Initial implementation for .desktop fuse fs

dot-desktop-fuse/main.go

@@ -0,0 +1,84 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"io/ioutil"
+	"log"
+	"os"
+	"os/signal"
+	"path/filepath"
+	"regexp"
+	"syscall"
+
+	"github.com/hanwen/go-fuse/v2/fs"
+	"github.com/hanwen/go-fuse/v2/fuse"
+)
+
+type ddf struct {
+	Path string
+	fs.Inode
+}
+
+func (r *ddf) OnAdd(ctx context.Context) {
+	files, err := ioutil.ReadDir(r.Path)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	for _, file := range files {
+		b, err := ioutil.ReadFile(filepath.Join(r.Path, file.Name()))
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		b = bytes.ReplaceAll(b, []byte("Actions="), []byte("Actions=appvm;"))
+
+		raw := string(regexp.MustCompile("Exec=[a-zA-Z0-9]*").Find(b))
+
+		var app string
+		if len(raw) > 5 {
+			app = string(raw)[5:]
+		} else {
+			log.Println("Can't find Exec entry for", file.Name())
+			continue
+		}
+
+		b = append(b, []byte("\n[Desktop Action appvm]\n")...)
+		b = append(b, []byte("Name=Open in appvm\n")...)
+		b = append(b, []byte("Exec=appvm start "+app+"\n")...)
+
+		ch := r.NewPersistentInode(
+			ctx, &fs.MemRegularFile{
+				Data: b,
+				Attr: fuse.Attr{Mode: 0444},
+			}, fs.StableAttr{})
+		r.AddChild(file.Name(), ch, false)
+	}
+}
+
+var _ = (fs.NodeOnAdder)((*ddf)(nil))
+
+func setupSigintHandler(server *fuse.Server) {
+	c := make(chan os.Signal)
+	signal.Notify(c, os.Interrupt, syscall.SIGTERM)
+	go func() {
+		<-c
+		server.Unmount()
+		os.Exit(1)
+	}()
+}
+
+func main() {
+	const from = "/var/run/current-system/sw/share/applications/"
+
+	to := filepath.Join(os.Getenv("HOME"), "/.local/share/applications")
+	os.MkdirAll(to, 0755)
+
+	server, err := fs.Mount(to, &ddf{Path: from}, nil)
+	if err != nil {
+		log.Fatal(err)
+	}
+	setupSigintHandler(server)
+	server.Wait()
+}