29 lines
675 B
C
29 lines
675 B
C
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#include <stdio.h>
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#include <sys/locking.h>
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#include <share.h>
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#include <fcntl.h>
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#include <io.h>
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void main()
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{
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int handle;
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unsigned nbytes;
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unsigned long offset;
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auto char buffer[512];
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nbytes = 512;
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offset = 1024;
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handle = sopen( "db.fil", O_RDWR, SH_DENYNO );
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if( handle != -1 ) {
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lseek( handle, offset, SEEK_SET );
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locking( handle, LK_LOCK, nbytes );
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read( handle, buffer, nbytes );
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/* update data in the buffer */
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lseek( handle, offset, SEEK_SET );
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write( handle, buffer, nbytes );
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lseek( handle, offset, SEEK_SET );
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locking( handle, LK_UNLCK, nbytes );
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close( handle );
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}
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}
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