83 lines
2.3 KiB
C
83 lines
2.3 KiB
C
/*
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* Copyright (c) 1990 The Regents of the University of California.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms are permitted
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* provided that the above copyright notice and this paragraph are
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* duplicated in all such forms and that any documentation,
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* and/or other materials related to such
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* distribution and use acknowledge that the software was developed
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* by the University of California, Berkeley. The name of the
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* University may not be used to endorse or promote products derived
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* from this software without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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*/
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/*
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FUNCTION
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<<fsetpos>>---restore position of a stream or file
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INDEX
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fsetpos
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INDEX
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_fsetpos_r
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SYNOPSIS
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#include <stdio.h>
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int fsetpos(FILE *<[fp]>, const fpos_t *<[pos]>);
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int _fsetpos_r(struct _reent *<[ptr]>, FILE *<[fp]>,
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const fpos_t *<[pos]>);
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DESCRIPTION
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Objects of type <<FILE>> can have a ``position'' that records how much
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of the file your program has already read. Many of the <<stdio>> functions
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depend on this position, and many change it as a side effect.
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You can use <<fsetpos>> to return the file identified by <[fp]> to a previous
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position <<*<[pos]>>> (after first recording it with <<fgetpos>>).
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See <<fseek>> for a similar facility.
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RETURNS
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<<fgetpos>> returns <<0>> when successful. If <<fgetpos>> fails, the
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result is <<1>>. The reason for failure is indicated in <<errno>>:
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either <<ESPIPE>> (the stream identified by <[fp]> doesn't support
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repositioning) or <<EINVAL>> (invalid file position).
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PORTABILITY
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ANSI C requires <<fsetpos>>, but does not specify the nature of
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<<*<[pos]>>> beyond identifying it as written by <<fgetpos>>.
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Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
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<<lseek>>, <<read>>, <<sbrk>>, <<write>>.
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*/
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#include <_ansi.h>
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#include <reent.h>
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#include <stdio.h>
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int
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_fsetpos_r (struct _reent * ptr,
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FILE * iop,
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const _fpos_t * pos)
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{
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int x = _fseek_r (ptr, iop, *pos, SEEK_SET);
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if (x != 0)
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return 1;
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return 0;
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}
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#ifndef _REENT_ONLY
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int
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fsetpos (FILE * iop,
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const _fpos_t * pos)
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{
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return _fsetpos_r (_REENT, iop, pos);
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}
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#endif /* !_REENT_ONLY */
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