1/* Copyright (C) 1998-2016 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Zack Weinberg <zack@rabi.phys.columbia.edu>, 1998.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
18
19#include <errno.h>
20#include <fcntl.h>
21#include <string.h>
22#include <unistd.h>
23
24
25/* Prefix for master pseudo terminal nodes. */
26#define _PATH_PTY "/dev/pty"
27
28
29/* Letters indicating a series of pseudo terminals. */
30#ifndef PTYNAME1
31#define PTYNAME1 "pqrsPQRS"
32#endif
33const char __libc_ptyname1[] attribute_hidden = PTYNAME1;
34
35/* Letters indicating the position within a series. */
36#ifndef PTYNAME2
37#define PTYNAME2 "0123456789abcdefghijklmnopqrstuv";
38#endif
39const char __libc_ptyname2[] attribute_hidden = PTYNAME2;
40
41
42/* Open a master pseudo terminal and return its file descriptor. */
43int
44__getpt (void)
45{
46 char buf[sizeof (_PATH_PTY) + 2];
47 const char *p, *q;
48 char *s;
49
50 s = __mempcpy (buf, _PATH_PTY, sizeof (_PATH_PTY) - 1);
51 /* s[0] and s[1] will be filled in the loop. */
52 s[2] = '\0';
53
54 for (p = __libc_ptyname1; *p != '\0'; ++p)
55 {
56 s[0] = *p;
57
58 for (q = __libc_ptyname2; *q != '\0'; ++q)
59 {
60 int fd;
61
62 s[1] = *q;
63
64 fd = __open (buf, O_RDWR);
65 if (fd != -1)
66 return fd;
67
68 if (errno == ENOENT)
69 return -1;
70 }
71 }
72
73 __set_errno (ENOENT);
74 return -1;
75}
76
77#undef __getpt
78weak_alias (__getpt, getpt)
79
80#ifndef HAVE_POSIX_OPENPT
81/* We cannot define posix_openpt in general for BSD systems. */
82int
83__posix_openpt (int oflag)
84{
85 __set_errno (ENOSYS);
86 return -1;
87}
88weak_alias (__posix_openpt, posix_openpt)
89
90stub_warning (posix_openpt)
91#endif
92