1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
|
/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
/*static char *sccsid = "from: @(#)freopen.c 5.6 (Berkeley) 2/24/91";*/
static char *rcsid = "$Id: freopen.c,v 1.1 1995/10/18 08:43:07 deraadt Exp $";
#endif /* LIBC_SCCS and not lint */
#include <pthread.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include "local.h"
extern pthread_mutex_t __sfp_mutex;
extern pthread_cond_t __sfp_cond;
extern int __sfp_state;
/*
* Re-direct an existing, open (probably) file to some other file.
* ANSI is written such that the original file gets closed if at
* all possible, no matter what.
*/
FILE *
freopen(file, mode, fp)
const char *file, *mode;
register FILE *fp;
{
int f, flags, oflags;
FILE *ret;
if ((flags = __sflags(mode, &oflags)) == 0) {
(void) fclose(fp);
return (NULL);
}
pthread_once(&__sdidinit, __sinit);
/*
* There are actually programs that depend on being able to "freopen"
* descriptors that weren't originally open. Keep this from breaking.
* Remember whether the stream was open to begin with, and which file
* descriptor (if any) was associated with it. If it was attached to
* a descriptor, defer closing it; freopen("/dev/stdin", "r", stdin)
* should work. This is unnecessary if it was not a Unix file.
*/
/* while lock __sfp_mutex, to block out fopen, and other freopen calls */
while (pthread_mutex_lock(&__sfp_mutex) == OK) {
if (ftrylockfile(fp) == OK) {
if (fp->_flags) {
/* flush the stream; ANSI doesn't require this. */
if (fp->_flags & __SWR)
(void) __sflush(fp);
__sclose(fp);
/*
* Finish closing fp. We cannot keep fp->_base:
* it may be the wrong size. This loses the effect
* of any setbuffer calls, but stdio has always done
* this before.
* NOTE: We do this even if __ftrylockfilr failed with
* an error to avoid memory leaks.
*/
if (fp->_flags & __SMBF)
free((char *)fp->_bf._base);
fp->_w = 0;
fp->_r = 0;
fp->_p = NULL;
fp->_bf._base = NULL;
fp->_bf._size = 0;
fp->_lbfsize = 0;
if (HASUB(fp))
FREEUB(fp);
fp->_ub._size = 0;
if (HASLB(fp))
FREELB(fp);
fp->_lb._size = 0;
}
/* Get a new descriptor to refer to the new file. */
if ((f = open(file, oflags, 0666)) < OK)
ret = NULL;
/*
* If reopening something that was open before on a real file, try
* to maintain the descriptor. Various C library routines (perror)
* assume stderr is always fd STDERR_FILENO, even if being freopen'd.
*/
/* Testing f == fp->_file may no longer be necessary */
if (fp->_file >= 0 && f != fp->_file) {
if (dup2(f, fp->_file) >= OK) {
(void)close(f);
f = fp->_file;
}
}
fp->_flags = flags;
fp->_file = f;
ret = fp;
break;
} else {
/* unlock __sfp_mutex, and try again later */
pthread_mutex_unlock(&__sfp_mutex);
pthread_yield();
continue;
}
pthread_mutex_unlock(&__sfp_mutex);
funlockfile(fp);
return(ret);
}
(void)fclose(fp);
return(NULL);
}
|
