/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (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 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1988 AT&T */
/*        All Rights Reserved   */

#include "lint.h"
#include "file64.h"
#include "mtlib.h"
#include <stdio.h>
#include <memory.h>
#include <errno.h>
#include <thread.h>
#include <synch.h>
#include <sys/types.h>
#include "stdiom.h"
#include "mse.h"

/* read size-max line from stream, including '\n' */
char *
fgets(char *buf, int size, FILE *iop)
{
        char *ptr = buf;
        int n;
        Uchar *bufend;
        char *p;
        rmutex_t *lk;

        FLOCKFILE(lk, iop);

        _SET_ORIENTATION_BYTE(iop);

        if (!(iop->_flag & (_IOREAD | _IORW))) {
                errno = EBADF;
                FUNLOCKFILE(lk);
                return (NULL);
        }

        if (iop->_base == NULL) {
                if ((bufend = _findbuf(iop)) == NULL) {
                        FUNLOCKFILE(lk);
                        return (NULL);
                }
        }
        else
                bufend = _bufend(iop);

        size--;         /* room for '\0' */
        while (size > 0) {
                /* empty buffer */
                if (iop->_cnt <= 0) {
                        if (__filbuf(iop) != EOF) {
                                iop->_ptr--;    /* put back the character */
                                iop->_cnt++;
                        } else if (ptr == buf) {  /* never read anything */
                                FUNLOCKFILE(lk);
                                return (NULL);
                        } else
                                break;          /* nothing left to read */
                }
                n = (int)(size < iop->_cnt ? size : iop->_cnt);
                if ((p = memccpy(ptr, (char *)iop->_ptr, '\n',
                    (size_t)n)) != NULL)
                        n = (int)(p - ptr);
                ptr += n;
                iop->_cnt -= n;
                iop->_ptr += n;
                if (_needsync(iop, bufend))
                        _bufsync(iop, bufend);
                if (p != NULL)
                        break; /* newline found */
                size -= n;
        }
        FUNLOCKFILE(lk);
        *ptr = '\0';
        return (buf);
}