fflush.c

Go to the documentation of this file.

/*
 * fflush.c - flush stream(s)
 */
/* $Header: /opt/proj/minix/cvsroot/src/lib/stdio/fflush.c,v 1.3 2006/02/02 16:59:07 beng Exp $ */

#include        <sys/types.h>
#include        <stdio.h>
#include        <errno.h>
#include        "loc_incl.h"

ssize_t _write(int d, const char *buf, size_t nbytes);
off_t _lseek(int fildes, off_t offset, int whence);

int
fflush(FILE *stream)
{
        int count, c1, i, retval = 0;

        if (!stream) {
            for(i= 0; i < FOPEN_MAX; i++)
                if (__iotab[i] && fflush(__iotab[i]))
                        retval = EOF;
            return retval;
        }

        if (!stream->_buf
            || (!io_testflag(stream, _IOREADING)
                && !io_testflag(stream, _IOWRITING)))
                return 0;
        if (io_testflag(stream, _IOREADING)) {
                /* (void) fseek(stream, 0L, SEEK_CUR); */
                int adjust = 0;
                if (io_testflag(stream, _IOFIFO)) {
                        /* Can't seek in a pipe. */
                        return 0;
                }
                if (stream->_buf && !io_testflag(stream,_IONBF))
                        adjust = -stream->_count;
                stream->_count = 0;
                if (_lseek(fileno(stream), (off_t) adjust, SEEK_CUR) == -1 &&
                  errno != ESPIPE) {
                        stream->_flags |= _IOERR;
                        return EOF;
                }
                errno = 0;
                if (io_testflag(stream, _IOWRITE))
                        stream->_flags &= ~(_IOREADING | _IOWRITING);
                stream->_ptr = stream->_buf;
                return 0;
        } else if (io_testflag(stream, _IONBF)) return 0;

        if (io_testflag(stream, _IOREAD))               /* "a" or "+" mode */
                stream->_flags &= ~_IOWRITING;

        count = stream->_ptr - stream->_buf;
        stream->_ptr = stream->_buf;

        if ( count <= 0 )
                return 0;

        if (io_testflag(stream, _IOAPPEND)) {
                if (_lseek(fileno(stream), 0L, SEEK_END) == -1) {
                        stream->_flags |= _IOERR;
                        return EOF;
                }
        }
        c1 = _write(stream->_fd, (char *)stream->_buf, count);

        stream->_count = 0;

        if ( count == c1 )
                return 0;

        stream->_flags |= _IOERR;
        return EOF; 
}

void
__cleanup(void)
{
        register int i;

        for(i= 0; i < FOPEN_MAX; i++)
                if (__iotab[i] && io_testflag(__iotab[i], _IOWRITING))
                        (void) fflush(__iotab[i]);
}

---