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/* Copyright (C) 1998, 1999, 2001 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Zack Weinberg <zack@rabi.phys.columbia.edu>, 1998.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <stdbool.h>
#include <unistd.h>
#include <paths.h>
#include <sys/statfs.h>
extern __typeof(statfs) __libc_statfs;
libc_hidden_proto(__libc_statfs)
libc_hidden_proto(open)
libc_hidden_proto(close)
#if !defined __ASSUME_DEVPTS__
# include <sys/statfs.h>
/* Constant that identifies the `devpts' filesystem. */
# define DEVPTS_SUPER_MAGIC 0x1cd1
/* Constant that identifies the `devfs' filesystem. */
# define DEVFS_SUPER_MAGIC 0x1373
#endif
/* Path to the master pseudo terminal cloning device. */
#define _PATH_DEVPTMX _PATH_DEV "ptmx"
/* Directory containing the UNIX98 pseudo terminals. */
#define _PATH_DEVPTS _PATH_DEV "pts"
#if !defined __UNIX98PTY_ONLY__ && defined __UCLIBC_HAS_GETPT__
/* Prototype for function that opens BSD-style master pseudo-terminals. */
extern int __bsd_getpt (void) attribute_hidden;
#endif
/* Open a master pseudo terminal and return its file descriptor. */
int
posix_openpt (int flags)
{
#define have_no_dev_ptmx (1<<0)
#define devpts_mounted (1<<1)
#if !defined __UNIX98PTY_ONLY__
static smallint _state;
#endif
int fd;
#if !defined __UNIX98PTY_ONLY__
if (!(_state & have_no_dev_ptmx))
#endif
{
fd = open (_PATH_DEVPTMX, flags);
if (fd != -1)
{
#if defined __ASSUME_DEVPTS__
return fd;
#else
struct statfs fsbuf;
/* Check that the /dev/pts filesystem is mounted
or if /dev is a devfs filesystem (this implies /dev/pts). */
if ((_state & devpts_mounted)
|| (__libc_statfs (_PATH_DEVPTS, &fsbuf) == 0
&& fsbuf.f_type == DEVPTS_SUPER_MAGIC)
|| (__libc_statfs (_PATH_DEV, &fsbuf) == 0
&& fsbuf.f_type == DEVFS_SUPER_MAGIC))
{
/* Everything is ok. */
_state |= devpts_mounted;
return fd;
}
/* If /dev/pts is not mounted then the UNIX98 pseudo terminals
are not usable. */
close (fd);
#if !defined __UNIX98PTY_ONLY__
_state |= have_no_dev_ptmx;
#endif
#endif
}
else
{
#if !defined __UNIX98PTY_ONLY__
if (errno == ENOENT || errno == ENODEV)
_state |= have_no_dev_ptmx;
else
#endif
return -1;
}
}
return -1;
}
#undef have_no_dev_ptmx
#undef devpts_mounted
#if defined __USE_GNU && defined __UCLIBC_HAS_GETPT__
int
getpt (void)
{
int fd = posix_openpt(O_RDWR);
#if !defined __UNIX98PTY_ONLY__
if (fd == -1)
fd = __bsd_getpt();
#endif
return fd;
}
#if !defined __UNIX98PTY_ONLY__
# define PTYNAME1 "pqrstuvwxyzabcde";
# define PTYNAME2 "0123456789abcdef";
# define __getpt __bsd_getpt
# include "bsd_getpt.c"
#endif
#endif /* GNU && __UCLIBC_HAS_GETPT__ */
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