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 <<fsetpos>>---restore position of a stream or file
21
22 INDEX
23 fsetpos
24 INDEX
25 _fsetpos_r
26
27 SYNOPSIS
28 #include <stdio.h>
29 int fsetpos(FILE *<[fp]>, const fpos_t *<[pos]>);
30 int fsetpos( FILE *<[fp]>,
31 const fpos_t *<[pos]>);
32
33 DESCRIPTION
34 Objects of type <<FILE>> can have a ``position'' that records how much
35 of the file your program has already read. Many of the <<stdio>> functions
36 depend on this position, and many change it as a side effect.
37
38 You can use <<fsetpos>> to return the file identified by <[fp]> to a previous
39 position <<*<[pos]>>> (after first recording it with <<fgetpos>>).
40
41 See <<fseek>> for a similar facility.
42
43 RETURNS
44 <<fgetpos>> returns <<0>> when successful. If <<fgetpos>> fails, the
45 result is <<1>>. The reason for failure is indicated in <<errno>>:
46 either <<ESPIPE>> (the stream identified by <[fp]> doesn't support
47 repositioning) or <<EINVAL>> (invalid file position).
48
49 PORTABILITY
50 ANSI C requires <<fsetpos>>, but does not specify the nature of
51 <<*<[pos]>>> beyond identifying it as written by <<fgetpos>>.
52
53 Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
54 <<lseek>>, <<read>>, <<sbrk>>, <<write>>.
55 */
56
57 #define _DEFAULT_SOURCE
58 #include <_ansi.h>
59 #include <stdio.h>
60
61 int
fsetpos(FILE * iop,const _fpos_t * pos)62 fsetpos (
63 FILE * iop,
64 const _fpos_t * pos)
65 {
66 int x = fseek ( iop, *pos, SEEK_SET);
67
68 if (x != 0)
69 return 1;
70 return 0;
71 }
72
