only follow redirect once

main.go

@@ -33,23 +33,28 @@ var (
  verboseMode bool = false
 )
 
-func getRemoteFileSize(url string) (int64, error) {
+func getRemoteFileSize(url string) (string, int64, error) {
+ // TODO: this needs a retry
  resp, err := http.DefaultClient.Head(url)
  if err != nil {
- return int64(-1), err
+ return "", int64(-1), err
  }
  defer resp.Body.Close()
+ trueUrl := resp.Request.URL.String()
+ if (trueUrl != url) {
+ fmt.Printf("Redirected to %s\n", trueUrl)
+ }
 
  fileSize := resp.ContentLength
  if fileSize <= 0 {
- return int64(-1), fmt.Errorf("unable to determine file size")
+ return "", int64(-1), fmt.Errorf("unable to determine file size")
  }
  _fileSize = fileSize
- return fileSize, nil
+ return trueUrl, fileSize, nil
 }
 
 func downloadFileToBuffer(url string, concurrency int, retries int) (*bytes.Buffer, error) {
- fileSize, err := getRemoteFileSize(url)
+ trueUrl, fileSize, err := getRemoteFileSize(url)
  if err != nil {
  return nil, err
  }
@@ -104,7 +109,7 @@ func downloadFileToBuffer(url string, concurrency int, retries int) (*bytes.Buff
  CheckRedirect: checkRedirectFunc,
  }
 
- req, err := http.NewRequest("GET", url, nil)
+ req, err := http.NewRequest("GET", trueUrl, nil)
  if err != nil {
  // This needs to be a time.Duration to make everything happy
  fmt.Printf("Error creating request: %v\n", err)
@@ -212,6 +217,7 @@ func main() {
  retries := flag.Int("r", 5, "Number of retries when attempting to retreive file")
  extract := flag.Bool("x", false, "extract tar file")
  verbose := flag.Bool("v", false, "verbose mode")
+ force := flag.Bool("f", false, "force download, overwriting existing file")
  flag.Parse()
 
  // check required positional arguments
@@ -225,7 +231,7 @@ func main() {
  dest := args[1]
 
  // ensure dest does not exist
- if _, err := os.Stat(dest); !os.IsNotExist(err) {
+ if _, err := os.Stat(dest); !*force || !os.IsNotExist(err) {
  fmt.Printf("Destination %s already exists\n", dest)
  os.Exit(1)
  }