glibc/sysdeps/unix/sysv/linux/getpt.c

102 lines
2.6 KiB
C

/* Copyright (C) 1998-2017 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, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <paths.h>
#include <sys/statfs.h>
#include "linux_fsinfo.h"
/* 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"
/* Prototype for function that opens BSD-style master pseudo-terminals. */
int __bsd_getpt (void);
/* Open a master pseudo terminal and return its file descriptor. */
int
__posix_openpt (int oflag)
{
static int have_no_dev_ptmx;
int fd;
if (!have_no_dev_ptmx)
{
fd = __open (_PATH_DEVPTMX, oflag);
if (fd != -1)
{
struct statfs fsbuf;
static int devpts_mounted;
/* Check that the /dev/pts filesystem is mounted
or if /dev is a devfs filesystem (this implies /dev/pts). */
if (devpts_mounted
|| (__statfs (_PATH_DEVPTS, &fsbuf) == 0
&& fsbuf.f_type == DEVPTS_SUPER_MAGIC)
|| (__statfs (_PATH_DEV, &fsbuf) == 0
&& fsbuf.f_type == DEVFS_SUPER_MAGIC))
{
/* Everything is ok. */
devpts_mounted = 1;
return fd;
}
/* If /dev/pts is not mounted then the UNIX98 pseudo terminals
are not usable. */
__close (fd);
have_no_dev_ptmx = 1;
__set_errno (ENOENT);
}
else
{
if (errno == ENOENT || errno == ENODEV)
have_no_dev_ptmx = 1;
else
return -1;
}
}
else
__set_errno (ENOENT);
return -1;
}
weak_alias (__posix_openpt, posix_openpt)
int
__getpt (void)
{
int fd = __posix_openpt (O_RDWR);
if (fd == -1)
fd = __bsd_getpt ();
return fd;
}
#define PTYNAME1 "pqrstuvwxyzabcde";
#define PTYNAME2 "0123456789abcdef";
#define __getpt __bsd_getpt
#define HAVE_POSIX_OPENPT
#include <sysdeps/unix/bsd/getpt.c>