55 lines
1.1 KiB
Go
55 lines
1.1 KiB
Go
// 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 148.
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// Fetch saves the contents of a URL into a local file.
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package main
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import (
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"fmt"
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"io"
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"net/http"
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"os"
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"path"
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)
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//!+
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// Fetch downloads the URL and returns the
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// name and length of the local file.
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func fetch(url string) (filename string, n int64, err error) {
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resp, err := http.Get(url)
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if err != nil {
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return "", 0, err
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}
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defer resp.Body.Close()
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local := path.Base(resp.Request.URL.Path)
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if local == "/" {
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local = "index.html"
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}
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f, err := os.Create(local)
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if err != nil {
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return "", 0, err
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}
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n, err = io.Copy(f, resp.Body)
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// Close file, but prefer error from Copy, if any.
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if closeErr := f.Close(); err == nil {
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err = closeErr
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}
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return local, n, err
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}
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//!-
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func main() {
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for _, url := range os.Args[1:] {
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local, n, err := fetch(url)
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if err != nil {
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fmt.Fprintf(os.Stderr, "fetch %s: %v\n", url, err)
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continue
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}
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fmt.Fprintf(os.Stderr, "%s => %s (%d bytes).\n", url, local, n)
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}
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}
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