := p.Wait(0)
if err != nil {
fmt.Fprintf(rw, "wait: %s\n", err)
return
}
if !wait.Exited() || wait.ExitStatus() != 0 {
fmt.Fprintf(rw, "date: %v\n", wait)
return
}
}
func Logger(w http.ResponseWriter, req *http.Request) {
log.Print(req.URL.Raw)
w.WriteHeader(404)
w.Write([]byte("oops"))
}
var webroot = flag.String("root", "/home/rsc", "web root directory")
func main() {
flag.Parse()
// The counter is published as a variable directly.
ctr := new(Counter)
http.Handle("/counter", ctr)
expvar.Publish("counter", ctr)
http.Handle("/", http.HandlerFunc(Logger))
http.Handle("/go/", http.StripPrefix("/go/", http.FileServer(http.Dir(*webroot))))
http.Handle("/flags", http.HandlerFunc(FlagServer))
http.Handle("/args", http.HandlerFunc(ArgServer))
http.Handle("/go/hello", http.HandlerFunc(HelloServer))
http.Handle("/chan", ChanCreate())
http.Handle("/date", http.HandlerFunc(DateServer))
err := http.ListenAndServe(":12345", nil)
if err != nil {
log.Panicln("ListenAndServe:", err)
}
}