github.com/zxy12/golang_with_comment@v0.0.0-20190701084843-0e6b2aff5ef3/os/user/lookup_stubs.go (about)

     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  // +build !cgo,!windows,!plan9 android
     6  
     7  package user
     8  
     9  import (
    10  	"errors"
    11  	"fmt"
    12  	"os"
    13  	"runtime"
    14  	"strconv"
    15  )
    16  
    17  func init() {
    18  	groupImplemented = false
    19  }
    20  
    21  func current() (*User, error) {
    22  	u := &User{
    23  		Uid:      currentUID(),
    24  		Gid:      currentGID(),
    25  		Username: os.Getenv("USER"),
    26  		Name:     "", // ignored
    27  		HomeDir:  os.Getenv("HOME"),
    28  	}
    29  	// On NaCL and Android, return a dummy user instead of failing.
    30  	switch runtime.GOOS {
    31  	case "nacl":
    32  		if u.Uid == "" {
    33  			u.Uid = "1"
    34  		}
    35  		if u.Username == "" {
    36  			u.Username = "nacl"
    37  		}
    38  		if u.HomeDir == "" {
    39  			u.HomeDir = "/"
    40  		}
    41  	case "android":
    42  		if u.Uid == "" {
    43  			u.Uid = "1"
    44  		}
    45  		if u.Username == "" {
    46  			u.Username = "android"
    47  		}
    48  		if u.HomeDir == "" {
    49  			u.HomeDir = "/sdcard"
    50  		}
    51  	}
    52  	// cgo isn't available, but if we found the minimum information
    53  	// without it, use it:
    54  	if u.Uid != "" && u.Username != "" && u.HomeDir != "" {
    55  		return u, nil
    56  	}
    57  	return u, fmt.Errorf("user: Current not implemented on %s/%s", runtime.GOOS, runtime.GOARCH)
    58  }
    59  
    60  func listGroups(*User) ([]string, error) {
    61  	if runtime.GOOS == "android" {
    62  		return nil, errors.New("user: GroupIds not implemented on Android")
    63  	}
    64  	return nil, errors.New("user: GroupIds requires cgo")
    65  }
    66  
    67  func currentUID() string {
    68  	if id := os.Getuid(); id >= 0 {
    69  		return strconv.Itoa(id)
    70  	}
    71  	// Note: Windows returns -1, but this file isn't used on
    72  	// Windows anyway, so this empty return path shouldn't be
    73  	// used.
    74  	return ""
    75  }
    76  
    77  func currentGID() string {
    78  	if id := os.Getgid(); id >= 0 {
    79  		return strconv.Itoa(id)
    80  	}
    81  	return ""
    82  }