Subversion Repositories openrisc

// 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"
        "io"
        "log"
        "net/http"
        "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)
        }
}