1 | /* Copyright (C) 1998-2022 Free Software Foundation, Inc. |
2 | This file is part of the GNU C Library. |
3 | |
4 | The GNU C Library is free software; you can redistribute it and/or |
5 | modify it under the terms of the GNU Lesser General Public |
6 | License as published by the Free Software Foundation; either |
7 | version 2.1 of the License, or (at your option) any later version. |
8 | |
9 | The GNU C Library is distributed in the hope that it will be useful, |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
12 | Lesser General Public License for more details. |
13 | |
14 | You should have received a copy of the GNU Lesser General Public |
15 | License along with the GNU C Library; if not, see |
16 | <https://www.gnu.org/licenses/>. */ |
17 | |
18 | #include <errno.h> |
19 | #include <fcntl.h> |
20 | #include <string.h> |
21 | #include <unistd.h> |
22 | #include <stdlib.h> |
23 | |
24 | /* Prefix for master pseudo terminal nodes. */ |
25 | #define _PATH_PTY "/dev/pty" |
26 | |
27 | |
28 | /* Letters indicating a series of pseudo terminals. */ |
29 | #ifndef PTYNAME1 |
30 | #define PTYNAME1 "pqrsPQRS" |
31 | #endif |
32 | const char __libc_ptyname1[] attribute_hidden = PTYNAME1; |
33 | |
34 | /* Letters indicating the position within a series. */ |
35 | #ifndef PTYNAME2 |
36 | #define PTYNAME2 "0123456789abcdefghijklmnopqrstuv"; |
37 | #endif |
38 | const char __libc_ptyname2[] attribute_hidden = PTYNAME2; |
39 | |
40 | |
41 | /* Open a master pseudo terminal and return its file descriptor. */ |
42 | int |
43 | __bsd_openpt (int oflag) |
44 | { |
45 | char buf[sizeof (_PATH_PTY) + 2]; |
46 | const char *p, *q; |
47 | char *s; |
48 | |
49 | s = __mempcpy (buf, _PATH_PTY, sizeof (_PATH_PTY) - 1); |
50 | /* s[0] and s[1] will be filled in the loop. */ |
51 | s[2] = '\0'; |
52 | |
53 | for (p = __libc_ptyname1; *p != '\0'; ++p) |
54 | { |
55 | s[0] = *p; |
56 | |
57 | for (q = __libc_ptyname2; *q != '\0'; ++q) |
58 | { |
59 | int fd; |
60 | |
61 | s[1] = *q; |
62 | |
63 | fd = __open (buf, oflag); |
64 | if (fd != -1) |
65 | return fd; |
66 | |
67 | if (errno == ENOENT) |
68 | return -1; |
69 | } |
70 | } |
71 | |
72 | __set_errno (ENOENT); |
73 | return -1; |
74 | } |
75 | |
76 | int |
77 | __getpt (void) |
78 | { |
79 | return __bsd_openpt (O_RDWR); |
80 | } |
81 | libc_hidden_def (__getpt) |
82 | weak_alias (__getpt, getpt) |
83 | |
84 | int |
85 | __posix_openpt (int oflag) |
86 | { |
87 | return __bsd_openpt (oflag); |
88 | } |
89 | weak_alias (__posix_openpt, posix_openpt) |
90 | |