// Copyright 2009 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. // HTTP file system request handler package http import ( "fmt"; "io"; "os"; "path"; "strings"; "utf8"; ) // TODO this should be in a mime package somewhere var contentByExt = map[string]string{ ".css": "text/css", ".gif": "image/gif", ".html": "text/html; charset=utf-8", ".jpg": "image/jpeg", ".js": "application/x-javascript", ".pdf": "application/pdf", ".png": "image/png", } // Heuristic: b is text if it is valid UTF-8 and doesn't // contain any unprintable ASCII or Unicode characters. func isText(b []byte) bool { for len(b) > 0 && utf8.FullRune(b) { rune, size := utf8.DecodeRune(b); if size == 1 && rune == utf8.RuneError { // decoding error return false } if 0x80 <= rune && rune <= 0x9F { return false } if rune < ' ' { switch rune { case '\n', '\r', '\t': // okay default: // binary garbage return false } } b = b[size:]; } return true; } func dirList(c *Conn, f *os.File) { fmt.Fprintf(c, "
\n");
	for {
		dirs, err := f.Readdir(100);
		if err != nil || len(dirs) == 0 {
			break
		}
		for _, d := range dirs {
			name := d.Name;
			if d.IsDirectory() {
				name += "/"
			}
			// TODO htmlescape
			fmt.Fprintf(c, "%s\n", name, name);
		}
	}
	fmt.Fprintf(c, "
\n"); } func serveFileInternal(c *Conn, r *Request, name string, redirect bool) { const indexPage = "/index.html"; // redirect .../index.html to .../ if strings.HasSuffix(r.URL.Path, indexPage) { Redirect(c, r.URL.Path[0:len(r.URL.Path)-len(indexPage)+1], StatusMovedPermanently); return; } f, err := os.Open(name, os.O_RDONLY, 0); if err != nil { // TODO expose actual error? NotFound(c, r); return; } defer f.Close(); d, err1 := f.Stat(); if err1 != nil { // TODO expose actual error? NotFound(c, r); return; } if redirect { // redirect to canonical path: / at end of directory url // r.URL.Path always begins with / url := r.URL.Path; if d.IsDirectory() { if url[len(url)-1] != '/' { Redirect(c, url+"/", StatusMovedPermanently); return; } } else { if url[len(url)-1] == '/' { Redirect(c, url[0:len(url)-1], StatusMovedPermanently); return; } } } // use contents of index.html for directory, if present if d.IsDirectory() { index := name + indexPage; ff, err := os.Open(index, os.O_RDONLY, 0); if err == nil { defer ff.Close(); dd, err := ff.Stat(); if err == nil { name = index; d = dd; f = ff; } } } if d.IsDirectory() { dirList(c, f); return; } // serve file // use extension to find content type. ext := path.Ext(name); if ctype, ok := contentByExt[ext]; ok { c.SetHeader("Content-Type", ctype) } else { // read first chunk to decide between utf-8 text and binary var buf [1024]byte; n, _ := io.ReadFull(f, &buf); b := buf[0:n]; if isText(b) { c.SetHeader("Content-Type", "text-plain; charset=utf-8") } else { c.SetHeader("Content-Type", "application/octet-stream") // generic binary } c.Write(b); } io.Copy(c, f); } // ServeFile replies to the request with the contents of the named file or directory. func ServeFile(c *Conn, r *Request, name string) { serveFileInternal(c, r, name, false) } type fileHandler struct { root string; prefix string; } // FileServer returns a handler that serves HTTP requests // with the contents of the file system rooted at root. // It strips prefix from the incoming requests before // looking up the file name in the file system. func FileServer(root, prefix string) Handler { return &fileHandler{root, prefix} } func (f *fileHandler) ServeHTTP(c *Conn, r *Request) { path := r.URL.Path; if !strings.HasPrefix(path, f.prefix) { NotFound(c, r); return; } path = path[len(f.prefix):]; serveFileInternal(c, r, f.root+"/"+path, true); }