1 /* Reentrant function to return the current login name. Unix version.
2 Copyright (C) 1991, 1992, 1996 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Library General Public License as
7 published by the Free Software Foundation; either version 2 of the
8 License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Library General Public License for more details.
15 You should have received a copy of the GNU Library General Public
16 License along with the GNU C Library; see the file COPYING.LIB. If not,
17 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA. */
29 /* Return at most NAME_LEN characters of the login name of the user in NAME.
30 If it cannot be determined or some other error occured, return the error
31 code. Otherwise return 0. */
34 getlogin_r (name
, name_len
)
38 char tty_pathname
[2 + 2 * NAME_MAX
];
39 char *real_tty_path
= tty_pathname
;
41 struct utmp
*ut
, line
, buffer
;
45 int d
= __open ("/dev/tty", 0);
49 result
= ttyname_r (d
, real_tty_path
, sizeof (tty_pathname
));
60 real_tty_path
+= 5; /* Remove "/dev/". */
63 strncpy (line
.ut_line
, real_tty_path
, sizeof line
.ut_line
);
64 if (__getutline_r (&line
, &buffer
, &ut
) < 0)
67 /* The caller expects ENOENT if nothing is found. */
74 size_t needed
= strlen (ut
->ut_line
) + 1;
76 if (needed
< name_len
)
83 memcpy (name
, ut
->ut_line
, needed
);