port/gen/mkstemp.c

	mkstemp.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 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T
 * All Rights Reserved
 *
 * Portions of this source code were derived from Berkeley
 * 4.3 BSD under license from the regents of the University of
 * California.
 */

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

#include <sys/feature_tests.h>

#if !defined(_LP64) && _FILE_OFFSET_BITS == 64
#pragma weak mkstemp64 = _mkstemp64
#define _mkstemp    _mkstemp64
#else
#pragma weak mkstemp = _mkstemp
#endif

#include "synonyms.h"
#include <sys/fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <alloca.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>


int
_mkstemp(char *as)
{
    int fd;
    char    *tstr, *str, *mkret;

    if (as == NULL || *as == NULL)
        return (-1);

    tstr = alloca(strlen(as) + 1);
    (void) strcpy(tstr, as);

    str = tstr + (strlen(tstr) - 1);

    /*
     * The following for() loop is doing work.  mktemp() will generate
     * a different name each time through the loop.  So if the first
     * name is used then keep trying until you find a free filename.
     */

    for (; ; ) {
        if (*str == 'X') { /* If no trailing X's don't call mktemp. */
            mkret = mktemp(as);
            if (*mkret == '\0') {
                return (-1);
            }
        }
#if _FILE_OFFSET_BITS == 64
        if ((fd = open64(as, O_CREAT|O_EXCL|O_RDWR, 0600)) != -1) {
            return (fd);
        }
#else
        if ((fd = open(as, O_CREAT|O_EXCL|O_RDWR, 0600)) != -1) {
            return (fd);
        }
#endif  /* _FILE_OFFSET_BITS == 64 */

        /*
         * If the error condition is other than EEXIST or if the
         * file exists and there are no X's in the string
         * return -1.
         */

        if ((errno != EEXIST) || (*str != 'X')) {
            return (-1);
        }
        (void) strcpy(as, tstr);
    }
}