Support directory listing

Resolves #5.

CONFIGURATION.md

@@ -68,6 +68,8 @@ When accessing a directory the file `index.gemini` or `index.gmi` is served.
 
 Serve static files from specified root directory.
 
+Directory listing may be enabled by adding `listdirectory: true`.
+
 #### Proxy
 
 Forward request to Gemini server at specified URL.
@@ -96,6 +98,7 @@ hosts:
     -
       path: /sites
       root: /home/gemini.rocks/data/sites
+      listdirectory: true
     -
       path: ^/(help|info)$
       root: /home/gemini.rocks/data/help

config.go

@@ -22,6 +22,9 @@ type pathConfig struct {
 	Proxy   string
 	Command string
 
+	// List directory entries
+	ListDirectory bool
+
 	r   *regexp.Regexp
 	cmd []string
 }

server.go

@@ -12,6 +12,8 @@ import (
 	"os"
 	"os/exec"
 	"path"
+	"path/filepath"
+	"sort"
 	"strconv"
 	"strings"
 	"time"
@@ -48,7 +50,66 @@ func writeStatus(c net.Conn, code int) {
 	writeHeader(c, code, meta)
 }
 
-func serveFile(c net.Conn, requestData, filePath string) {
+func serveDirectory(c net.Conn, request *url.URL, dirPath string) {
+	var files []os.FileInfo
+	err := filepath.Walk(dirPath, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		} else if path == dirPath {
+			return nil
+		}
+		files = append(files, info)
+		if info.IsDir() {
+			return filepath.SkipDir
+		}
+		return nil
+	})
+	if err != nil {
+		writeStatus(c, gemini.StatusTemporaryFailure)
+		return
+	}
+	// List directories first
+	sort.Slice(files, func(i, j int) bool {
+		iDir := files[i].IsDir() || files[i].Mode()&os.ModeSymlink != 0
+		jDir := files[j].IsDir() || files[j].Mode()&os.ModeSymlink != 0
+		if iDir != jDir {
+			return iDir
+		}
+		return i < j
+	})
+
+	writeHeader(c, gemini.StatusSuccess, "text/gemini; charset=utf-8")
+
+	c.Write([]byte("# " + request.Path + "\r\n\r\n"))
+
+	if request.Path != "/" {
+		c.Write([]byte("=> ../ ../\r\n\r\n"))
+	}
+
+	for _, info := range files {
+		fileName := info.Name()
+		filePath := url.PathEscape(info.Name())
+		if info.IsDir() || info.Mode()&os.ModeSymlink != 0 {
+			fileName += "/"
+			filePath += "/"
+		}
+
+		c.Write([]byte("=> " + fileName + " " + filePath + "\r\n"))
+
+		if info.IsDir() || info.Mode()&os.ModeSymlink != 0 {
+			c.Write([]byte("\r\n"))
+			continue
+		}
+
+		modified := "Never"
+		if !info.ModTime().IsZero() {
+			modified = info.ModTime().Format("2006-01-02 3:04 PM")
+		}
+		c.Write([]byte(modified + " - " + formatFileSize(info.Size()) + "\r\n\r\n"))
+	}
+}
+
+func serveFile(c net.Conn, request *url.URL, requestData, filePath string, listDir bool) {
 	fi, err := os.Stat(filePath)
 	if os.IsNotExist(err) {
 		writeStatus(c, gemini.StatusNotFound)
@@ -58,6 +119,9 @@ func serveFile(c net.Conn, requestData, filePath string) {
 		return
 	}
 
+	originalPath := filePath
+
+	var fetchIndex bool
 	if mode := fi.Mode(); mode.IsDir() {
 		if requestData[len(requestData)-1] != '/' {
 			// Add trailing slash
@@ -66,6 +130,8 @@ func serveFile(c net.Conn, requestData, filePath string) {
 			return
 		}
 
+		fetchIndex = true
+
 		_, err := os.Stat(path.Join(filePath, "index.gemini"))
 		if err == nil {
 			filePath = path.Join(filePath, "index.gemini")
@@ -76,6 +142,10 @@ func serveFile(c net.Conn, requestData, filePath string) {
 
 	fi, err = os.Stat(filePath)
 	if os.IsNotExist(err) {
+		if fetchIndex && listDir {
+			serveDirectory(c, request, originalPath)
+			return
+		}
 		writeStatus(c, gemini.StatusNotFound)
 		return
 	} else if err != nil {
@@ -268,29 +338,29 @@ func handleConn(c net.Conn) {
 		matchedHost = true
 
 		for _, serve := range config.Hosts[hostname] {
-			if serve.Proxy != "" {
-				if serve.r != nil && serve.r.Match(pathBytes) {
+			if serve.r != nil && serve.r.Match(pathBytes) {
+				if serve.Proxy != "" {
 					serveProxy(c, requestData, serve.Proxy)
 					return
-				} else if serve.r == nil && strings.HasPrefix(request.Path, serve.Path) {
-					serveProxy(c, requestData, serve.Proxy)
+				} else if serve.cmd != nil {
+					serveCommand(c, serve.cmd)
 					return
 				}
-			} else if serve.cmd != nil {
-				if serve.r != nil && serve.r.Match(pathBytes) {
-					serveCommand(c, serve.cmd)
+				serveFile(c, request, requestData, path.Join(serve.Root, strippedPath), serve.ListDirectory)
+				return
+			} else if serve.r == nil && strings.HasPrefix(request.Path, serve.Path) {
+				if serve.Proxy != "" {
+					serveProxy(c, requestData, serve.Proxy)
 					return
-				} else if serve.r == nil && strings.HasPrefix(request.Path, serve.Path) {
+				} else if serve.cmd != nil {
 					serveCommand(c, serve.cmd)
 					return
 				}
-			}
-
-			if serve.r != nil && serve.r.Match(pathBytes) {
-				serveFile(c, requestData, path.Join(serve.Root, strippedPath))
-				return
-			} else if serve.r == nil && strings.HasPrefix(request.Path, serve.Path) {
-				serveFile(c, requestData, path.Join(serve.Root, strippedPath[len(serve.Path)-1:]))
+				filePath := request.Path[len(serve.Path):]
+				if len(filePath) > 0 && filePath[0] == '/' {
+					filePath = filePath[1:]
+				}
+				serveFile(c, request, requestData, path.Join(serve.Root, filePath), serve.ListDirectory)
 				return
 			}
 		}

util.go

@@ -0,0 +1,17 @@
+package main
+
+import "fmt"
+
+func formatFileSize(b int64) string {
+	const unit = 1000
+	if b < unit {
+		return fmt.Sprintf("%d B", b)
+	}
+	div, exp := int64(unit), 0
+	for n := b / unit; n >= unit; n /= unit {
+		div *= unit
+		exp++
+	}
+	return fmt.Sprintf("%.0f %cB",
+		float64(b)/float64(div), "KMGTPE"[exp])
+}