1  /* Copyright (C) 2016-2023 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
      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
      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  }