Subversion Repositories openrisc

// 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.

// +build darwin freebsd linux

// +build cgo

package user

import (

        "fmt"

        "strconv"

        "strings"

        "syscall"

        "unsafe"

)

/*

#include 

#include 

#include 

#include 

static int mygetpwuid_r(int uid, struct passwd *pwd,

        char *buf, size_t buflen, struct passwd **result) {

 return getpwuid_r(uid, pwd, buf, buflen, result);

}

*/

//extern getpwnam_r

func libc_getpwnam_r(name *byte, pwd *syscall.Passwd, buf *byte, buflen syscall.Size_t, result **syscall.Passwd) int

//extern getpwuid_r

func libc_getpwuid_r(uid syscall.Uid_t, pwd *syscall.Passwd, buf *byte, buflen syscall.Size_t, result **syscall.Passwd) int

// bytePtrToString takes a NUL-terminated array of bytes and convert

// it to a Go string.

func bytePtrToString(p *byte) string {

        a := (*[10000]byte)(unsafe.Pointer(p))

        i := 0

        for a[i] != 0 {

                i++

        }

        return string(a[:i])

}

// Current returns the current user.

func Current() (*User, error) {

        return lookup(syscall.Getuid(), "", false)

}

// Lookup looks up a user by username. If the user cannot be found,

// the returned error is of type UnknownUserError.

func Lookup(username string) (*User, error) {

        return lookup(-1, username, true)

}

// LookupId looks up a user by userid. If the user cannot be found,

// the returned error is of type UnknownUserIdError.

func LookupId(uid string) (*User, error) {

        i, e := strconv.Atoi(uid)

        if e != nil {

                return nil, e

        }

        return lookup(i, "", false)

}

func lookup(uid int, username string, lookupByName bool) (*User, error) {

        var pwd syscall.Passwd

        var result *syscall.Passwd

        // FIXME: Should let buf grow if necessary.

        const bufSize = 1024

        buf := make([]byte, bufSize)

        if lookupByName {

                rv := libc_getpwnam_r(syscall.StringBytePtr(username),

                        &pwd,

                        &buf[0],

                        bufSize,

                        &result)

                if rv != 0 {

                        return nil, fmt.Errorf("user: lookup username %s: %s", username, syscall.GetErrno())

                }

                if result == nil {

                        return nil, UnknownUserError(username)

                }

        } else {

                rv := libc_getpwuid_r(syscall.Uid_t(uid),

                        &pwd,

                        &buf[0],

                        bufSize,

                        &result)

                if rv != 0 {

                        return nil, fmt.Errorf("user: lookup userid %d: %s", uid, syscall.GetErrno())

                }

                if result == nil {

                        return nil, UnknownUserIdError(uid)

                }

        }

        u := &User{

                Uid:      strconv.Itoa(int(pwd.Pw_uid)),

                Gid:      strconv.Itoa(int(pwd.Pw_gid)),

                Username: bytePtrToString((*byte)(unsafe.Pointer(pwd.Pw_name))),

                Name:     bytePtrToString((*byte)(unsafe.Pointer(pwd.Pw_gecos))),

                HomeDir:  bytePtrToString((*byte)(unsafe.Pointer(pwd.Pw_dir))),

        }

        // The pw_gecos field isn't quite standardized.  Some docs

        // say: "It is expected to be a comma separated list of

        // personal data where the first item is the full name of the

        // user."

        if i := strings.Index(u.Name, ","); i >= 0 {

                u.Name = u.Name[:i]

        }

        return u, nil

}