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 #include <stdlib.h>
38 #include <fcntl.h>
39 #include <unistd.h>
40
41 FILE *
freopen(const char * pathname,const char * mode,FILE * stream)42 freopen(const char *pathname, const char *mode, FILE *stream)
43 {
44 struct __file_bufio *pf = (struct __file_bufio *) stream;
45 int fd;
46 int stdio_flags;
47 int open_flags;
48
49 /* Can't reopen FILEs which aren't buffered */
50 if (!(stream->flags & __SBUF))
51 return NULL;
52
53 stdio_flags = __posix_sflags(mode, &open_flags);
54 if (stdio_flags == 0)
55 return NULL;
56
57 fd = open(pathname, open_flags, 0666);
58 if (fd < 0)
59 return NULL;
60
61 fflush(stream);
62
63 __bufio_lock(stream);
64 close(pf->fd);
65 stream->flags = (stream->flags & ~(__SRD|__SWR|__SERR|__SEOF)) | stdio_flags;
66 pf->pos = 0;
67 pf->fd = fd;
68
69 /* Switch to POSIX backend */
70 pf->read = read;
71 pf->write = write;
72 pf->lseek = lseek;
73 pf->close = close;
74
75 __bufio_unlock(stream);
76
77 return stream;
78 }
79
