initial commit

nexd.go

@@ -0,0 +1,143 @@
+package main
+
+import (
+	"bufio"
+	"io"
+	"io/fs"
+	"log"
+	"net"
+	"os"
+	"path"
+	"sort"
+	"strings"
+)
+
+func write(w io.Writer, s string) (int, error) {
+	return w.Write([]byte(s + "\n"))
+}
+
+type Handler struct {
+	FS fs.FS
+}
+
+func (h *Handler) handleDir(p string, w io.Writer) error {
+	if header, err := fs.ReadFile(h.FS, path.Join(p, ".header")); err == nil {
+		write(w, string(header))
+	}
+	modified := true
+	if _, err := fs.Stat(h.FS, path.Join(p, ".modified")); err != nil {
+		modified = false
+	}
+	asc := false
+	if _, err := fs.Stat(h.FS, path.Join(p, ".desc")); err != nil {
+		asc = true
+	}
+	dirents, err := fs.ReadDir(h.FS, p)
+	if err != nil {
+		return err
+	}
+	sort.Slice(dirents, func(i, j int) bool {
+		if modified {
+			st1, err := dirents[i].Info()
+			if err != nil {
+				return false
+			}
+			st2, err := dirents[j].Info()
+			if err != nil {
+				return false
+			}
+			return st1.ModTime().After(st2.ModTime())
+		} else if asc {
+			return dirents[i].Name() < dirents[j].Name()
+		} else {
+			return dirents[i].Name() > dirents[j].Name()
+		}
+	})
+	for _, entry := range dirents {
+		name := entry.Name()
+		if strings.HasPrefix(name, ".") {
+			continue
+		}
+		i, err := entry.Info()
+		if err != nil {
+			continue
+		}
+		if i.Mode()&(1<<2) == 0 {
+			continue
+		}
+		if entry.IsDir() {
+			name += "/"
+		}
+		if _, err := write(w, "=> "+name); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (h *Handler) Handle(p string, w io.Writer) error {
+	if p == "/" || p == "" {
+		p = "."
+	} else {
+		p = strings.Trim(p, "/")
+	}
+
+	f, err := h.FS.Open(p)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	stat, err := f.Stat()
+	if err != nil {
+		return err
+	}
+
+	if stat.IsDir() {
+		index, err := h.FS.Open(path.Join(p, "index"))
+		if err != nil {
+			return h.handleDir(p, w)
+		}
+		defer index.Close()
+		f = index
+	}
+
+	_, err = io.Copy(w, f)
+	return err
+}
+
+func serve(h *Handler, rw io.ReadWriteCloser) {
+	defer rw.Close()
+	scanner := bufio.NewScanner(rw)
+	scanner.Scan()
+	sel := scanner.Text()
+	if err := h.Handle(sel, rw); err != nil {
+		rw.Write([]byte("document not found"))
+		log.Println(err)
+	}
+}
+
+func listenAndServe(h *Handler) error {
+	l, err := net.Listen("tcp", ":1900")
+	if err != nil {
+		return err
+	}
+	defer l.Close()
+
+	for {
+		rw, err := l.Accept()
+		if err != nil {
+			return err
+		}
+		go serve(h, rw)
+	}
+}
+
+func main() {
+	if len(os.Args) < 2 {
+		log.Fatal("usage: nexd path")
+	}
+
+	h := Handler{FS: os.DirFS(os.Args[1])}
+	log.Fatal(listenAndServe(&h))
+}