ack/lang/cem/libcc.ansi/stdio/ftell.c

32 lines
588 B
C

/*
* ftell.c - obtain the value of the file-position indicator of a stream
*/
/* $Id$ */
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include "loc_incl.h"
long ftell(FILE *stream)
{
long result;
int adjust = 0;
if (io_testflag(stream,_IOREADING))
adjust = -stream->_count;
else if (io_testflag(stream,_IOWRITING)
&& stream->_buf
&& !io_testflag(stream,_IONBF))
adjust = stream->_ptr - stream->_buf;
else adjust = 0;
result = lseek(fileno(stream), 0, SEEK_CUR);
if ( result == -1 )
return result;
result += (long) adjust;
return result;
}