Colony » Colony Scout

/*

 * 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. 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.

 */

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

#include <errno.h>

#include <stdio.h>

#include <ctype.h>

#include <unistd.h>

static int _gettemp(char *, int *);

int

mkstemp(path)

        char *path;

{

        int fd;

        return (_gettemp(path, &fd) ? fd : -1);

}

char *

mktemp(path)

        char *path;

{

        return(_gettemp(path, (int *)NULL) ? path : (char *)NULL);

}

static int

_gettemp(path, doopen)

        char *path;

        int *doopen;

{

        extern int errno;

        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((unsigned char)*trv))

                                        *trv = 'a';

                                else

                                        ++*trv;

                                break;

                        }

                }

        }

        /*NOTREACHED*/

}