50 lines
1.1 KiB
C
50 lines
1.1 KiB
C
/* _PDCLIB_prepread( FILE * )
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This file is part of the Public Domain C Library (PDCLib).
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Permission is granted to use, modify, and / or redistribute at will.
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*/
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#include <stdio.h>
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#include <errno.h>
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#ifndef REGTEST
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#include "_PDCLIB_glue.h"
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int _PDCLIB_prepread( FILE * stream )
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{
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if ( ( stream->bufidx > stream->bufend ) ||
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( stream->status & ( _PDCLIB_FWRITE | _PDCLIB_FAPPEND | _PDCLIB_ERRORFLAG | _PDCLIB_WIDESTREAM | _PDCLIB_EOFFLAG ) ) ||
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! ( stream->status & ( _PDCLIB_FREAD | _PDCLIB_FRW ) ) )
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{
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/* Function called on illegal (e.g. output) stream.
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See comments on implementation-defined errno values in
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<_PDCLIB_config.h>.
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*/
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errno = EINVAL;
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stream->status |= _PDCLIB_ERRORFLAG;
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return EOF;
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}
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stream->status |= _PDCLIB_FREAD | _PDCLIB_BYTESTREAM;
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if ( ( stream->bufidx == stream->bufend ) && ( stream->ungetidx == 0 ) )
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{
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return _PDCLIB_fillbuffer( stream );
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}
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else
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{
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return 0;
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}
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}
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#endif
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#ifdef TEST
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#include "_PDCLIB_test.h"
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int main( void )
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{
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/* Testing covered by ftell.c */
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return TEST_RESULTS;
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}
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#endif
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