53 lines
1.0 KiB
Go
53 lines
1.0 KiB
Go
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// Copyright © 2016 Alan A. A. Donovan & Brian W. Kernighan.
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// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
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// See page 21.
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//!+
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// Server3 is a minimal "echo" and counter server.
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package main
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import (
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"fmt"
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"log"
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"net/http"
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"sync"
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)
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var mu sync.Mutex
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var count int
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func main() {
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http.HandleFunc("/", handler)
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http.HandleFunc("/count", counter)
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log.Fatal(http.ListenAndServe("localhost:8000", nil))
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}
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//!+handler
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// handler echoes the HTTP request.
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func handler(w http.ResponseWriter, r *http.Request) {
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fmt.Fprintf(w, "%s %s %s\n", r.Method, r.URL, r.Proto)
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for k, v := range r.Header {
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fmt.Fprintf(w, "Header[%q] = %q\n", k, v)
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}
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fmt.Fprintf(w, "Host = %q\n", r.Host)
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fmt.Fprintf(w, "RemoteAddr = %q\n", r.RemoteAddr)
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if err := r.ParseForm(); err != nil {
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log.Print(err)
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}
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for k, v := range r.Form {
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fmt.Fprintf(w, "Form[%q] = %q\n", k, v)
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}
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}
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//!-handler
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// counter echoes the number of calls so far.
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func counter(w http.ResponseWriter, r *http.Request) {
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mu.Lock()
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fmt.Fprintf(w, "Count %d", count)
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mu.Unlock()
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}
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//!-
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