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 |
33 | const char __libc_ptyname1[] attribute_hidden = PTYNAME1; |
34 | |
35 | /* Letters indicating the position within a series. */ |
36 | #ifndef PTYNAME2 |
37 | #define PTYNAME2 "0123456789abcdefghijklmnopqrstuv"; |
38 | #endif |
39 | const char __libc_ptyname2[] attribute_hidden = PTYNAME2; |
40 | |
41 | |
42 | /* Open a master pseudo terminal and return its file descriptor. */ |
43 | int |
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 |
78 | weak_alias (__getpt, getpt) |
79 | |
80 | #ifndef HAVE_POSIX_OPENPT |
81 | /* We cannot define posix_openpt in general for BSD systems. */ |
82 | int |
83 | __posix_openpt (int oflag) |
84 | { |
85 | __set_errno (ENOSYS); |
86 | return -1; |
87 | } |
88 | weak_alias (__posix_openpt, posix_openpt) |
89 | |
90 | stub_warning (posix_openpt) |
91 | #endif |
92 | |