init

cmd/asar/main.go

@@ -0,0 +1,97 @@
+package main // import "b612.me/cmd/asar"
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"b612.me/asar"
+)
+
+func main() {
+	flag.Usage = func() {
+		fmt.Fprintf(os.Stderr, "usage: %s [options] [command]\n", os.Args[0])
+		fmt.Fprintf(os.Stderr, "Commands:\n")
+		fmt.Fprintf(os.Stderr, "\n")
+		fmt.Fprintf(os.Stderr, "  l|list <archive>\n")
+		fmt.Fprintf(os.Stderr, "    list contents of asar archive\n")
+		fmt.Fprintf(os.Stderr, "  x|extract <archive> <dir>\n")
+		fmt.Fprintf(os.Stderr, "    extract contents of asar archive to directory\n")
+		fmt.Fprintf(os.Stderr, "\n")
+		flag.PrintDefaults()
+	}
+	flag.Parse()
+
+	if flag.NArg() < 2 {
+		flag.Usage()
+		os.Exit(3)
+	}
+
+	file, err := os.Open(flag.Arg(1))
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "asar: %s\n", err)
+		os.Exit(1)
+	}
+	defer file.Close()
+
+	root, err := asar.Decode(file)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "asar: %s\n", err)
+		os.Exit(1)
+	}
+
+	switch command := flag.Arg(0); command {
+	case "l", "list":
+		root.Walk(func(path string, _ os.FileInfo, _ error) error {
+			fmt.Println("/" + path)
+			return nil
+		})
+
+	case "x", "extract":
+		if flag.NArg() < 3 {
+			flag.Usage()
+			os.Exit(1)
+		}
+
+		target := flag.Arg(2)
+
+		err := root.Walk(func(path string, info os.FileInfo, _ error) error {
+			entry := info.Sys().(*asar.Entry)
+
+			realPath := filepath.Join(target, path)
+			if entry.Flags&asar.FlagDir != 0 {
+				return os.MkdirAll(realPath, 0755)
+			}
+			if entry.Flags&asar.FlagUnpacked != 0 {
+				return nil
+			}
+
+			perm := os.FileMode(0644)
+			if entry.Flags&asar.FlagExecutable != 0 {
+				perm |= 0111
+			}
+
+			f, err := os.OpenFile(realPath, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, perm)
+			if err != nil {
+				return err
+			}
+
+			_, err = entry.WriteTo(f)
+			if err != nil {
+				f.Close()
+				return err
+			}
+
+			if err := f.Close(); err != nil {
+				return err
+			}
+
+			return nil
+		})
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "asar: %s\n", err)
+			os.Exit(1)
+		}
+	}
+}