StdLib/LibC/Stdio/gettemp.c

   1 /** @file
   2   Internal function to generate temporary file name for tmpnam.
   3
   4   Copyright (c) 2010, Intel Corporation. All rights reserved.<BR>
   5   This program and the accompanying materials are licensed and made available
   6   under the terms and conditions of the BSD License that accompanies this
   7   distribution.  The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php.
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13   Copyright (c) 1987, 1993
  14    The Regents of the University of California.  All rights reserved.
  15
  16   Redistribution and use in source and binary forms, with or without
  17   modification, are permitted provided that the following conditions
  18   are met:
  19     1. Redistributions of source code must retain the above copyright
  20        notice, this list of conditions and the following disclaimer.
  21     2. Redistributions in binary form must reproduce the above copyright
  22        notice, this list of conditions and the following disclaimer in the
  23        documentation and/or other materials provided with the distribution.
  24     3. Neither the name of the University nor the names of its contributors
  25        may be used to endorse or promote products derived from this software
  26        without specific prior written permission.
  27
  28   THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  29   ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  30   IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  31   ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  32   FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  33   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  34   OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  35   HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  36   LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  37   OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  38   SUCH DAMAGE.
  39
  40   NetBSD: gettemp.c,v 1.13 2003/12/05 00:57:36 uebayasi Exp
  41 **/
  42 #include  <LibConfig.h>
  43
  44 #if HAVE_NBTOOL_CONFIG_H
  45 #include "nbtool_config.h"
  46 #endif
  47
  48 #if !defined(HAVE_NBTOOL_CONFIG_H) || !defined(HAVE_MKSTEMP) || !defined(HAVE_MKDTEMP)
  49
  50 #include <sys/EfiCdefs.h>
  51 #if defined(LIBC_SCCS) && !defined(lint)
  52 #if 0
  53 static char sccsid[] = "@(#)mktemp.c  8.1 (Berkeley) 6/4/93";
  54 #else
  55 __RCSID("$NetBSD: gettemp.c,v 1.13 2003/12/05 00:57:36 uebayasi Exp $");
  56 #endif
  57 #endif /* LIBC_SCCS and not lint */
  58
  59 #include <sys/types.h>
  60 #include <sys/stat.h>
  61
  62 #include <assert.h>
  63 #include <ctype.h>
  64 #include <errno.h>
  65 #include <fcntl.h>
  66 #include <stdio.h>
  67 #include <stdlib.h>
  68 #include <sys/EfiSysCall.h>
  69
  70 #if HAVE_NBTOOL_CONFIG_H
  71 #define GETTEMP   gettemp
  72 #else
  73 #include "reentrant.h"
  74 #include "local.h"
  75 #define GETTEMP   __gettemp
  76 #endif
  77
  78 int
  79 GETTEMP(
  80   char *path,
  81   int *doopen,
  82   int domkdir
  83   )
  84 {
  85   char *start, *trv;
  86   struct stat sbuf;
  87
  88   /* To guarantee multiple calls generate unique names even if
  89      the file is not created. 676 different possibilities with 7
  90      or more X's, 26 with 6 or less. */
  91   static char xtra[] = "aa";
  92   int xcnt = 0;
  93
  94   _DIAGASSERT(path != NULL);
  95   /* doopen may be NULL */
  96
  97   /* Move to end of path and count trailing X's. */
  98   for (trv = path; *trv; ++trv) {
  99     if (*trv == 'X') {
 100       xcnt++;
 101     }
 102     else {
 103       xcnt = 0;
 104     }
 105   }
 106
 107   /* Use at least one from xtra.  Use 2 if more than 6 X's. */
 108   if (*(trv - 1) == 'X')
 109     *--trv = xtra[0];
 110   if (xcnt > 6 && *(trv - 1) == 'X')
 111     *--trv = xtra[1];
 112
 113   /* Set remaining X's to 0's. */
 114   while (*--trv == 'X') {
 115     *trv = '0';
 116   }
 117
 118   /* update xtra for next call. */
 119   if (xtra[0] != 'z')
 120     xtra[0]++;
 121   else {
 122     xtra[0] = 'a';
 123     if (xtra[1] != 'z')
 124       xtra[1]++;
 125     else
 126       xtra[1] = 'a';
 127   }
 128
 129   /*
 130    * check the target directory; if you have six X's and it
 131    * doesn't exist this runs for a *very* long time.
 132    */
 133   for (start = trv + 1;; --trv) {
 134     if (trv <= path)
 135       break;
 136     if (*trv == '/') {
 137       *trv = '\0';
 138       if (stat(path, &sbuf))
 139         return (0);
 140       if (!S_ISDIR(sbuf.st_mode)) {
 141         errno = ENOTDIR;
 142         return (0);
 143       }
 144       *trv = '/';
 145       break;
 146     }
 147   }
 148
 149   for (;;) {
 150     if (doopen) {
 151       if ((*doopen =
 152           open(path, O_CREAT | O_EXCL | O_RDWR, 0600)) >= 0)
 153         return (1);
 154       if (errno != EEXIST)
 155         return (0);
 156     } else if (domkdir) {
 157       if (mkdir(path, 0700) >= 0)
 158         return (1);
 159       if (errno != EEXIST)
 160         return (0);
 161     } else if (lstat(path, &sbuf))
 162       return (errno == ENOENT ? 1 : 0);
 163
 164     /* tricky little algorithm for backward compatibility */
 165     for (trv = start;;) {
 166       if (!*trv)
 167         return (0);
 168       if (*trv == 'z') {
 169         *trv++ = 'a';
 170       }
 171       else {
 172         if (isdigit((unsigned char)*trv))
 173           *trv = 'a';
 174         else
 175           ++*trv;
 176         break;
 177       }
 178     }
 179   }
 180   /*NOTREACHED*/
 181 }
 182
 183 #endif /* !HAVE_NBTOOL_CONFIG_H || !HAVE_MKSTEMP || !HAVE_MKDTEMP */