67 lines
1.6 KiB
C
67 lines
1.6 KiB
C
#ifdef __LARGE64_FILES
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/*
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FUNCTION
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<<fgetpos64>>---record position in a large stream or file
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INDEX
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fgetpos64
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ANSI_SYNOPSIS
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#include <stdio.h>
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int fgetpos64(FILE *<[fp]>, _fpos64_t *<[pos]>);
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TRAD_SYNOPSIS
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#include <stdio.h>
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int fgetpos64(<[fp]>, <[pos]>)
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FILE *<[fp]>;
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_fpos64_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 <<fgetpos64>> to report on the current position for a file
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identified by <[fp]> that was opened by <<fopen64>>; <<fgetpos>> will write
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a value representing that position at <<*<[pos]>>>. Later, you can
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use this value with <<fsetpos64>> to return the file to this
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position.
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In the current implementation, <<fgetpos64>> simply uses a character
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count to represent the file position; this is the same number that
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would be returned by <<ftello64>>.
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RETURNS
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<<fgetpos64>> returns <<0>> when successful. If <<fgetpos64>> fails, the
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result is <<1>>. Failure occurs on streams that do not support
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positioning or streams not opened via <<fopen64>>; the global <<errno>>
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indicates these conditions with the value <<ESPIPE>>.
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PORTABILITY
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<<fgetpos64>> is a glibc extension.
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No supporting OS subroutines are required.
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*/
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#include <stdio.h>
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int
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_DEFUN (fgetpos64, (fp, pos),
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FILE * fp _AND
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_fpos64_t * pos)
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{
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_flockfile(fp);
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*pos = (_fpos64_t)ftello64 (fp);
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if (*pos != -1)
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{
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_funlockfile(fp);
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return 0;
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}
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_funlockfile(fp);
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return 1;
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}
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#endif /* __LARGE64_FILES */
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