stdio/4.2/filbuf.c

	filbuf.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * 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 1986 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"  /* from S5R2 2.1 */


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

extern _findbuf();
extern int read();
extern int fflush();

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

int
_filbuf(iop)
register FILE *iop;
{

    if ( !(iop->_flag & _IOREAD) )
        if (iop->_flag & _IORW)
            iop->_flag |= _IOREAD;
        else
            return(EOF);

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

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

    if (iop == stdin) {
        if (stdout->_flag&_IOLBF)
            (void) fflush(stdout);
        if (stderr->_flag&_IOLBF)
            (void) fflush(stderr);
    }

    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);
}