├── sendfile_other.go
├── sendfile_unix.go
└── main.go


/sendfile_other.go:
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 1 | // +build !darwin,!dragonfly,!freebsd,!linux,!netbsd,!openbsd,!solaris
 2 | 
 3 | package main
 4 | 
 5 | import (
 6 | 	"io"
 7 | 	"net"
 8 | 	"os"
 9 | )
10 | 
11 | func sendfile(c *net.TCPConn, f *os.File, fi os.FileInfo) {
12 | 	io.Copy(c, f)
13 | }
14 | 


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/sendfile_unix.go:
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 1 | // +build darwin dragonfly freebsd linux netbsd openbsd solaris
 2 | 
 3 | package main
 4 | 
 5 | import (
 6 | 	"fmt"
 7 | 	"net"
 8 | 	"os"
 9 | 	"syscall"
10 | )
11 | 
12 | func sendfile(c *net.TCPConn, f *os.File, fi os.FileInfo) {
13 | 	sockFile, err := c.File()
14 | 	if err != nil {
15 | 		fmt.Fprint(c, Error(fmt.Sprintf("couldn't get file sock: %x", err)))
16 | 	}
17 | 	syscall.Sendfile(int(sockFile.Fd()), int(f.Fd()), nil, int(fi.Size()))
18 | }
19 | 


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/main.go:
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  1 | package main
  2 | 
  3 | import (
  4 | 	"bufio"
  5 | 	"bytes"
  6 | 	"flag"
  7 | 	"fmt"
  8 | 	"log"
  9 | 	"net"
 10 | 	"os"
 11 | 	"path/filepath"
 12 | 	"strings"
 13 | )
 14 | 
 15 | var (
 16 | 	host    = flag.String("host", "localhost", "hostname used in links")
 17 | 	address = flag.String("address", "localhost", "listen on address")
 18 | 	port    = flag.String("port", "70", "listen on port")
 19 | 	root    string
 20 | )
 21 | 
 22 | type Entry struct {
 23 | 	Type     byte
 24 | 	Display  string
 25 | 	Selector string
 26 | 	Hostname string
 27 | 	Port     string
 28 | }
 29 | 
 30 | func (e Entry) String() string {
 31 | 	return fmt.Sprintf("%c%s\t%s\t%s\t%s\r\n",
 32 | 		e.Type, e.Display, e.Selector, e.Hostname, e.Port)
 33 | }
 34 | 
 35 | type Listing []Entry
 36 | 
 37 | func (l Listing) String() string {
 38 | 	var b bytes.Buffer
 39 | 	for _, e := range l {
 40 | 		if e.Type == 0 {
 41 | 			continue // skip sentinel value
 42 | 		}
 43 | 		fmt.Fprint(&b, e)
 44 | 	}
 45 | 	fmt.Fprint(&b, ".\r\n")
 46 | 	return b.String()
 47 | }
 48 | 
 49 | func (l Listing) VisitDir(path string, f os.FileInfo) error {
 50 | 	if len(l) == 0 {
 51 | 		l = append(l, Entry{}) // sentinel value
 52 | 		return nil
 53 | 	}
 54 | 	l = append(l, Entry{'1', f.Name(), path[len(root)-1:], *host, *port})
 55 | 	return filepath.SkipDir
 56 | }
 57 | 
 58 | var suffixes = map[string]byte{
 59 | 	"aiff": 's',
 60 | 	"au":   's',
 61 | 	"gif":  'g',
 62 | 	"go":   '0',
 63 | 	"html": 'h',
 64 | 	"jpeg": 'I',
 65 | 	"jpg":  'I',
 66 | 	"mp3":  's',
 67 | 	"png":  'I',
 68 | 	"txt":  '0',
 69 | 	"wav":  's',
 70 | }
 71 | 
 72 | func (l Listing) VisitFile(path string, f os.FileInfo) {
 73 | 	t := byte('9') // Binary
 74 | 	for s, c := range suffixes {
 75 | 		if strings.HasSuffix(path, "."+s) {
 76 | 			t = c
 77 | 			break
 78 | 		}
 79 | 	}
 80 | 	l = append(l, Entry{t, f.Name(), path[len(root)-1:], *host, *port})
 81 | }
 82 | 
 83 | func Serve(c *net.TCPConn) {
 84 | 	defer c.Close()
 85 | 	connbuf := bufio.NewReader(c)
 86 | 	p, _, err := connbuf.ReadLine()
 87 | 	if err != nil {
 88 | 		fmt.Fprint(c, Error("invalid request"))
 89 | 		return
 90 | 	}
 91 | 	filename := root + filepath.Clean("/"+string(p))
 92 | 	fi, err := os.Stat(filename)
 93 | 	if err != nil {
 94 | 		fmt.Fprint(c, Error("not found"))
 95 | 		return
 96 | 	}
 97 | 	if fi.IsDir() {
 98 | 		var list Listing
 99 | 		walkFn := func(path string, info os.FileInfo, err error) error {
100 | 			if info.IsDir() {
101 | 				return list.VisitDir(path, info)
102 | 			}
103 | 
104 | 			list.VisitFile(path, info)
105 | 			return nil
106 | 		}
107 | 
108 | 		filepath.Walk(filename, walkFn)
109 | 		fmt.Fprint(c, list)
110 | 		return
111 | 	}
112 | 	f, err := os.Open(filename)
113 | 	if err != nil {
114 | 		fmt.Fprint(c, Error("couldn't open file"))
115 | 		return
116 | 	}
117 | 	sendfile(c, f, fi)
118 | }
119 | 
120 | func Error(msg string) Listing {
121 | 	return Listing{Entry{Type: 3, Display: msg}}
122 | }
123 | 
124 | func main() {
125 | 	flag.Usage = func() {
126 | 		fmt.Fprintf(os.Stderr, "usage: %s directory\n", os.Args[0])
127 | 		flag.PrintDefaults()
128 | 		os.Exit(2)
129 | 	}
130 | 
131 | 	flag.Parse()
132 | 	if root = flag.Arg(0); root == "" {
133 | 		flag.Usage()
134 | 	}
135 | 	if strings.HasSuffix(root, "/") {
136 | 		root = root[:len(root)-1]
137 | 	}
138 | 	listenAddr := net.JoinHostPort(*address, *port)
139 | 	l, err := net.Listen("tcp", listenAddr)
140 | 	if err != nil {
141 | 		log.Fatal(err)
142 | 	}
143 | 
144 | 	for {
145 | 		c, err := l.Accept()
146 | 		tcpConn := c.(*net.TCPConn)
147 | 		if err != nil {
148 | 			log.Fatal(err)
149 | 		}
150 | 		go Serve(tcpConn)
151 | 	}
152 | }
153 | 


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