dbm/src/mktemp.c

   1 /*
   2  * Copyright (c) 1987, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. ***REMOVED*** - see
  14  *    ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change
  15  * 4. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #if defined(LIBC_SCCS) && !defined(lint)
  33 static char sccsid[] = "@(#)mktemp.c    8.1 (Berkeley) 6/4/93";
  34 #endif /* LIBC_SCCS and not lint */
  35
  36 #ifdef macintosh
  37 #include <unix.h>
  38 #else
  39 #include <sys/types.h>
  40 #include <sys/stat.h>
  41 #endif
  42 #include <fcntl.h>
  43 #include <errno.h>
  44 #include <stdio.h>
  45 #include <ctype.h>
  46 #include "mcom_db.h"
  47
  48 #ifndef _WINDOWS
  49 #include <unistd.h>
  50 #endif
  51
  52 #ifdef _WINDOWS
  53 #include <process.h>
  54 #include "winfile.h"
  55 #endif
  56
  57 static int _gettemp(char *path, register int *doopen, int extraFlags);
  58
  59 int
  60 mkstemp(char *path)
  61 {
  62 #ifdef XP_OS2
  63         FILE *temp = tmpfile();
  64
  65         return (temp ? fileno(temp) : -1);
  66 #else
  67         int fd;
  68
  69         return (_gettemp(path, &fd, 0) ? fd : -1);
  70 #endif
  71 }
  72
  73 int
  74 mkstempflags(char *path, int extraFlags)
  75 {
  76         int fd;
  77
  78         return (_gettemp(path, &fd, extraFlags) ? fd : -1);
  79 }
  80
  81 #ifdef WINCE /* otherwise, use the one in libc */
  82 char *
  83 mktemp(char *path)
  84 {
  85         return(_gettemp(path, (int *)NULL, 0) ? path : (char *)NULL);
  86 }
  87 #endif
  88
  89 /* NB: This routine modifies its input string, and does not always restore it.
  90 ** returns 1 on success, 0 on failure.
  91 */
  92 static int
  93 _gettemp(char *path, register int *doopen, int extraFlags)
  94 {
  95 #if !defined(_WINDOWS) || defined(_WIN32)
  96         extern int errno;
  97 #endif
  98         register char *start, *trv;
  99         struct stat sbuf;
 100         unsigned int pid;
 101
 102         pid = getpid();
 103         for (trv = path; *trv; ++trv);          /* extra X's get set to 0's */
 104         while (*--trv == 'X') {
 105                 *trv = (pid % 10) + '0';
 106                 pid /= 10;
 107         }
 108
 109         /*
 110          * check the target directory; if you have six X's and it
 111          * doesn't exist this runs for a *very* long time.
 112          */
 113         for (start = trv + 1;; --trv) {
 114                 char saved;
 115                 if (trv <= path)
 116                         break;
 117                 saved = *trv;
 118                 if (saved == '/' || saved == '\\') {
 119                         int rv;
 120                         *trv = '\0';
 121                         rv = stat(path, &sbuf);
 122                         *trv = saved;
 123                         if (rv)
 124                                 return(0);
 125                         if (!S_ISDIR(sbuf.st_mode)) {
 126                                 errno = ENOTDIR;
 127                                 return(0);
 128                         }
 129                         break;
 130                 }
 131         }
 132
 133         for (;;) {
 134                 if (doopen) {
 135                         if ((*doopen =
 136                             open(path, O_CREAT|O_EXCL|O_RDWR|extraFlags, 0600)) >= 0)
 137                                 return(1);
 138                         if (errno != EEXIST)
 139                                 return(0);
 140                 }
 141                 else if (stat(path, &sbuf))
 142                         return(errno == ENOENT ? 1 : 0);
 143
 144                 /* tricky little algorithm for backward compatibility */
 145                 for (trv = start;;) {
 146                         if (!*trv)
 147                                 return(0);
 148                         if (*trv == 'z')
 149                                 *trv++ = 'a';
 150                         else {
 151                                 if (isdigit(*trv))
 152                                         *trv = 'a';
 153                                 else
 154                                         ++*trv;
 155                                 break;
 156                         }
 157                 }
 158         }
 159         /*NOTREACHED*/
 160 }