1// Copyright 2011 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5//go:build (!cgo && !windows && !plan9) || android || (osusergo && !windows && !plan9)
6
7package user
8
9import (
10	"fmt"
11	"os"
12	"runtime"
13	"strconv"
14)
15
16func current() (*User, error) {
17	uid := currentUID()
18	// $USER and /etc/passwd may disagree; prefer the latter if we can get it.
19	// See issue 27524 for more information.
20	u, err := lookupUserId(uid)
21	if err == nil {
22		return u, nil
23	}
24
25	homeDir, _ := os.UserHomeDir()
26	u = &User{
27		Uid:      uid,
28		Gid:      currentGID(),
29		Username: os.Getenv("USER"),
30		Name:     "", // ignored
31		HomeDir:  homeDir,
32	}
33	// On Android, return a dummy user instead of failing.
34	switch runtime.GOOS {
35	case "android":
36		if u.Uid == "" {
37			u.Uid = "1"
38		}
39		if u.Username == "" {
40			u.Username = "android"
41		}
42	}
43	// cgo isn't available, but if we found the minimum information
44	// without it, use it:
45	if u.Uid != "" && u.Username != "" && u.HomeDir != "" {
46		return u, nil
47	}
48	var missing string
49	if u.Username == "" {
50		missing = "$USER"
51	}
52	if u.HomeDir == "" {
53		if missing != "" {
54			missing += ", "
55		}
56		missing += "$HOME"
57	}
58	return u, fmt.Errorf("user: Current requires cgo or %s set in environment", missing)
59}
60
61func currentUID() string {
62	if id := os.Getuid(); id >= 0 {
63		return strconv.Itoa(id)
64	}
65	// Note: Windows returns -1, but this file isn't used on
66	// Windows anyway, so this empty return path shouldn't be
67	// used.
68	return ""
69}
70
71func currentGID() string {
72	if id := os.Getgid(); id >= 0 {
73		return strconv.Itoa(id)
74	}
75	return ""
76}
77