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 #include "watcomfx.h"
  37
  38 #ifdef macintosh
  39 #include <unix.h>
  40 #else
  41 #include <sys/types.h>
  42 #include <sys/stat.h>
  43 #endif
  44 #include <fcntl.h>
  45 #include <errno.h>
  46 #include <stdio.h>
  47 #include <ctype.h>
  48 #include "mcom_db.h"
  49
  50 #if !defined(_WINDOWS) && !defined(XP_OS2_VACPP)
  51 #include <unistd.h>
  52 #endif
  53
  54 #ifdef XP_OS2_VACPP
  55 #include <process.h>
  56 #endif
  57
  58 #ifdef _WINDOWS
  59 #include <process.h>
  60 #include "winfile.h"
  61 #endif
  62
  63 static int _gettemp(char *path, register int *doopen, int extraFlags);
  64
  65 int
  66 mkstemp(char *path)
  67 {
  68 #ifdef XP_OS2
  69         FILE *temp = tmpfile();
  70
  71         return (temp ? fileno(temp) : -1);
  72 #else
  73         int fd;
  74
  75         return (_gettemp(path, &fd, 0) ? fd : -1);
  76 #endif
  77 }
  78
  79 int
  80 mkstempflags(char *path, int extraFlags)
  81 {
  82         int fd;
  83
  84         return (_gettemp(path, &fd, extraFlags) ? fd : -1);
  85 }
  86
  87 char *
  88 mktemp(char *path)
  89 {
  90         return(_gettemp(path, (int *)NULL, 0) ? path : (char *)NULL);
  91 }
  92
  93 /* NB: This routine modifies its input string, and does not always restore it.
  94 ** returns 1 on success, 0 on failure.
  95 */
  96 static int
  97 _gettemp(char *path, register int *doopen, int extraFlags)
  98 {
  99 #if !defined(_WINDOWS) || defined(_WIN32)
 100         extern int errno;
 101 #endif
 102         register char *start, *trv;
 103         struct stat sbuf;
 104         unsigned int pid;
 105
 106         pid = getpid();
 107         for (trv = path; *trv; ++trv);          /* extra X's get set to 0's */
 108         while (*--trv == 'X') {
 109                 *trv = (pid % 10) + '0';
 110                 pid /= 10;
 111         }
 112
 113         /*
 114          * check the target directory; if you have six X's and it
 115          * doesn't exist this runs for a *very* long time.
 116          */
 117         for (start = trv + 1;; --trv) {
 118                 char saved;
 119                 if (trv <= path)
 120                         break;
 121                 saved = *trv;
 122                 if (saved == '/' || saved == '\\') {
 123                         int rv;
 124                         *trv = '\0';
 125                         rv = stat(path, &sbuf);
 126                         *trv = saved;
 127                         if (rv)
 128                                 return(0);
 129                         if (!S_ISDIR(sbuf.st_mode)) {
 130                                 errno = ENOTDIR;
 131                                 return(0);
 132                         }
 133                         break;
 134                 }
 135         }
 136
 137         for (;;) {
 138                 if (doopen) {
 139                         if ((*doopen =
 140                             open(path, O_CREAT|O_EXCL|O_RDWR|extraFlags, 0600)) >= 0)
 141                                 return(1);
 142                         if (errno != EEXIST)
 143                                 return(0);
 144                 }
 145                 else if (stat(path, &sbuf))
 146                         return(errno == ENOENT ? 1 : 0);
 147
 148                 /* tricky little algorithm for backward compatibility */
 149                 for (trv = start;;) {
 150                         if (!*trv)
 151                                 return(0);
 152                         if (*trv == 'z')
 153                                 *trv++ = 'a';
 154                         else {
 155                                 if (isdigit(*trv))
 156                                         *trv = 'a';
 157                                 else
 158                                         ++*trv;
 159                                 break;
 160                         }
 161                 }
 162         }
 163         /*NOTREACHED*/
 164 }