first

.idea/.gitignore

@@ -0,0 +1,8 @@
+# 默认忽略的文件
+/shelf/
+/workspace.xml
+# 基于编辑器的 HTTP 客户端请求
+/httpRequests/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml

.idea/Study.iml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="WEB_MODULE" version="4">
+  <component name="Go" enabled="true" />
+  <component name="NewModuleRootManager">
+    <content url="file://$MODULE_DIR$" />
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

.idea/modules.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/.idea/Study.iml" filepath="$PROJECT_DIR$/.idea/Study.iml" />
+    </modules>
+  </component>
+</project>

.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+  </component>
+</project>

day3/fetchall.go

@@ -0,0 +1,52 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"strings"
+	"time"
+)
+
+func main() {
+	CheckHttpArgs(os.Args[1:])
+	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.Sprintln(err)
+		return
+	}
+	nbyte, err := io.Copy(io.Discard, resp.Body)
+	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, nbyte, url)
+}
+
+func CheckHttpArgs(args []string) {
+	for i, _ := range args {
+		// 去除空格
+		strings.TrimSpace(args[i])
+		// 去除 /
+		strings.Trim(args[i], "/")
+
+		if strings.HasPrefix(args[i], "http") != true {
+			args[i] = "http://" + args[i]
+		}
+	}
+}

day3/hello.go

@@ -0,0 +1,7 @@
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println("hello world!")
+}

day3/server1.go

@@ -0,0 +1,17 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+)
+
+func main() {
+	http.HandleFunc("/", handler)
+	log.Fatal(http.ListenAndServe("localhost:8090", nil))
+}
+
+func handler(w http.ResponseWriter, r *http.Request) {
+	fmt.Fprintf(w, "url.Path = %q \n", r.URL.Path)
+
+}

day3/server2.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:8090", 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", count)
+	mu.Unlock()
+}

day4/boiling.go

@@ -0,0 +1,18 @@
+package main
+
+import "fmt"
+
+const boilinF = 212.0 // 常量
+
+func main() {
+	f := boilinF
+	c := (f - 32) * 5 / 9
+	fmt.Printf("Boiling point = %g°F or %g°C\n",
+		f, c)
+	fmt.Printf("%gF = %gC", 32.0, fToC(32.0))
+}
+
+// fToC
+func fToC(f float64) float64 {
+	return (f - 32) * 5 / 9
+}

day4/echo4.go

@@ -0,0 +1,20 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"strings"
+)
+
+var n = flag.Bool("n", false,
+	"omit trailing newline")
+var sep = flag.String("s", "",
+	"separtor")
+
+func main() {
+	flag.Parse()
+	fmt.Print(strings.Join(flag.Args(), *sep))
+	if !*n {
+		fmt.Println()
+	}
+}

go.mod

@@ -0,0 +1,3 @@
+module Study
+
+go 1.19