func lookupUnixUid(uid int) (*User, error) {
var pwd syscall.Passwd
var result *syscall.Passwd
buf := alloc(userBuffer)
defer buf.free()
err := retryWithBuffer(buf, func() syscall.Errno {
syscall.Entersyscall()
rv := libc_getpwuid_r(syscall.Uid_t(uid),
&pwd,
buf.ptr,
buf.size,
&result)
syscall.Exitsyscall()
if rv != 0 {
return syscall.GetErrno()
}
return 0
})
if err != nil {
return nil, fmt.Errorf("user: lookup userid %d: %v", uid, err)
}
if result == nil {
return nil, UnknownUserIdError(uid)
}
return buildUser(&pwd), nil
}
func lookupUnix(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 {
nameC := syscall.StringBytePtr(username)
syscall.Entersyscall()
rv := libc_getpwnam_r(nameC,
&pwd,
&buf[0],
bufSize,
&result)
syscall.Exitsyscall()
if rv != 0 {
return nil, fmt.Errorf("user: lookup username %s: %s", username, syscall.GetErrno())
}
if result == nil {
return nil, UnknownUserError(username)
}
} else {
syscall.Entersyscall()
rv := libc_getpwuid_r(syscall.Uid_t(uid),
&pwd,
&buf[0],
bufSize,
&result)
syscall.Exitsyscall()
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
}