Added Reader.ModTime

Haven't implemented LZO due to limited libraries

README.md

@@ -1,14 +1,14 @@
-# squashfs [![PkgGoDev](https://pkg.go.dev/badge/github.com/CalebQ42/squashfs)](https://pkg.go.dev/github.com/CalebQ42/squashfs)
+# squashfs (WIP)
+
+[![PkgGoDev](https://pkg.go.dev/badge/github.com/CalebQ42/squashfs)](https://pkg.go.dev/github.com/CalebQ42/squashfs) [![Go Report Card](https://goreportcard.com/badge/github.com/CalebQ42/squashfs)](https://goreportcard.com/report/github.com/CalebQ42/squashfs)
 
 A PURE Go library to read and write squashfs.
 
-Currently, you can read a squashfs and extract files (folder extraction not supported. Yet).
+Currently has support for reading squashfs files and extracting files and folders. Supports all compression types except LZO, but additional compression options are hit or miss.
+
+The only major thing missing from squashfs reading is Xattr parsing.
 
 Special thanks to https://dr-emann.github.io/squashfs/ for some VERY important information in an easy to understand format.
 Thanks also to [distri's squashfs library](https://github.com/distr1/distri/tree/master/internal/squashfs) as I referenced it to figure some things out (and double check others).
 
-# [TODO](https://github.com/CalebQ42/squashfs/projects/1?fullscreen=true)
-
-# Where I'm at
-
-* Working on the File interface that should make it easier to deal with squashfs files. I'm also trying to make them capable for when I get squashing working.
+# [TODO](https://github.com/CalebQ42/squashfs/projects/1?fullscreen=true)

file.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"path"
 	"strings"
+	"time"
 
 	"github.com/CalebQ42/squashfs/internal/directory"
 	"github.com/CalebQ42/squashfs/internal/inode"
@@ -26,10 +27,12 @@ var (
 //File is the main way to interact with files within squashfs, or when putting files into a squashfs.
 //File can be either a file or folder. When reading from a squashfs, it reads from the datablocks.
 //When writing, this holds the information on WHERE the file will be placed inside the archive.
+//
+//Implements os.FileInfo and io.ReadCloser
 type File struct {
-	Name    string       //The name of the file or folder. Root folder will not have a name ("")
 	Parent  *File        //The parent directory. Should ALWAYS be a folder. If it's the root directory, will be nil
 	Reader  io.Reader    //Underlying reader. When writing, will probably be an os.File. When reading this is kept nil UNTIL reading to save memory.
+	name    string       //The name of the file or folder. Root folder will not have a name ("")
 	path    string       //The path to the folder the File is located in.
 	r       *Reader      //The squashfs.Reader where this file is contained.
 	in      *inode.Inode //Underlyting inode when reading.
@@ -43,12 +46,50 @@ func (r *Reader) newFileFromDirEntry(entry *directory.Entry) (fil *File, err err
 	if err != nil {
 		return nil, err
 	}
-	fil.Name = entry.Name
+	fil.name = entry.Name
 	fil.r = r
 	fil.filType = fil.in.Type
 	return
 }
 
+//Name is the file's name
+func (f *File) Name() string {
+	return f.name
+}
+
+//Size is the complete size of the file. Zero if it's not a file.
+func (f *File) Size() int64 {
+	switch f.filType {
+	case inode.BasicFileType:
+		return int64(f.in.Info.(inode.BasicFile).Init.Size)
+	case inode.ExtFileType:
+		return int64(f.in.Info.(inode.ExtendedFile).Init.Size)
+	default:
+		return 0
+	}
+}
+
+//ModTime is the time of last modification.
+func (f *File) ModTime() time.Time {
+	return time.Unix(int64(f.in.Header.ModifiedTime), 0)
+}
+
+//Sys returns the underlying reader, file.Reader. If the reader isn't initialized, it will initialize it.
+//If called on something other then a file, returns nil.
+func (f *File) Sys() interface{} {
+	if f.IsFile() {
+		if f.Reader == nil && f.r != nil {
+			var err error
+			f.Reader, err = f.r.newFileReader(f.in)
+			if err != nil {
+				return nil
+			}
+		}
+		return f.Reader
+	}
+	return nil
+}
+
 //GetChildren returns a *squashfs.File slice of every direct child of the directory. If the File is not a directory, will return ErrNotDirectory
 func (f *File) GetChildren() (children []*File, err error) {
 	children = make([]*File, 0)
@@ -69,7 +110,7 @@ func (f *File) GetChildren() (children []*File, err error) {
 			return
 		}
 		fil.Parent = f
-		if f.Name != "" {
+		if f.name != "" {
 			fil.path = f.Path()
 		}
 		children = append(children, fil)
@@ -117,10 +158,10 @@ func (f *File) GetChildrenRecursively() (children []*File, err error) {
 
 //Path returns the path of the file within the archive.
 func (f *File) Path() string {
-	if f.Name == "" {
+	if f.name == "" {
 		return f.path
 	}
-	return f.path + "/" + f.Name
+	return f.path + "/" + f.name
 }
 
 //GetFileAtPath tries to return the File at the given path, relative to the file.
@@ -139,7 +180,7 @@ func (f *File) GetFileAtPath(dirPath string) *File {
 		dirPath = strings.TrimPrefix(dirPath, "./")
 	}
 	split := strings.Split(dirPath, "/")
-	if split[0] == ".." && f.Name == "" {
+	if split[0] == ".." && f.name == "" {
 		return nil
 	} else if split[0] == ".." {
 		if f.Parent != nil {
@@ -152,7 +193,7 @@ func (f *File) GetFileAtPath(dirPath string) *File {
 		return nil
 	}
 	for _, child := range children {
-		eq, _ := path.Match(split[0], child.Name)
+		eq, _ := path.Match(split[0], child.name)
 		if eq {
 			return child.GetFileAtPath(strings.Join(split[1:], "/"))
 		}
@@ -199,8 +240,8 @@ func (f *File) GetSymlinkFile() *File {
 	return f.r.GetFileAtPath(f.SymlinkPath())
 }
 
-//Permission returns the os.FileMode of the File. Sets mode bits for directories and symlinks.
-func (f *File) Permission() os.FileMode {
+//Mode returns the os.FileMode of the File. Sets mode bits for directories and symlinks.
+func (f *File) Mode() os.FileMode {
 	mode := os.FileMode(f.in.Header.Permissions)
 	switch {
 	case f.IsDir():
@@ -244,21 +285,21 @@ func (f *File) ExtractWithOptions(path string, dereferenceSymlink, unbreakSymlin
 	}
 	switch {
 	case f.IsDir():
-		if f.Name != "" {
+		if f.name != "" {
 			//TODO: check if folder is present, and if so, try to set it's permission
-			err = os.Mkdir(path+"/"+f.Name, os.ModePerm)
+			err = os.Mkdir(path+"/"+f.name, os.ModePerm)
 			if err != nil {
 				if verbose {
-					fmt.Println("Error while making: ", path+"/"+f.Name)
+					fmt.Println("Error while making: ", path+"/"+f.name)
 					fmt.Println(err)
 				}
 				errs = append(errs, err)
 				return
 			}
-			fil, err := os.Open(path + "/" + f.Name)
+			fil, err := os.Open(path + "/" + f.name)
 			if err != nil {
 				if verbose {
-					fmt.Println("Error while opening:", path+"/"+f.Name)
+					fmt.Println("Error while opening:", path+"/"+f.name)
 					fmt.Println(err)
 				}
 				errs = append(errs, err)
@@ -273,10 +314,10 @@ func (f *File) ExtractWithOptions(path string, dereferenceSymlink, unbreakSymlin
 			// 	}
 			// 	errs = append(errs, err)
 			// }
-			err = fil.Chmod(f.Permission())
+			err = fil.Chmod(f.Mode())
 			if err != nil {
 				if verbose {
-					fmt.Println("Error while changing owner:", path+"/"+f.Name)
+					fmt.Println("Error while changing owner:", path+"/"+f.name)
 					fmt.Println(err)
 				}
 				errs = append(errs, err)
@@ -295,10 +336,10 @@ func (f *File) ExtractWithOptions(path string, dereferenceSymlink, unbreakSymlin
 		defer close(finishChan)
 		for _, child := range children {
 			go func(child *File) {
-				if f.Name == "" {
+				if f.name == "" {
 					finishChan <- child.ExtractWithOptions(path, dereferenceSymlink, unbreakSymlink, folderPerm, verbose)
 				} else {
-					finishChan <- child.ExtractWithOptions(path+"/"+f.Name, dereferenceSymlink, unbreakSymlink, folderPerm, verbose)
+					finishChan <- child.ExtractWithOptions(path+"/"+f.name, dereferenceSymlink, unbreakSymlink, folderPerm, verbose)
 				}
 			}(child)
 		}
@@ -307,21 +348,21 @@ func (f *File) ExtractWithOptions(path string, dereferenceSymlink, unbreakSymlin
 		}
 		return
 	case f.IsFile():
-		fil, err := os.Create(path + "/" + f.Name)
+		fil, err := os.Create(path + "/" + f.name)
 		if os.IsExist(err) {
-			err = os.Remove(path + "/" + f.Name)
+			err = os.Remove(path + "/" + f.name)
 			if err != nil {
 				if verbose {
-					fmt.Println("Error while making:", path+"/"+f.Name)
+					fmt.Println("Error while making:", path+"/"+f.name)
 					fmt.Println(err)
 				}
 				errs = append(errs, err)
 				return
 			}
-			fil, err = os.Create(path + "/" + f.Name)
+			fil, err = os.Create(path + "/" + f.name)
 			if err != nil {
 				if verbose {
-					fmt.Println("Error while making:", path+"/"+f.Name)
+					fmt.Println("Error while making:", path+"/"+f.name)
 					fmt.Println(err)
 				}
 				errs = append(errs, err)
@@ -329,7 +370,7 @@ func (f *File) ExtractWithOptions(path string, dereferenceSymlink, unbreakSymlin
 			}
 		} else if err != nil {
 			if verbose {
-				fmt.Println("Error while making:", path+"/"+f.Name)
+				fmt.Println("Error while making:", path+"/"+f.name)
 				fmt.Println(err)
 			}
 			errs = append(errs, err)
@@ -338,7 +379,7 @@ func (f *File) ExtractWithOptions(path string, dereferenceSymlink, unbreakSymlin
 		_, err = io.Copy(fil, f)
 		if err != nil {
 			if verbose {
-				fmt.Println("Error while Copying data to:", path+"/"+f.Name)
+				fmt.Println("Error while Copying data to:", path+"/"+f.name)
 				fmt.Println(err)
 			}
 			errs = append(errs, err)
@@ -355,10 +396,10 @@ func (f *File) ExtractWithOptions(path string, dereferenceSymlink, unbreakSymlin
 		// 	errs = append(errs, err)
 		// 	return
 		// }
-		err = fil.Chmod(f.Permission())
+		err = fil.Chmod(f.Mode())
 		if err != nil {
 			if verbose {
-				fmt.Println("Error while setting permissions for:", path+"/"+f.Name)
+				fmt.Println("Error while setting permissions for:", path+"/"+f.name)
 				fmt.Println(err)
 			}
 			errs = append(errs, err)
@@ -370,15 +411,15 @@ func (f *File) ExtractWithOptions(path string, dereferenceSymlink, unbreakSymlin
 			fil := f.GetSymlinkFile()
 			if fil == nil {
 				if verbose {
-					fmt.Println("Symlink path(", symPath, ") is outside the archive:"+path+"/"+f.Name)
+					fmt.Println("Symlink path(", symPath, ") is outside the archive:"+path+"/"+f.name)
 				}
 				return
 			}
-			fil.Name = f.Name
+			fil.name = f.name
 			extracSymErrs := fil.ExtractWithOptions(path, dereferenceSymlink, unbreakSymlink, folderPerm, verbose)
 			if len(extracSymErrs) > 0 {
 				if verbose {
-					fmt.Println("Error(s) while extracting the symlink's file:", path+"/"+f.Name)
+					fmt.Println("Error(s) while extracting the symlink's file:", path+"/"+f.name)
 					fmt.Println(extracSymErrs)
 				}
 				errs = append(errs, extracSymErrs...)
@@ -392,22 +433,22 @@ func (f *File) ExtractWithOptions(path string, dereferenceSymlink, unbreakSymlin
 				extracSymErrs := fil.ExtractWithOptions(strings.Join(paths[:len(paths)-1], "/"), dereferenceSymlink, unbreakSymlink, folderPerm, verbose)
 				if len(extracSymErrs) > 0 {
 					if verbose {
-						fmt.Println("Error(s) while extracting the symlink's file:", path+"/"+f.Name)
+						fmt.Println("Error(s) while extracting the symlink's file:", path+"/"+f.name)
 						fmt.Println(extracSymErrs)
 					}
 					errs = append(errs, extracSymErrs...)
 				}
 			} else {
 				if verbose {
-					fmt.Println("Symlink path(", symPath, ") is outside the archive:"+path+"/"+f.Name)
+					fmt.Println("Symlink path(", symPath, ") is outside the archive:"+path+"/"+f.name)
 				}
 				return
 			}
 		}
-		err = os.Symlink(f.SymlinkPath(), path+"/"+f.Name)
+		err = os.Symlink(f.SymlinkPath(), path+"/"+f.name)
 		if err != nil {
 			if verbose {
-				fmt.Println("Error while making symlink:", path+"/"+f.Name)
+				fmt.Println("Error while making symlink:", path+"/"+f.name)
 				fmt.Println(err)
 			}
 			errs = append(errs, err)

go.mod

@@ -7,7 +7,9 @@ require (
 	github.com/adrg/xdg v0.2.3 // indirect
 	github.com/google/go-cmp v0.5.4 // indirect
 	github.com/gopherjs/gopherjs v0.0.0-20200217142428-fce0ec30dd00 // indirect
+	github.com/klauspost/compress v1.11.3
 	github.com/kr/text v0.2.0 // indirect
+	github.com/pierrec/lz4/v4 v4.1.1
 	github.com/smartystreets/assertions v1.2.0 // indirect
 	github.com/ulikunitz/xz v0.5.8
 	golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 // indirect

go.sum

@@ -18,6 +18,8 @@ github.com/gopherjs/gopherjs v0.0.0-20200217142428-fce0ec30dd00 h1:l5lAOZEym3oK3
 github.com/gopherjs/gopherjs v0.0.0-20200217142428-fce0ec30dd00/go.mod h1:wJfORRmW1u3UXTncJ5qlYoELFm8eSnnEO6hX4iZ3EWY=
 github.com/jtolds/gls v4.20.0+incompatible h1:xdiiI2gbIgH/gLH7ADydsJ1uDOEzR8yvV7C0MuV77Wo=
 github.com/jtolds/gls v4.20.0+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=
+github.com/klauspost/compress v1.11.3 h1:dB4Bn0tN3wdCzQxnS8r06kV74qN/TAfaIS0bVE8h3jc=
+github.com/klauspost/compress v1.11.3/go.mod h1:aoV0uJVorq1K+umq18yTdKaF57EivdYsUV+/s2qKfXs=
 github.com/kr/pretty v0.2.1 h1:Fmg33tUaq4/8ym9TJN1x7sLJnHVwhP33CNkpYV/7rwI=
 github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
@@ -27,6 +29,8 @@ github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e h1:fD57ERR4JtEqsWbfPhv4DMiApHyliiK5xCTNVSPiaAs=
 github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
+github.com/pierrec/lz4/v4 v4.1.1 h1:cS6aGkNLJr4u+UwaA21yp+gbWN3WJWtKo1axmPDObMA=
+github.com/pierrec/lz4/v4 v4.1.1/go.mod h1:gZWDp/Ze/IJXGXf23ltt2EXimqmTUXEy0GFuRQyBid4=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d h1:zE9ykElWQ6/NYmHa3jpm/yHnI4xSofP+UP6SpjHcSeM=

internal/compression/gzip.go

@@ -3,11 +3,37 @@ package compression
 import (
 	"bytes"
 	"compress/zlib"
+	"encoding/binary"
 	"io"
 )
 
+type gzipInit struct {
+	CompressionLevel int32
+	WindowSize       int16
+	Strategies       int16
+}
+
 //Gzip is a decompressor for gzip type compression. Uses zlib for compression and decompression
-type Gzip struct{}
+type Gzip struct {
+	CompressionLevel int32
+	HasCustomWindow  bool
+	HasStrategies    bool
+}
+
+//NewGzipCompressorWithOptions creates a new gzip compressor/decompressor with options read from the given reader.
+func NewGzipCompressorWithOptions(r io.Reader) (*Gzip, error) {
+	var gzip Gzip
+	var init gzipInit
+	err := binary.Read(r, binary.LittleEndian, &init)
+	if err != nil {
+		return nil, err
+	}
+	gzip.CompressionLevel = init.CompressionLevel
+	//TODO: proper support for window size and strategies
+	gzip.HasCustomWindow = init.WindowSize != 15
+	gzip.HasStrategies = init.Strategies != 0 && init.Strategies != 1
+	return &gzip, nil
+}
 
 //Decompress reads the entirety of the given reader and returns it uncompressed as a byte slice.
 func (g *Gzip) Decompress(r io.Reader) ([]byte, error) {

internal/compression/lz4.go

@@ -0,0 +1,37 @@
+package compression
+
+import (
+	"bytes"
+	"encoding/binary"
+	"io"
+
+	"github.com/pierrec/lz4/v4"
+)
+
+//Lz4 is a Lz4 Compressor/Decompressor
+type Lz4 struct {
+	HC bool
+}
+
+//NewLz4CompressorWithOptions creates a new lz4 compressor/decompressor with options read from the given reader.
+func NewLz4CompressorWithOptions(r io.Reader) (*Lz4, error) {
+	var lz4 Lz4
+	var init struct {
+		Version int32
+		Flags   int32
+	}
+	err := binary.Read(r, binary.LittleEndian, &init)
+	if err != nil {
+		return nil, err
+	}
+	lz4.HC = init.Flags == 1
+	return &lz4, nil
+}
+
+//Decompress decompresses all data from r and returns the uncompressed bytes
+func (l *Lz4) Decompress(r io.Reader) ([]byte, error) {
+	rdr := lz4.NewReader(r)
+	var buf bytes.Buffer
+	_, err := io.Copy(&buf, rdr)
+	return buf.Bytes(), err
+}

internal/compression/zstd.go

@@ -0,0 +1,36 @@
+package compression
+
+import (
+	"bytes"
+	"encoding/binary"
+	"io"
+
+	"github.com/klauspost/compress/zstd"
+)
+
+//Zstd is a zstd compressor/decompressor
+type Zstd struct {
+	CompressionLevel int32
+}
+
+//NewZstdCompressorWithOptions creates a new Zstd with options read from the given reader
+func NewZstdCompressorWithOptions(r io.Reader) (*Zstd, error) {
+	var zstd Zstd
+	err := binary.Read(r, binary.LittleEndian, &zstd)
+	if err != nil {
+		return nil, err
+	}
+	return &zstd, nil
+}
+
+//Decompress decompresses all data from the reader and returns the uncompressed data
+func (z *Zstd) Decompress(r io.Reader) ([]byte, error) {
+	rdr, err := zstd.NewReader(r)
+	if err != nil {
+		return nil, err
+	}
+	defer rdr.Close()
+	var buf bytes.Buffer
+	_, err = io.Copy(&buf, rdr)
+	return buf.Bytes(), err
+}

reader.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"io"
 	"math"
+	"time"
 
 	"github.com/CalebQ42/squashfs/internal/compression"
 	"github.com/CalebQ42/squashfs/internal/inode"
@@ -21,6 +22,8 @@ var (
 	errIncompatibleCompression = errors.New("Compression type unsupported")
 	//ErrCompressorOptions is returned if compressor options is present. It's not currently supported.
 	errCompressorOptions = errors.New("Compressor options is not currently supported")
+	//ErrOptions is returned when compression options that I haven't tested is set. When this is returned, the Reader is also returned.
+	ErrOptions = errors.New("Possibly incompatible compressor options")
 )
 
 //Reader processes and reads a squashfs archive.
@@ -35,6 +38,7 @@ type Reader struct {
 
 //NewSquashfsReader returns a new squashfs.Reader from an io.ReaderAt
 func NewSquashfsReader(r io.ReaderAt) (*Reader, error) {
+	hasUnsupportedOptions := false
 	var rdr Reader
 	rdr.r = r
 	err := binary.Read(io.NewSectionReader(rdr.r, 0, int64(binary.Size(rdr.super))), binary.LittleEndian, &rdr.super)
@@ -50,8 +54,17 @@ func NewSquashfsReader(r io.ReaderAt) (*Reader, error) {
 	rdr.flags = rdr.super.GetFlags()
 	if rdr.flags.CompressorOptions {
 		switch rdr.super.CompressionType {
+		case gzipCompression:
+			gzip, err := compression.NewGzipCompressorWithOptions(io.NewSectionReader(rdr.r, int64(binary.Size(rdr.super)), 8))
+			if err != nil {
+				return nil, err
+			}
+			if gzip.HasCustomWindow || gzip.HasStrategies {
+				hasUnsupportedOptions = true
+			}
+			rdr.decompressor = gzip
 		case xzCompression:
-			xz, err := compression.NewXzCompressorWithOptions(io.NewSectionReader(rdr.r, int64(binary.Size(rdr.super)), 1000)) //1000 is technically too much, but it's just an easy way to do it.
+			xz, err := compression.NewXzCompressorWithOptions(io.NewSectionReader(rdr.r, int64(binary.Size(rdr.super)), 8))
 			if err != nil {
 				return nil, err
 			}
@@ -59,6 +72,21 @@ func NewSquashfsReader(r io.ReaderAt) (*Reader, error) {
 				return nil, errors.New("XZ compression options has filters. These are not yet supported")
 			}
 			rdr.decompressor = xz
+		case lz4Compression:
+			lz4, err := compression.NewLz4CompressorWithOptions(io.NewSectionReader(rdr.r, int64(binary.Size(rdr.super)), 8))
+			if err != nil {
+				return nil, err
+			}
+			if lz4.HC {
+				hasUnsupportedOptions = true
+			}
+			rdr.decompressor = lz4
+		case zstdCompression:
+			zstd, err := compression.NewZstdCompressorWithOptions(io.NewSectionReader(rdr.r, int64(binary.Size(rdr.super)), 4))
+			if err != nil {
+				return nil, err
+			}
+			rdr.decompressor = zstd
 		default:
 			return nil, errCompressorOptions
 		}
@@ -70,6 +98,10 @@ func NewSquashfsReader(r io.ReaderAt) (*Reader, error) {
 			rdr.decompressor = &compression.Lzma{}
 		case xzCompression:
 			rdr.decompressor = &compression.Xz{}
+		case lz4Compression:
+			rdr.decompressor = &compression.Lz4{}
+		case zstdCompression:
+			rdr.decompressor = &compression.Zstd{}
 		default:
 			//TODO: all compression types.
 			return nil, errIncompatibleCompression
@@ -111,9 +143,26 @@ func NewSquashfsReader(r io.ReaderAt) (*Reader, error) {
 		}
 		unread -= read
 	}
+	if hasUnsupportedOptions {
+		return &rdr, ErrOptions
+	}
 	return &rdr, nil
 }
 
+//ModTime is the last time the file was modified/created.
+func (r *Reader) ModTime() time.Time {
+	return time.Unix(int64(r.super.CreationTime), 0)
+}
+
+//ExtractTo tries to extract ALL files to the given path. This is the same as getting the root folder and extracting that.
+func (r *Reader) ExtractTo(path string) []error {
+	root, err := r.GetRootFolder()
+	if err != nil {
+		return []error{err}
+	}
+	return root.ExtractTo(path)
+}
+
 //GetRootFolder returns a squashfs.File that references the root directory of the squashfs archive.
 func (r *Reader) GetRootFolder() (root *File, err error) {
 	root = new(File)

squash_test.go

@@ -15,7 +15,7 @@ const (
 	squashfsName = "airootfs.sfs" //testing with a ArchLinux root fs from the live img
 )
 
-//Right now, don't use. Arch linux sfs uses XZ compression and when tested, most files just completely fail to extract.
+//Right now, don't use. Arch linux sfs uses XZ compression with filters, which isn't supported
 func TestSquashfs(t *testing.T) {
 	wd, err := os.Getwd()
 	if err != nil {
@@ -58,11 +58,7 @@ func TestAppImage(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	fil := rdr.GetFileAtPath(".DirIcon")
-	if fil == nil {
-		t.Fatal("Can't find desktop file")
-	}
-	errs := fil.ExtractSymlink(wd + "/testing/")
+	errs := rdr.ExtractTo(wd + "/testing/cool-retro")
 	if len(errs) > 0 {
 		t.Fatal(errs)
 	}
@@ -74,8 +70,8 @@ func TestAppImage(t *testing.T) {
 }
 
 func downloadTestAppImage(t *testing.T, dir string) {
-	//seems to time out on slow connections. Might fix that at some point... or not
-	os.Mkdir(dir, 0777)
+	//seems to time out on slow connections. Might fix that at some point... or not. It's just a test...
+	os.Mkdir(dir, os.ModePerm)
 	appImage, err := os.Create(dir + "/" + appImageName)
 	if err != nil {
 		t.Fatal(err)