3 files changed, 97 insertions, 1 deletions
diff --git a/steam/filelisting.go b/steam/filelisting.go
new file mode 100644
index 0000000..f94319e
--- /dev/null
+++ b/steam/filelisting.go
@@ -0,0 +1,26 @@
+package steam
+
+import (
+	"path/filepath"
+	"os"
+)
+
+func fileListing(pth string) (map[string]struct{}, error) {
+	out := map[string]struct{}{}
+	err := filepath.Walk(pth, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		if info.Mode().IsRegular() {
+			out[path] = struct{}{}
+		}
+
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return out, nil
+}
diff --git a/steam/package.go b/steam/package.go
index 9000cba..cff086e 100644
--- a/steam/package.go
+++ b/steam/package.go
@@ -26,7 +26,7 @@ func (g *Game) Package(wr io.Writer) error {
 		}
 	}
 
-	return nil
+	return twriter.Flush()
 }
 
 func (l *Library) Extract(r io.Reader) error {
diff --git a/steam/update.go b/steam/update.go
new file mode 100644
index 0000000..b3e621e
--- /dev/null
+++ b/steam/update.go
@@ -0,0 +1,70 @@
+package steam
+
+import (
+	"archive/tar"
+	"io"
+	"os"
+	"strings"
+	"path/filepath"
+)
+
+func (l *Library) ExtractUpdate(r io.Reader) error {
+	if err := os.Chdir(l.Folder); err != nil {
+		return err
+	}
+
+	// withinArchive := map[string]struct{}{}
+	// onDisk, err := fileListing(
+
+	treader := tar.NewReader(r)
+
+	for {
+		hdr, err := treader.Next()
+		if err == io.EOF {
+			// We've reached the end! Whoee
+			break
+		}
+		if err != nil {
+			return err
+		}
+
+		// Fix windows slashes...
+		fileName := strings.Replace(hdr.Name, "\\", "/", -1)
+
+		info := hdr.FileInfo()
+		if info.IsDir() {
+			// I don't like hard-coded permissions but it
+			// it helps with overall platform compatibility
+			if err = os.MkdirAll(fileName, 0775); err != nil {
+				return err
+			}
+			continue
+		}
+
+		if err = os.MkdirAll(filepath.Dir(fileName), 0775); err != nil {
+			return err
+		}
+
+		fi, err := os.Stat(fileName)
+		if !os.IsNotExist(err) {
+			// If the file in the archive is not newer, skip
+			if !info.ModTime().After(fi.ModTime()) {
+				continue
+			}
+		}
+
+		// Create a file handle to work with
+		f, err := os.OpenFile(fileName, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0664)
+		if err != nil {
+			return err
+		}
+		if _, err := io.Copy(f, treader); err != nil {
+			return err
+		}
+		f.Close()
+
+	}
+
+	return nil
+}
+