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
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
|
/* $OpenBSD: fmemopen.c,v 1.2 2013/03/27 15:06:25 mpi Exp $ */
/*
* Copyright (c) 2011 Martin Pieuchot <mpi@openbsd.org>
* Copyright (c) 2009 Ted Unangst
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/* externs from from "local.h" */
FILE *__sfp(void);
int __sflags(const char *, int *);
struct state {
char *string; /* actual stream */
size_t pos; /* current position */
size_t size; /* allocated size */
size_t len; /* length of the data */
int update; /* open for update */
};
static int
fmemopen_read(void *v, char *b, int l)
{
struct state *st = v;
int i;
for (i = 0; i < l && i + st->pos < st->len; i++)
b[i] = st->string[st->pos + i];
st->pos += i;
return (i);
}
static int
fmemopen_write(void *v, const char *b, int l)
{
struct state *st = v;
int i;
for (i = 0; i < l && i + st->pos < st->size; i++)
st->string[st->pos + i] = b[i];
st->pos += i;
if (st->pos >= st->len) {
st->len = st->pos;
if (st->len < st->size)
st->string[st->len] = '\0';
else if (!st->update)
st->string[st->size - 1] = '\0';
}
return (i);
}
static fpos_t
fmemopen_seek(void *v, fpos_t off, int whence)
{
struct state *st = v;
ssize_t base = 0;
switch (whence) {
case SEEK_SET:
break;
case SEEK_CUR:
base = st->pos;
break;
case SEEK_END:
base = st->len;
break;
}
if (off > st->size - base || off < -base) {
errno = EOVERFLOW;
return (-1);
}
st->pos = base + off;
return (st->pos);
}
static int
fmemopen_close(void *v)
{
free(v);
return (0);
}
static int
fmemopen_close_free(void *v)
{
struct state *st = v;
free(st->string);
free(st);
return (0);
}
FILE *
fmemopen(void *buf, size_t size, const char *mode)
{
struct state *st;
FILE *fp;
int flags, oflags;
if (size == 0) {
errno = EINVAL;
return (NULL);
}
if ((flags = __sflags(mode, &oflags)) == 0) {
errno = EINVAL;
return (NULL);
}
if (buf == NULL && ((oflags & O_RDWR) == 0)) {
errno = EINVAL;
return (NULL);
}
if ((st = malloc(sizeof(*st))) == NULL)
return (NULL);
if ((fp = __sfp()) == NULL) {
free(st);
return (NULL);
}
st->pos = 0;
st->len = (oflags & O_WRONLY) ? 0 : size;
st->size = size;
st->update = oflags & O_RDWR;
if (buf == NULL) {
if ((st->string = malloc(size)) == NULL) {
free(st);
fp->_flags = 0;
return (NULL);
}
*st->string = '\0';
} else {
st->string = (char *)buf;
if (oflags & O_TRUNC)
*st->string = '\0';
if (oflags & O_APPEND) {
char *p;
if ((p = memchr(st->string, '\0', size)) != NULL)
st->pos = st->len = (p - st->string);
else
st->pos = st->len = size;
}
}
fp->_flags = (short)flags;
fp->_file = -1;
fp->_cookie = (void *)st;
fp->_read = (flags & __SWR) ? NULL : fmemopen_read;
fp->_write = (flags & __SRD) ? NULL : fmemopen_write;
fp->_seek = fmemopen_seek;
fp->_close = (buf == NULL) ? fmemopen_close_free : fmemopen_close;
return (fp);
}
|
