sysdeps/unix/sysv/linux/ttyname.h

   1 /* Copyright (C) 2016-2019 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 <http://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 *sb)
  29 {
  30 #ifdef _STATBUF_ST_RDEV
  31   int m = __gnu_dev_major (sb->st_rdev);
  32   return (136 <= m && m <= 143);
  33 #else
  34   return false;
  35 #endif
  36 }
  37
  38 static inline bool
  39 is_mytty (const struct stat64 *mytty, const struct stat64 *maybe)
  40 {
  41   return (maybe->st_ino == mytty->st_ino
  42           && maybe->st_dev == mytty->st_dev
  43 #ifdef _STATBUF_ST_RDEV
  44           && S_ISCHR (maybe->st_mode)
  45           && maybe->st_rdev == mytty->st_rdev
  46 #endif
  47           );
  48 }