squashfs/cmd/go-unsquashfs/main.go

package main

import (
	"flag"
	"fmt"
	"io/fs"
	"os"
	"os/user"
	"path/filepath"
	"strconv"
	"strings"
	"time"

	"github.com/CalebQ42/squashfs"
)

func userName(uid int, numeric bool) string {
	us := strconv.Itoa(uid)
	if numeric {
		return us
	}
	if u, err := user.LookupId(us); err == nil {
		return u.Username
	}
	return us
}

func groupName(gid int, numeric bool) string {
	gs := strconv.Itoa(gid)
	if numeric {
		return gs
	}
	if g, err := user.LookupGroupId(gs); err == nil {
		return g.Name
	}
	return gs
}

func printEntry(path string, d fs.DirEntry, numeric bool) {
	fi, _ := d.Info()
	sfi := fi.(squashfs.FileInfo)
	owner := fmt.Sprintf("%s/%s",
		userName(sfi.Uid(), numeric),
		groupName(sfi.Gid(), numeric))
	link := ""
	if sfi.IsSymlink() {
		link = " -> " + sfi.SymlinkPath()
	}
	fmt.Printf("%s %s %*d %s %s%s\n",
		strings.ToLower(fi.Mode().String()),
		owner, 26-len(owner), fi.Size(),
		fi.ModTime().Format("2006-01-02 15:04"),
		filepath.Join(path), link)
}

func main() {
	verbose := flag.Bool("v", false, "Verbose")
	list := flag.Bool("l", false, "List")
	long := flag.Bool("ll", false, "List with attributes")
	numeric := flag.Bool("lln", false, "List with attributes and numeric ids")
	offset := flag.Int64("o", 0, "Offset")
	ignore := flag.Bool("ip", false, "Ignore Permissions and extract all files/folders with 0755")
	file := flag.String("e", "", "File or folder to extract")
	flag.Parse()
	if (*list || *long || *numeric) && flag.NArg() < 1 {
		fmt.Println("Please provide a file name")
		os.Exit(0)
	} else if (!*list && !*long && !*numeric) && flag.NArg() < 2 {
		fmt.Println("Please provide a file name and extraction path")
		os.Exit(0)
	}
	f, err := os.Open(flag.Arg(0))
	if err != nil {
		panic(err)
	}
	r, err := squashfs.NewReaderAtOffset(f, *offset)
	if err != nil {
		panic(err)
	}
	extractFil := r.File()
	if *file != "" {
		extractFil, err = r.OpenFile(*file)
		if err != nil {
			panic(err)
		}
	}
	if *list || *long || *numeric {
		if extractFil.IsDir() {
			var filFs squashfs.FS
			filFs, err = extractFil.FS()
			if err != nil {
				panic(err)
			}
			err = fs.WalkDir(filFs, ".", func(path string, d fs.DirEntry, err error) error {
				if err != nil {
					panic(err)
				}
				if *long || *numeric {
					printEntry(path, d, *numeric)
				} else {
					fmt.Println(filepath.Clean(path))
				}
				return nil
			})
			if err != nil {
				panic(err)
			}
		}
		return
	}
	op := squashfs.DefaultOptions()
	op.Verbose = *verbose
	op.IgnorePerm = *ignore
	n := time.Now()
	err = extractFil.ExtractWithOptions(flag.Arg(1), op)
	if err != nil {
		panic(err)
	}
	fmt.Println("Took:", time.Since(n))
}