34 lines
612 B
C
34 lines
612 B
C
/*
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* ftell.c - obtain the value of the file-position indicator of a stream
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*/
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/* $Header$ */
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#include <stdio.h>
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#include <sys/file.h>
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#include "loc_incl.h"
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int lseek(int d, int offset, int whence);
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long ftell(FILE * stream)
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{
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long result;
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int adjust;
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if ( io_testflag(stream,_IOREAD) )
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adjust = -stream->_count;
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else if (io_testflag(stream,_IOWRITE)
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&& stream->_buf
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&& !io_testflag(stream,_IONBF))
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adjust = stream->_ptr - stream->_buf;
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else
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return -1L;
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result = lseek(fileno(stream), 0, L_INCR);
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if ( result == -1 )
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return result;
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result += (long) adjust;
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return result;
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}
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