code review 4149046: os: Plan 9 support.

src/pkg/os/stat_plan9.go

+// Copyright 2011 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 "syscall"
+
+func fileInfoFromStat(fi *FileInfo, d *Dir) *FileInfo {
+        fi.Dev = uint64(d.Qid.Vers) | uint64(d.Qid.Type<<32)
+        fi.Ino = d.Qid.Path
+
+        fi.Mode = uint32(d.Mode) & 0777
+        if (d.Mode & syscall.DMDIR) == syscall.DMDIR {
+                fi.Mode |= syscall.S_IFDIR
+        } else {
+                fi.Mode |= syscall.S_IFREG
+        }
+
+        fi.Size = int64(d.Length)
+        fi.Atime_ns = 1e9 * int64(d.Atime)
+        fi.Mtime_ns = 1e9 * int64(d.Mtime)
+        fi.Name = d.Name
+        fi.FollowedSymlink = false
+        return fi
+}
+
+// arg is an open *File or a path string.·
+func dirstat(arg interface{}) (fi *FileInfo, err Error) {
+        var name string
+        nd := syscall.STATFIXLEN + 16*4
+
+        for i := 0; i < 2; i++ { /* should work by the second try */
+                buf := make([]byte, nd)
+
+                var n int
+                var e syscall.Error
+
+                switch syscall_arg := arg.(type) {
+                case *File:
+                        name = syscall_arg.name
+                        n, e = syscall.Fstat(syscall_arg.fd, buf)
+                case string:
+                        name = syscall_arg
+                        n, e = syscall.Stat(name, buf)
+                }
+
+                if e != nil {
+                        return nil, &PathError{"stat", name, e}
+                }
+
+                if n < syscall.STATFIXLEN {
+                        return nil, &PathError{"stat", name, Eshortstat}
+                }
+
+                ntmp, _ := gbit16(buf)
+                nd = int(ntmp)
+
+                if nd <= n {
+                        d, e := UnmarshalDir(buf[:n])
+
+                        if e != nil {
+                                return nil, &PathError{"stat", name, e}
+                        }
+
+                        return fileInfoFromStat(new(FileInfo), d), nil
+                }
+        }
+
+        return nil, &PathError{"stat", name, Ebadstat}
+}
+
+
+// Stat returns a FileInfo structure describing the named file and an error, if any.
+func Stat(name string) (fi *FileInfo, err Error) {
+        return dirstat(name)
+}
+
+func Lstat(name string) (fi *FileInfo, err Error) {

[r, 2011/03/31 22:57:46]

copy the comment for Lstat from file.go

[paulzhol, 2011/04/01 20:16:44]

Done.

+        return dirstat(name)
+}