1 /*
2 * Copyright (c) 1990 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms are permitted
6 * provided that the above copyright notice and this paragraph are
7 * duplicated in all such forms and that any documentation,
8 * and/or other materials related to such
9 * distribution and use acknowledge that the software was developed
10 * by the University of California, Berkeley. The name of the
11 * University may not be used to endorse or promote products derived
12 * from this software without specific prior written permission.
13 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16 */
17
18 /*
19 FUNCTION
20 <<fgetpos>>---record position in a stream or file
21
22 INDEX
23 fgetpos
24 INDEX
25 _fgetpos_r
26
27 SYNOPSIS
28 #include <stdio.h>
29 int fgetpos(FILE *restrict <[fp]>, fpos_t *restrict <[pos]>);
30 int fgetpos( FILE *restrict <[fp]>, fpos_t *restrict <[pos]>);
31
32 DESCRIPTION
33 Objects of type <<FILE>> can have a ``position'' that records how much
34 of the file your program has already read. Many of the <<stdio>> functions
35 depend on this position, and many change it as a side effect.
36
37 You can use <<fgetpos>> to report on the current position for a file
38 identified by <[fp]>; <<fgetpos>> will write a value
39 representing that position at <<*<[pos]>>>. Later, you can
40 use this value with <<fsetpos>> to return the file to this
41 position.
42
43 In the current implementation, <<fgetpos>> simply uses a character
44 count to represent the file position; this is the same number that
45 would be returned by <<ftell>>.
46
47 RETURNS
48 <<fgetpos>> returns <<0>> when successful. If <<fgetpos>> fails, the
49 result is <<1>>. Failure occurs on streams that do not support
50 positioning; the global <<errno>> indicates this condition with the
51 value <<ESPIPE>>.
52
53 PORTABILITY
54 <<fgetpos>> is required by the ANSI C standard, but the meaning of the
55 value it records is not specified beyond requiring that it be
56 acceptable as an argument to <<fsetpos>>. In particular, other
57 conforming C implementations may return a different result from
58 <<ftell>> than what <<fgetpos>> writes at <<*<[pos]>>>.
59
60 No supporting OS subroutines are required.
61 */
62
63 #define _DEFAULT_SOURCE
64 #include <_ansi.h>
65 #include <stdio.h>
66
67 int
fgetpos(FILE * __restrict fp,_fpos_t * __restrict pos)68 fgetpos (
69 FILE *__restrict fp,
70 _fpos_t *__restrict pos)
71 {
72 *pos = ftell ( fp);
73
74 if (*pos != -1)
75 {
76 return 0;
77 }
78 return 1;
79 }
80
