1 /* Copyright (C) 2016-2022 Free Software Foundation, Inc.
2    This file is part of the GNU C Library.
3 
4    The GNU C Library is free software; you can redistribute it and/or
5    modify it under the terms of the GNU Lesser General Public License as
6    published by the Free Software Foundation; either version 2.1 of the
7    License, or (at your option) any later version.
8 
9    The GNU C Library is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12    Lesser General Public License for more details.
13 
14    You should have received a copy of the GNU Lesser General Public
15    License along with the GNU C Library; see the file COPYING.LIB.  If
16    not, see <https://www.gnu.org/licenses/>.  */
17 
18 #include <unistd.h>
19 #include <stdbool.h>
20 #include <sys/sysmacros.h>
21 #include <sys/types.h>
22 #include <sys/stat.h>
23 
24 /* Return true if this is a UNIX98 pty device, as defined in
25    linux/Documentation/devices.txt (on linux < 4.10) or
26    linux/Documentation/admin-guide/devices.txt (on linux >= 4.10).  */
27 static inline bool
is_pty(struct __stat64_t64 * sb)28 is_pty (struct __stat64_t64 *sb)
29 {
30   int m = __gnu_dev_major (sb->st_rdev);
31   return (136 <= m && m <= 143);
32 }
33 
34 static inline bool
is_mytty(const struct __stat64_t64 * mytty,const struct __stat64_t64 * maybe)35 is_mytty (const struct __stat64_t64 *mytty, const struct __stat64_t64 *maybe)
36 {
37   return (maybe->st_ino == mytty->st_ino
38 	  && maybe->st_dev == mytty->st_dev
39 	  && S_ISCHR (maybe->st_mode)
40 	  && maybe->st_rdev == mytty->st_rdev
41 	  );
42 }
43