statx: make include conditional, fixes non-csky arch buildroot builds
[uclibc-ng.git] / libutil / openpty.c
blob848dc8d380ea7ec984989e62689c73cbd02e0b98
1 /* Copyright (C) 1998, 1999, 2004 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.
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.
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.
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/>. */
19 #include <errno.h>
20 #include <fcntl.h>
21 #include <limits.h>
22 #include <pty.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <termios.h>
26 #include <unistd.h>
27 #include <sys/types.h>
29 /* BCS: the following function is, IMO, overkill */
30 #if 0
31 /* Return the result of ptsname_r in the buffer pointed to by PTS,
32 which should be of length BUF_LEN. If it is too long to fit in
33 this buffer, a sufficiently long buffer is allocated using malloc,
34 and returned in PTS. 0 is returned upon success, -1 otherwise. */
35 static int
36 pts_name (int fd, char **pts, size_t buf_len)
38 int rv;
39 char *buf = *pts;
41 for (;;)
43 char *new_buf;
45 if (buf_len)
47 rv = ptsname_r (fd, buf, buf_len);
49 if (rv != 0 || memchr (buf, '\0', buf_len))
50 /* We either got an error, or we succeeded and the
51 returned name fit in the buffer. */
52 break;
54 /* Try again with a longer buffer. */
55 buf_len += buf_len; /* Double it */
57 else
58 /* No initial buffer; start out by mallocing one. */
59 buf_len = 128; /* First time guess. */
61 if (buf != *pts)
62 /* We've already malloced another buffer at least once. */
63 new_buf = realloc (buf, buf_len);
64 else
65 new_buf = malloc (buf_len);
66 if (! new_buf)
68 rv = -1;
69 __set_errno (ENOMEM);
70 break;
72 buf = new_buf;
75 if (rv == 0)
76 *pts = buf; /* Return buffer to the user. */
77 else if (buf != *pts)
78 free (buf); /* Free what we malloced when returning an error. */
80 return rv;
82 #endif
84 /* Create pseudo tty master slave pair and set terminal attributes
85 according to TERMP and WINP. Return handles for both ends in
86 AMASTER and ASLAVE, and return the name of the slave end in NAME. */
87 int
88 openpty (int *amaster, int *aslave, char *name, struct termios *termp,
89 struct winsize *winp)
91 #if 0
92 #ifdef PATH_MAX
93 char _buf[PATH_MAX];
94 #else
95 char _buf[512];
96 #endif
97 char *buf = _buf;
98 #else
99 #ifdef PATH_MAX
100 char buf[PATH_MAX];
101 #else
102 char buf[512];
103 #endif
104 #endif
105 int master, slave;
107 master = posix_openpt (O_RDWR);
108 if (master == -1)
109 return -1;
111 if (grantpt (master))
112 goto fail;
114 if (unlockpt (master))
115 goto fail;
117 #if 0
118 if (pts_name (master, &buf, sizeof (_buf)))
119 #else
120 if (ptsname_r (master, buf, sizeof buf))
121 #endif
122 goto fail;
124 slave = open (buf, O_RDWR | O_NOCTTY);
125 if (slave == -1)
127 #if 0
128 if (buf != _buf)
129 free (buf);
130 #endif
131 goto fail;
134 /* XXX Should we ignore errors here? */
135 if(termp)
136 tcsetattr (slave, TCSAFLUSH, termp);
137 if (winp)
138 ioctl (slave, TIOCSWINSZ, winp);
140 *amaster = master;
141 *aslave = slave;
142 if (name != NULL)
143 strcpy (name, buf);
145 #if 0
146 if (buf != _buf)
147 free (buf);
148 #endif
149 return 0;
151 fail:
152 close (master);
153 return -1;
155 libutil_hidden_def(openpty)