stdio/sys5/filbuf.c

	filbuf.c revision 5d54f3d8999eac1762fe0a8c7177d20f1f201fae
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 1998 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1984 AT&T */
/*        All Rights Reserved   */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*LINTLIBRARY*/
#include <stdio.h>
#include <unistd.h>

extern void _findbuf();

static void lbfflush(FILE *);

int
__filbuf(FILE *iop)
{
    return (_filbuf(iop));
}

int
_filbuf(FILE *iop)
{
    if ( !(iop->_flag & _IOREAD) )
        if (iop->_flag & _IORW)
            iop->_flag |= _IOREAD;
        else
            return(EOF);

    if (iop->_flag&_IOSTRG)
        return(EOF);

    if (iop->_base == NULL)  /* get buffer if we don't have one */
        _findbuf(iop);

    /* if this device is a terminal (line-buffered) or unbuffered, then */
    /* flush buffers of all line-buffered devices currently writing */

    if (iop->_flag & (_IOLBF | _IONBF))
        _fwalk(lbfflush);

    iop->_ptr = iop->_base;
    iop->_cnt = read(fileno(iop), (char *)iop->_base,
        (unsigned)((iop->_flag & _IONBF) ? 1 : iop->_bufsiz ));
    if (--iop->_cnt >= 0)       /* success */
        return (*iop->_ptr++);
    if (iop->_cnt != -1)        /* error */
        iop->_flag |= _IOERR;
    else {              /* end-of-file */
        iop->_flag |= _IOEOF;
        if (iop->_flag & _IORW)
            iop->_flag &= ~_IOREAD;
    }
    iop->_cnt = 0;
    return (EOF);
}

static void
lbfflush(FILE *iop)
{
    if (iop->_flag & _IOLBF)
        (void) fflush(iop);
}