New upstream version 1.0.0+git20171222.87b0d5e

1 files changed, 105 insertions, 0 deletions

diff --git a/filesystem.go b/filesystem.go
new file mode 100644
index 0000000..a6e5239
--- /dev/null
+++ b/filesystem.go
@@ -0,0 +1,105 @@
+package debos
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"os"
+	"path"
+	"path/filepath"
+	"strings"
+)
+
+func CleanPathAt(path, at string) string {
+	if filepath.IsAbs(path) {
+		return filepath.Clean(path)
+	}
+
+	return filepath.Join(at, path)
+}
+
+func CleanPath(path string) string {
+	cwd, _ := os.Getwd()
+	return CleanPathAt(path, cwd)
+}
+
+func CopyFile(src, dst string, mode os.FileMode) error {
+	in, err := os.Open(src)
+	if err != nil {
+		return err
+	}
+	defer in.Close()
+	tmp, err := ioutil.TempFile(filepath.Dir(dst), "")
+	if err != nil {
+		return err
+	}
+	_, err = io.Copy(tmp, in)
+	if err != nil {
+		tmp.Close()
+		os.Remove(tmp.Name())
+		return err
+	}
+	if err = tmp.Close(); err != nil {
+		os.Remove(tmp.Name())
+		return err
+	}
+	if err = os.Chmod(tmp.Name(), mode); err != nil {
+		os.Remove(tmp.Name())
+		return err
+	}
+	return os.Rename(tmp.Name(), dst)
+}
+
+func CopyTree(sourcetree, desttree string) error {
+	fmt.Printf("Overlaying %s on %s\n", sourcetree, desttree)
+	walker := func(p string, info os.FileInfo, err error) error {
+
+		if err != nil {
+			return err
+		}
+
+		suffix, _ := filepath.Rel(sourcetree, p)
+		target := path.Join(desttree, suffix)
+		switch info.Mode() & os.ModeType {
+		case 0:
+			CopyFile(p, target, info.Mode())
+		case os.ModeDir:
+			os.Mkdir(target, info.Mode())
+		case os.ModeSymlink:
+			link, err := os.Readlink(p)
+			if err != nil {
+				log.Panicf("Failed to read symlink %s: %v", suffix, err)
+			}
+			os.Symlink(link, target)
+		default:
+			log.Panicf("Not handled /%s %v", suffix, info.Mode())
+		}
+
+		return nil
+	}
+
+	return filepath.Walk(sourcetree, walker)
+}
+
+func RealPath(path string) (string, error) {
+	p, err := filepath.EvalSymlinks(path)
+	if err != nil {
+		return "", err
+	}
+
+	return filepath.Abs(p)
+}
+
+func RestrictedPath(prefix, dest string) (string, error) {
+	var err error
+	destination := path.Join(prefix, dest)
+	destination, err = filepath.Abs(destination)
+	if err != nil {
+		return "", err
+	}
+	if !strings.HasPrefix(destination, prefix) {
+		return "", fmt.Errorf("The resulting path points outside of prefix '%s': '%s'\n", prefix, destination)
+	}
+	return destination, nil
+}