Function MIMETypeFromReader

internal/magic/magic.go:199–207

MIMETypeFromReader takes a reader, sniffs the beginning of it, and returns the mime (if sniffed, else "") and a new reader that's the concatenation of the bytes sniffed and the remaining reader.

(r io.Reader)

// that's the concatenation of the bytes sniffed and the remaining
// reader.
func MIMETypeFromReader(r io.Reader) (mime string, reader io.Reader) {
	var buf bytes.Buffer
	_, err := io.Copy(&buf, io.LimitReader(r, 1024))
	mime = MIMEType(buf.Bytes())
	if err != nil {
		return mime, io.MultiReader(&buf, errReader{err})
	}
	return mime, io.MultiReader(&buf, r)
}

// MIMETypeFromReaderAt takes a ReaderAt, sniffs the beginning of it,
// and returns the MIME type if sniffed, else the empty string.