fetchall/main.go

@@ -2,6 +2,61 @@
 
 package main
 
-func main() {
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"time"
+)
 
+type HttpGetResult struct {
+	Success bool
+	Body    string
+	Elapsed time.Duration
+	Size    int
+	Url     string
+	Error   error
+}
+
+func (result HttpGetResult) String() string {
+	if result.Success {
+		return fmt.Sprintf("%v\t%v\t%v", result.Elapsed, result.Size, result.Url)
+	} else {
+		return result.Error.Error()
+	}
+}
+
+func GetHttpBody(url string, ch chan HttpGetResult) {
+	startTime := time.Now()
+	resp, err := http.Get(url)
+	if err != nil {
+		ch <- HttpGetResult{Success: false, Error: err}
+		return
+	}
+	defer resp.Body.Close()
+	data, err := io.ReadAll(resp.Body)
+	if err != nil {
+		ch <- HttpGetResult{Success: false, Error: err}
+		return
+	}
+	ch <- HttpGetResult{
+		Success: true,
+		Body:    string(data),
+		Elapsed: time.Since(startTime),
+		Size:    len(data),
+		Url:     url,
+	}
+}
+
+func main() {
+	startTime := time.Now()
+	urls, ch := os.Args[1:], make(chan HttpGetResult)
+	for _, url := range urls {
+		go GetHttpBody(url, ch)
+	}
+	for i := 0; i < len(urls); i++ {
+		fmt.Println(<-ch)
+	}
+	fmt.Println(time.Since(startTime), "elapsed")
 }

sum/sum.go

@@ -3,5 +3,5 @@
 package sum
 
 func Sum(a, b int64) int64 {
-	return 0
+	return a + b
 }

urlfetch/main.go

@@ -2,6 +2,26 @@
 
 package main
 
-func main() {
+import (
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"os"
+)
 
+func main() {
+	urls := os.Args[1:]
+	for _, url := range urls {
+		resp, err := http.Get(url)
+		if err != nil {
+			log.Fatal("fetch:", err)
+		}
+		defer resp.Body.Close()
+		body, err := io.ReadAll(resp.Body)
+		if err != nil {
+			log.Fatal("fetch:", err)
+		}
+		fmt.Println(string(body))
+	}
 }

wordcount/main.go

@@ -2,6 +2,33 @@
 
 package main
 
-func main() {
+import (
+	"bufio"
+	"fmt"
+	"os"
+)
 
+func LinesCountInFile(lines map[string]int, filename string) {
+	file, err := os.Open(filename)
+	if err != nil {
+		return
+	}
+	defer file.Close()
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		line := scanner.Text()
+		lines[line]++
+	}
+}
+
+func main() {
+	filenames, lines := os.Args[1:], make(map[string]int)
+	for _, filename := range filenames {
+		LinesCountInFile(lines, filename)
+	}
+	for line, count := range lines {
+		if count != 1 {
+			fmt.Printf("%v\t%v\n", count, line)
+		}
+	}
 }