1 /*
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright © 2019 Keith Packard
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above
14 * copyright notice, this list of conditions and the following
15 * disclaimer in the documentation and/or other materials provided
16 * with the distribution.
17 *
18 * 3. Neither the name of the copyright holder nor the names of its
19 * contributors may be used to endorse or promote products derived
20 * from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
26 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
27 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
28 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
29 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
31 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
33 * OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35
36 #include "stdio_private.h"
37
38 FILE *
freopen(const char * pathname,const char * mode,FILE * stream)39 freopen(const char *pathname, const char *mode, FILE *stream)
40 {
41 struct __file_bufio *pf = (struct __file_bufio *) stream;
42 int fd;
43 int stdio_flags;
44 int open_flags;
45
46 /* Can't reopen FILEs which aren't buffered */
47 if (!(stream->flags & __SBUF))
48 return NULL;
49
50 stdio_flags = __posix_sflags(mode, &open_flags);
51 if (stdio_flags == 0)
52 return NULL;
53
54 fd = open(pathname, open_flags, 0666);
55 if (fd < 0)
56 return NULL;
57
58 fflush(stream);
59
60 __bufio_lock(stream);
61 close((int)(intptr_t) (pf->ptr));
62 (void) __atomic_exchange_ungetc(&stream->unget, 0);
63 stream->flags = (stream->flags & ~(__SRD|__SWR|__SERR|__SEOF)) | stdio_flags;
64 pf->pos = 0;
65 pf->ptr = (void *) (intptr_t) (fd);
66
67 /* Switch to POSIX backend */
68 pf->read_int = read;
69 pf->write_int = write;
70 pf->lseek_int = lseek;
71 pf->close_int = close;
72
73 __bufio_unlock(stream);
74
75 return stream;
76 }
77
