1 files changed, 83 insertions, 0 deletions
diff --git a/filesystem/path.go b/filesystem/path.go
new file mode 100644
index 0000000..3be1859
--- /dev/null
+++ b/filesystem/path.go
@@ -0,0 +1,83 @@
+/*
+ * path.go - Utility functions for dealing with filesystem paths
+ *
+ * Copyright 2017 Google Inc.
+ * Author: Joe Richey (joerichey@google.com)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+
+package filesystem
+
+import (
+	"log"
+	"os"
+	"path/filepath"
+)
+
+// We only check the unix permissions and the sticky bit
+const permMask = os.ModeSticky | os.ModePerm
+
+// cannonicalizePath turns path into an absolute path without symlinks.
+func cannonicalizePath(path string) (string, error) {
+	path, err := filepath.Abs(path)
+	if err != nil {
+		return "", err
+	}
+
+	return filepath.EvalSymlinks(path)
+}
+
+// loggedStat runs os.Stat, but it logs the error if stat returns any error
+// other than nil or IsNotExist.
+func loggedStat(name string) (os.FileInfo, error) {
+	info, err := os.Stat(name)
+	if err != nil && !os.IsNotExist(err) {
+		log.Print(err)
+	}
+	return info, err
+}
+
+// isDir returns true if the path exists and is that of a directory.
+func isDir(path string) bool {
+	info, err := loggedStat(path)
+	return err == nil && info.IsDir()
+}
+
+// isDevice returns true if the path exists and is that of a directory.
+func isDevice(path string) bool {
+	info, err := loggedStat(path)
+	return err == nil && info.Mode()&os.ModeDevice != 0
+}
+
+// isDirCheckPerm returns true if the path exists and is a directory. If the
+// specified permissions and sticky bit of mode do not match the path, and error
+// is logged.
+func isDirCheckPerm(path string, mode os.FileMode) bool {
+	info, err := loggedStat(path)
+	// Check if directory
+	if err != nil || !info.IsDir() {
+		return false
+	}
+	// Check for bad permissions
+	if info.Mode()&permMask != mode&permMask {
+		log.Printf("directory %s has incorrect permissions", path)
+	}
+	return true
+}
+
+// isRegularFile returns true if the path exists and is that of a regular file.
+func isRegularFile(path string) bool {
+	info, err := loggedStat(path)
+	return err == nil && info.Mode().IsRegular()
+}