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
|
#include <__stdio.h>
#include <errno.h> // for EINVAL, errno
#include <fcntl.h> // for O_WRONLY, O_CREAT, O_RDONLY, open, O_APPEND
#include <stdio.h> // for FILE, BUFSIZ, fopen, _IOLBF
#include <stdlib.h> // for calloc, free, malloc
#include <string.h> // for strchr
#include <sys/cdefs.h>
#include <unistd.h> // for close
FILE *fopen(const char *restrict pathname, const char *restrict mode)
{
int fd, flags, _mode;
FILE *stream;
_mode = 0;
if (mode[0] == 'r') {
flags = O_RDONLY;
} else if (mode[0] == 'w') {
flags = O_WRONLY | O_CREAT | O_TRUNC;
} else if (mode[0] == 'a') {
flags = O_WRONLY | O_CREAT | O_APPEND;
_mode = 0666;
} else {
errno = EINVAL;
return NULL;
}
if (strchr(mode, '+')) {
flags = (flags & ~(O_RDONLY | O_WRONLY)) | O_RDWR;
}
fd = open(pathname, flags, _mode);
if (fd < 0)
return NULL;
stream = calloc(1, sizeof(struct __FILE));
if (stream == NULL)
return NULL;
stream->fd = fd;
stream->buf_size = BUFSIZ;
stream->flags = flags;
stream->type = _IOLBF;
atomic_flag_clear(&stream->lock);
stream->buf = malloc(BUFSIZ);
if (stream->buf == NULL) {
close(fd);
free(stream);
return NULL;
}
__libc_fadd(stream);
return stream;
}
|
