/* 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; #if !defined __ASSUME_DEVPTS__ /* 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 ( #if !defined __UNIX98PTY_ONLY__ (_state & devpts_mounted) || #endif (__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. */ #if !defined __UNIX98PTY_ONLY__ _state |= devpts_mounted; #endif 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; } } #if !defined __UNIX98PTY_ONLY__ && defined __UCLIBC_HAS_GETPT__ /* If we have no ptmx then ignore flags and use the fallback. */ if (_state & have_no_dev_ptmx) return __bsd_getpt(); #endif return -1; } libc_hidden_def(posix_openpt) #undef have_no_dev_ptmx #undef devpts_mounted #if defined __USE_GNU && defined __UCLIBC_HAS_GETPT__ int getpt (void) { return posix_openpt(O_RDWR); } #if !defined __UNIX98PTY_ONLY__ && defined __UCLIBC_HAS_GETPT__ # define PTYNAME1 "pqrstuvwxyzabcde"; # define PTYNAME2 "0123456789abcdef"; # define __getpt __bsd_getpt # include "bsd_getpt.c" #endif #endif /* GNU && __UCLIBC_HAS_GETPT__ */