77 lines
1.8 KiB
C
77 lines
1.8 KiB
C
/*
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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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ANSI_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]>, l
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const fpos_t *<[pos]>);
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TRAD_SYNOPSIS
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#include <stdio.h>
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int fsetpos(<[fp]>, <[pos]>)
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FILE *<[fp]>;
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fpos_t *<[pos]>;
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int _fsetpos_r(<[ptr]>, <[fp]>, <[pos]>)
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struct _reent *<[ptr]>;
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FILE *<[fp]>;
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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 <stdio.h>
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int
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_DEFUN (_fsetpos_r, (ptr, iop, pos),
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struct _reent * ptr _AND
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FILE * iop _AND
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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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_DEFUN (fsetpos, (iop, pos),
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FILE * iop _AND
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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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