glibc/sysdeps/unix/bsd/getpt.c

92 lines
2.2 KiB
C

/* Copyright (C) 1998-2015 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 <string.h>
#include <unistd.h>
/* Prefix for master pseudo terminal nodes. */
#define _PATH_PTY "/dev/pty"
/* Letters indicating a series of pseudo terminals. */
#ifndef PTYNAME1
#define PTYNAME1 "pqrsPQRS"
#endif
const char __libc_ptyname1[] attribute_hidden = PTYNAME1;
/* Letters indicating the position within a series. */
#ifndef PTYNAME2
#define PTYNAME2 "0123456789abcdefghijklmnopqrstuv";
#endif
const char __libc_ptyname2[] attribute_hidden = PTYNAME2;
/* Open a master pseudo terminal and return its file descriptor. */
int
__getpt (void)
{
char buf[sizeof (_PATH_PTY) + 2];
const char *p, *q;
char *s;
s = __mempcpy (buf, _PATH_PTY, sizeof (_PATH_PTY) - 1);
/* s[0] and s[1] will be filled in the loop. */
s[2] = '\0';
for (p = __libc_ptyname1; *p != '\0'; ++p)
{
s[0] = *p;
for (q = __libc_ptyname2; *q != '\0'; ++q)
{
int fd;
s[1] = *q;
fd = __open (buf, O_RDWR);
if (fd != -1)
return fd;
if (errno == ENOENT)
return -1;
}
}
__set_errno (ENOENT);
return -1;
}
#undef __getpt
weak_alias (__getpt, getpt)
#ifndef HAVE_POSIX_OPENPT
/* We cannot define posix_openpt in general for BSD systems. */
int
__posix_openpt (int oflag)
{
__set_errno (ENOSYS);
return -1;
}
weak_alias (__posix_openpt, posix_openpt)
stub_warning (posix_openpt)
#endif