Solution: Collect data from urls

---

examples/collect-data-from-urls/collect_data_from_urls.go

package main

import (
    "bufio"
    "fmt"
    "io/ioutil"
    "log"
    "net/http"
    "os"
)

func main() {
    if len(os.Args) != 2 {
        fmt.Printf("Usage: %s FILENAME\n", os.Args[0])
        os.Exit(1)
    }

    urls := readFile(os.Args[1])

    for _, url := range urls[0:3] {
        text, err := get(url)
        if err != nil {
            fmt.Println(err)
            return
        }
        fmt.Printf("%-40s %6v\n", url, len(text))
    }
}

func readFile(filename string) []string {
    urls := make([]string, 0, 50)

    log.Println(filename)
    fh, err := os.Open(filename)
    if err != nil {
        fmt.Println(err)
        os.Exit(1)
    }
    scanner := bufio.NewScanner(fh)
    for scanner.Scan() {
        line := scanner.Text()
        urls = append(urls, line)
    }
    if err := scanner.Err(); err != nil {
        fmt.Fprintln(os.Stderr, "reading:", err)
        os.Exit(1)
    }
    return urls
}

func get(url string) (string, error) {
    text := ""
    resp, err := http.Get(url)
    if err != nil {
        return text, err
    }

    defer resp.Body.Close()
    body, err := ioutil.ReadAll(resp.Body)
    if err != nil {
        return text, err
    }

    return string(body), nil
}