second commit

.gitignore

@@ -0,0 +1 @@
+.DS_Store

fetchall/fetchall.go

@@ -0,0 +1,38 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"time"
+)
+func main(){
+	start := time.Now()
+	ch := make(chan string)
+	for _,url := range os.Args[1:]{
+		go fetch(url,ch)
+
+	}
+	for range os.Args[1:]{
+		fmt.Println(<-ch)
+	}
+	fmt.Printf("%.2fs  elapsed\n",time.Since(start).Seconds())
+}
+func fetch(url string,ch chan<- string) {
+	start := time.Now()
+	resp,err := http.Get(url)
+	if err != nil {
+		ch <- fmt.Sprint(err)
+		return
+	}
+	nbytes,err := io.Copy(ioutil.Discard,resp.Body)
+	resp.Body.Close()
+	if err != nil{
+		ch <- fmt.Sprintf("while reading %s: %v",url,err)
+		return
+	}
+	secs := time.Since(start).Seconds()
+	ch <- fmt.Sprintf("%.2fs  %7d  %s",secs,nbytes,url)
+}

hello/hello.go

@@ -0,0 +1,6 @@
+package main
+
+import "fmt"
+func main(){
+	fmt.Println("Hello, 界!")
+}

os.Args/os.Args.go

@@ -0,0 +1,11 @@
+package main
+
+import (
+	"fmt"
+	"os"
+)
+func main(){
+	for num,url :=range os.Args{
+		fmt.Printf("%d: %s\n",num,url)
+	}
+}

server0/server0.go

@@ -0,0 +1,15 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+)
+
+func main() {
+	http.HandleFunc("/", handler)
+	log.Fatal(http.ListenAndServe("localhost:8000", nil))
+}
+func handler(w http.ResponseWriter, r *http.Request) {
+	fmt.Fprintf(w, "URL.Path= %q\n", r.URL.Path)
+}

server1/server1.go

@@ -0,0 +1,29 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+	"sync"
+)
+
+var mu sync.Mutex
+var count int
+
+func main() {
+	http.HandleFunc("/", handler)
+	http.HandleFunc("/count", counter)
+	log.Fatal(http.ListenAndServe("localhost:8000", nil))
+
+}
+func handler(w http.ResponseWriter, r *http.Request) {
+	mu.Lock()
+	count++
+	mu.Unlock()
+	fmt.Fprintf(w, "URL.Path= %q\n", r.URL.Path)
+}
+func counter(w http.ResponseWriter, r *http.Request) {
+	mu.Lock()
+	fmt.Fprintf(w, "Count %d\n", count)
+	mu.Unlock()
+}

server2/server2.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+)
+
+func main() {
+	http.HandleFunc("/", handler)
+	log.Fatal(http.ListenAndServe("localhost:8000", nil))
+}
+func handler(w http.ResponseWriter, r *http.Request) {
+	fmt.Fprintf(w, "%s %s %s\n", r.Method, r.URL, r.Proto)
+	for k, v := range r.Header {
+		fmt.Fprintf(w, "Header[%q] = %q\n", k, v)
+	}
+	fmt.Fprintf(w, "Host = %q\n", r.Host)
+	fmt.Fprintf(w, "RemoteAddr = %q\n", r.RemoteAddr)
+	if err := r.ParseForm(); err != nil {
+		log.Print(err)
+	}
+	r.ParseForm()/*
+	http://localhost:8000/?q=query，
+	此时，得到的map中的key,value就是q,query。
+	*/
+	fmt.Println(r.Form)
+	for k, v := range r.Form {
+		fmt.Fprintf(w, "Form[%q] = %q\n", k, v)
+	}
+
+}