mktemp.c

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#if defined(LIBC_SCCS) && !defined(lint)
static const char sccsid[] = "@(#)mktemp.c	8.1 (Berkeley) 6/4/93";
static const char rcsid[] = "$Id: mktemp.c,v 1.1 2001/03/29 06:30:33 marka Exp $";
#endif /* LIBC_SCCS and not lint */

/*
 * Copyright (c) 1987, 1993
 *    The Regents of the University of California.  All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 * 	This product includes software developed by the University of
 * 	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
 * 
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies, and that
 * the name of Digital Equipment Corporation not be used in advertising or
 * publicity pertaining to distribution of the document or software without
 * specific, written prior permission.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

#include "port_before.h"

#include <sys/types.h>
#include <sys/stat.h>

#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>

#include "port_after.h"

#if (!defined(NEED_MKTEMP)) && (!defined(NEED_MKSTEMP))
int __mktemp_unneeded__;
#else

static int gettemp(char *path, int *doopen);

#ifdef NEED_MKSTEMP
mkstemp(char *path) {
	int fd;

	return (gettemp(path, &fd) ? fd : -1);
}
#endif

#ifdef NEED_MKTEMP
char *
mktemp(char *path) {
	return(gettemp(path, (int *)NULL) ? path : (char *)NULL);
}
#endif

static int
gettemp(char *path, int *doopen) {
	char *start, *trv;
	struct stat sbuf;
	u_int pid;

	pid = getpid();
	for (trv = path; *trv; ++trv);		/* extra X's get set to 0's */
	while (*--trv == 'X') {
		*trv = (pid % 10) + '0';
		pid /= 10;
	}

	/*
	 * check the target directory; if you have six X's and it
	 * doesn't exist this runs for a *very* long time.
	 */
	for (start = trv + 1;; --trv) {
		if (trv <= path)
			break;
		if (*trv == '/') {
			*trv = '\0';
			if (stat(path, &sbuf))
				return(0);
			if (!S_ISDIR(sbuf.st_mode)) {
				errno = ENOTDIR;
				return(0);
			}
			*trv = '/';
			break;
		}
	}

	for (;;) {
		if (doopen) {
			if ((*doopen =
			    open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0)
				return(1);
			if (errno != EEXIST)
				return(0);
		}
		else if (stat(path, &sbuf))
			return(errno == ENOENT ? 1 : 0);

		/* tricky little algorithm for backward compatibility */
		for (trv = start;;) {
			if (!*trv)
				return(0);
			if (*trv == 'z')
				*trv++ = 'a';
			else {
				if (isdigit(*trv))
					*trv = 'a';
				else
					++*trv;
				break;
			}
		}
	}
	/*NOTREACHED*/
}

#endif /*NEED_MKTEMP*/