blob: 7d942a1c25c7c3fa207daf3b4faf15b1d7e90a2f (
plain)
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
|
/*
* fseeko.c
* 64-bit versions of fseeko/ftello() for systems which do not have them
*/
#include "config.h"
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#ifdef WIN32
#define flockfile
#define funlockfile
#endif
/*
* On BSD/OS and NetBSD (and perhaps others), off_t and fpos_t are the
* same. Standards say off_t is an arithmetic type, but not necessarily
* integral, while fpos_t might be neither.
*
* This is thread-safe on BSD/OS using flockfile/funlockfile.
*/
int
fseeko(FILE *stream, off_t offset, int whence)
{
fpos_t floc;
struct stat filestat;
switch (whence)
{
case SEEK_CUR:
flockfile(stream);
if (fgetpos(stream, &floc) != 0)
goto failure;
floc += offset;
if (fsetpos(stream, &floc) != 0)
goto failure;
funlockfile(stream);
return 0;
break;
case SEEK_SET:
if (fsetpos(stream, &offset) != 0)
return -1;
return 0;
break;
case SEEK_END:
flockfile(stream);
if (fstat(fileno(stream), &filestat) != 0)
goto failure;
floc = filestat.st_size;
if (fsetpos(stream, &floc) != 0)
goto failure;
funlockfile(stream);
return 0;
break;
default:
errno = EINVAL;
return -1;
}
failure:
funlockfile(stream);
return -1;
}
|
