usr/src/lib/libresolv2/common/bsd/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. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 /*
  35  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
  36  *
  37  * Permission to use, copy, modify, and distribute this software for any
  38  * purpose with or without fee is hereby granted, provided that the above
  39  * copyright notice and this permission notice appear in all copies, and that
  40  * the name of Digital Equipment Corporation not be used in advertising or
  41  * publicity pertaining to distribution of the document or software without
  42  * specific, written prior permission.
  43  *
  44  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
  45  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
  46  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
  47  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  48  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  49  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  50  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  51  * SOFTWARE.
  52  */
  53
  54 #include "port_before.h"
  55
  56 #include <sys/types.h>
  57 #include <sys/stat.h>
  58
  59 #include <ctype.h>
  60 #include <errno.h>
  61 #include <fcntl.h>
  62 #include <stdio.h>
  63
  64 #include "port_after.h"
  65
  66 #if (!defined(NEED_MKTEMP)) && (!defined(NEED_MKSTEMP))
  67 int __mktemp_unneeded__;
  68 #else
  69
  70 static int gettemp(char *path, int *doopen);
  71
  72 #ifdef NEED_MKSTEMP
  73 mkstemp(char *path) {
  74         int fd;
  75
  76         return (gettemp(path, &fd) ? fd : -1);
  77 }
  78 #endif
  79
  80 #ifdef NEED_MKTEMP
  81 char *
  82 mktemp(char *path) {
  83         return(gettemp(path, (int *)NULL) ? path : (char *)NULL);
  84 }
  85 #endif
  86
  87 static int
  88 gettemp(char *path, int *doopen) {
  89         char *start, *trv;
  90         struct stat sbuf;
  91         u_int pid;
  92
  93         pid = getpid();
  94         for (trv = path; *trv; ++trv);          /*%< extra X's get set to 0's */
  95         while (*--trv == 'X') {
  96                 *trv = (pid % 10) + '0';
  97                 pid /= 10;
  98         }
  99
 100         /*
 101          * check the target directory; if you have six X's and it
 102          * doesn't exist this runs for a *very* long time.
 103          */
 104         for (start = trv + 1;; --trv) {
 105                 if (trv <= path)
 106                         break;
 107                 if (*trv == '/') {
 108                         *trv = '\0';
 109                         if (stat(path, &sbuf))
 110                                 return(0);
 111                         if (!S_ISDIR(sbuf.st_mode)) {
 112                                 errno = ENOTDIR;
 113                                 return(0);
 114                         }
 115                         *trv = '/';
 116                         break;
 117                 }
 118         }
 119
 120         for (;;) {
 121                 if (doopen) {
 122                         if ((*doopen =
 123                             open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0)
 124                                 return(1);
 125                         if (errno != EEXIST)
 126                                 return(0);
 127                 }
 128                 else if (stat(path, &sbuf))
 129                         return(errno == ENOENT ? 1 : 0);
 130
 131                 /* tricky little algorithm for backward compatibility */
 132                 for (trv = start;;) {
 133                         if (!*trv)
 134                                 return(0);
 135                         if (*trv == 'z')
 136                                 *trv++ = 'a';
 137                         else {
 138                                 if (isdigit(*trv))
 139                                         *trv = 'a';
 140                                 else
 141                                         ++*trv;
 142                                 break;
 143                         }
 144                 }
 145         }
 146         /*NOTREACHED*/
 147 }
 148
 149 #endif /*NEED_MKTEMP*/
 150
 151 /*! \file */