ack/lang/cem/libcc.ansi/sys/stdio/ftell.c
2018-06-23 18:54:40 +02:00

37 lines
620 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"
#if ACKCONF_WANT_STDIO
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;
}
#endif