os: MkdirAll, RemoveAll, Chmod, Chown, Truncate, Getgroups.
Getuid, etc drop their errors -- they cannot error
R=r
DELTA=605 (547 added, 12 deleted, 46 changed)
OCL=28919
CL=28929
diff --git a/src/lib/os/path.go b/src/lib/os/path.go
new file mode 100644
index 0000000..0b86b8f
--- /dev/null
+++ b/src/lib/os/path.go
@@ -0,0 +1,121 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package os
+
+import "os"
+
+// PathError reports an error and the file path where it occurred.
+type PathError struct {
+ Path string;
+ Error Error;
+}
+
+func (p *PathError) String() string {
+ return p.Path + ": " + p.Error.String();
+}
+
+// MkdirAll creates a directory named path,
+// along with any necessary parents, and returns nil,
+// or else returns an error.
+// The permission bits perm are used for all
+// directories that MkdirAll creates.
+// If path is already a directory, MkdirAll does nothing
+// and returns nil.
+func MkdirAll(path string, perm int) Error {
+ // If path exists, stop with success or error.
+ dir, err := os.Lstat(path);
+ if err == nil {
+ if dir.IsDirectory() {
+ return nil;
+ }
+ return &PathError{path, ENOTDIR};
+ }
+
+ // Doesn't already exist; make sure parent does.
+ i := len(path);
+ for i > 0 && path[i-1] == '/' { // Skip trailing slashes.
+ i--;
+ }
+
+ j := i;
+ for j > 0 && path[j-1] != '/' { // Scan backward over element.
+ j--;
+ }
+
+ if j > 0 {
+ // Create parent
+ err = MkdirAll(path[0:j-1], perm);
+ if err != nil {
+ return err;
+ }
+ }
+
+ // Now parent exists, try to create.
+ err = Mkdir(path, perm);
+ if err != nil {
+ // Handle arguments like "foo/." by
+ // double-checking that directory doesn't exist.
+ dir, err1 := os.Lstat(path);
+ if err1 == nil && dir.IsDirectory() {
+ return nil;
+ }
+ return &PathError{path, err};
+ }
+ return nil;
+}
+
+// RemoveAll removes path and any children it contains.
+// It removes everything it can but returns the first error
+// it encounters.
+func RemoveAll(path string) Error {
+ // Simple case: if Remove works, we're done.
+ err := Remove(path);
+ if err == nil {
+ return nil;
+ }
+
+ // Otherwise, is this a directory we need to recurse into?
+ dir, err1 := os.Lstat(path);
+ if err1 != nil {
+ return &PathError{path, err1};
+ }
+ if !dir.IsDirectory() {
+ // Not a directory; return the error from Remove.
+ return &PathError{path, err};
+ }
+
+ // Directory.
+ fd, err := Open(path, os.O_RDONLY, 0);
+ if err != nil {
+ return &PathError{path, err};
+ }
+ defer fd.Close();
+
+ // Remove contents & return first error.
+ err = nil;
+ for {
+ names, err1 := fd.Readdirnames(100);
+ for i, name := range names {
+ err1 := RemoveAll(path + "/" + name);
+ if err1 != nil && err == nil {
+ err = err1;
+ }
+ }
+ // If Readdirnames returned an error, use it.
+ if err1 != nil && err == nil {
+ err = &PathError{path, err1};
+ }
+ if len(names) == 0 {
+ break;
+ }
+ }
+
+ // Remove directory.
+ err1 = Remove(path);
+ if err1 != nil && err == nil {
+ err = &PathError{path, err1};
+ }
+ return err;
+}
