port/stdio/fopen.c

/*
 * 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 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*  Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */

/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

/*LINTLIBRARY*/

#include <sys/types.h>
#include "file64.h"
#include <stdio.h>
#include <sys/fcntl.h>
#include <unistd.h>
#include <sys/file.h>
#include "stdiom.h"

/* Final argument to _endopen depends on build environment */
#define ALWAYS_LARGE_OPEN   1
#define LARGE_OPEN  (_FILE_OFFSET_BITS == 64)

static FILE *
_endopen(const char *file, const char *mode, FILE *iop, int largefile)
{
    int plus, oflag, fd;

    if (iop == NULL || file == NULL || file[0] == '\0')
        return (NULL);
    plus = (mode[1] == '+');
    switch (mode[0]) {
    case 'w':
        oflag = (plus ? O_RDWR : O_WRONLY) | O_TRUNC | O_CREAT;
        break;
    case 'a':
        oflag = (plus ? O_RDWR : O_WRONLY) | O_CREAT;
        break;
    case 'r':
        oflag = plus ? O_RDWR : O_RDONLY;
        break;
    default:
        return (NULL);
    }

    if (largefile) {
        fd = open64(file, oflag, 0666); /* mapped to open() for V9 */
    } else {
        fd = open(file, oflag, 0666);
    }
    if (fd < 0)
        return (NULL);
    iop->_cnt = 0;
#ifdef _LP64
    iop->_file = fd;
#else
    if (fd <= _FILE_FD_MAX) {
        SET_FILE(iop, fd);
    } else if (_file_set(iop, fd, mode) != 0) {
        /* errno set in _file_set() */
        (void) close(fd);
        return (NULL);
    }
#endif
    iop->_flag = plus ? _IORW : (mode[0] == 'r') ? _IOREAD : _IOWRT;
    if (mode[0] == 'a')   {
        if ((lseek64(fd, 0L, SEEK_END)) < 0)  {
            (void) close(fd);
            return (NULL);
        }
    }
    iop->_base = iop->_ptr = NULL;
    /*
     * Sys5 does not support _bufsiz
     *
     * iop->_bufsiz = 0;
     */
    return (iop);
}

FILE *
fopen(const char *file, const char *mode)
{
    FILE    *iop;
    FILE    *rc;

    iop = _findiop();
    rc = _endopen(file, mode, iop, LARGE_OPEN);
    if (rc == NULL && iop != NULL)
        iop->_flag = 0; /* release iop */
    return (rc);
}

/*
 * For _LP64, all fopen() calls are 64-bit calls, i.e., open64() system call.
 * There should not be fopen64() calls.
 * Similar for freopen64().
 */
#if !defined(_LP64)
FILE *
fopen64(const char *file, const char *mode)
{
    FILE    *iop;
    FILE    *rc;

    iop = _findiop();
    rc = _endopen(file, mode, iop, ALWAYS_LARGE_OPEN);
    if (rc == NULL && iop != NULL)
        iop->_flag = 0; /* release iop */
    return (rc);
}
#endif

FILE *
freopen(const char *file, const char *mode, FILE *iop)
{
    (void) fclose(iop); /* doesn't matter if this fails */
    return (_endopen(file, mode, iop, LARGE_OPEN));
}

#if !defined(_LP64)
FILE *
freopen64(const char *file, const char *mode, FILE *iop)
{
    (void) fclose(iop); /* doesn't matter if this fails */
    return (_endopen(file, mode, iop, ALWAYS_LARGE_OPEN));
}
#endif