reactos/lib/msvcrt/io/mktemp.c

   1 /*
   2  * COPYRIGHT:   See COPYING in the top level directory
   3  *              Copyright (C) 1994 DJ Delorie, see COPYING.DJ for details
   4  * PROJECT:     ReactOS system libraries
   5  * FILE:        lib/crtdll/io/mktemp.c
   6  * PURPOSE:     Makes a temp file based on a template
   7  * PROGRAMER:   DJ Delorie
   8                                 Boudewijn Dekker
   9  * UPDATE HISTORY:
  10  *              28/12/98: Appropriated for the Reactos Kernel
  11  */
  12
  13 /* Copyright (C) 1996 DJ Delorie, see COPYING.DJ for details */
  14 /* Copyright (C) 1995 DJ Delorie, see COPYING.DJ for details */
  15
  16 #include <msvcrt/stdio.h>
  17 #include <msvcrt/string.h>
  18 #include <msvcrt/io.h>
  19
  20
  21 char* _mktemp (char *_template)
  22 {
  23   static int count = 0;
  24   char *cp, *dp;
  25   int i, len, xcount, loopcnt;
  26
  27   len = strlen (_template);
  28   cp = _template + len;
  29
  30   xcount = 0;
  31   while (xcount < 6 && cp > _template && cp[-1] == 'X')
  32     xcount++, cp--;
  33
  34   if (xcount) {
  35     dp = cp;
  36     while (dp > _template && dp[-1] != '/' && dp[-1] != '\\' && dp[-1] != ':')
  37       dp--;
  38
  39     /* Keep the first characters of the template, but turn the rest into
  40        Xs.  */
  41     while (cp > dp + 8 - xcount) {
  42       *--cp = 'X';
  43       xcount = (xcount >= 6) ? 6 : 1 + xcount;
  44     }
  45
  46     /* If dots occur too early -- squash them.  */
  47     while (dp < cp) {
  48       if (*dp == '.') *dp = 'a';
  49       dp++;
  50     }
  51
  52     /* Try to add ".tmp" to the filename.  Truncate unused Xs.  */
  53     if (cp + xcount + 3 < _template + len)
  54       strcpy (cp + xcount, ".tmp");
  55     else
  56       cp[xcount] = 0;
  57
  58     /* This loop can run up to 2<<(5*6) times, or about 10^9 times.  */
  59     for (loopcnt = 0; loopcnt < (1 << (5 * xcount)); loopcnt++) {
  60       int c = count++;
  61       for (i = 0; i < xcount; i++, c >>= 5)
  62         cp[i] = "abcdefghijklmnopqrstuvwxyz012345"[c & 0x1f];
  63       if (_access(_template,0) == -1)
  64         return _template;
  65     }
  66   }
  67
  68   /* Failure:  truncate the template and return NULL.  */
  69   *_template = 0;
  70   return 0;
  71 }
  72
  73 wchar_t* _wmktemp (wchar_t *_template)
  74 {
  75   static int count = 0;
  76   wchar_t *cp, *dp;
  77   int i, len, xcount, loopcnt;
  78
  79   len = wcslen (_template);
  80   cp = _template + len;
  81
  82   xcount = 0;
  83   while (xcount < 6 && cp > _template && cp[-1] == L'X')
  84     xcount++, cp--;
  85
  86   if (xcount) {
  87     dp = cp;
  88     while (dp > _template && dp[-1] != L'/' && dp[-1] != L'\\' && dp[-1] != L':')
  89       dp--;
  90
  91     /* Keep the first characters of the template, but turn the rest into
  92        Xs.  */
  93     while (cp > dp + 8 - xcount) {
  94       *--cp = L'X';
  95       xcount = (xcount >= 6) ? 6 : 1 + xcount;
  96     }
  97
  98     /* If dots occur too early -- squash them.  */
  99     while (dp < cp) {
 100       if (*dp == L'.') *dp = L'a';
 101       dp++;
 102     }
 103
 104     /* Try to add ".tmp" to the filename.  Truncate unused Xs.  */
 105     if (cp + xcount + 3 < _template + len)
 106       wcscpy (cp + xcount, L".tmp");
 107     else
 108       cp[xcount] = 0;
 109
 110     /* This loop can run up to 2<<(5*6) times, or about 10^9 times.  */
 111     for (loopcnt = 0; loopcnt < (1 << (5 * xcount)); loopcnt++) {
 112       int c = count++;
 113       for (i = 0; i < xcount; i++, c >>= 5)
 114         cp[i] = L"abcdefghijklmnopqrstuvwxyz012345"[c & 0x1f];
 115       if (_waccess(_template,0) == -1)
 116         return _template;
 117     }
 118   }
 119
 120   /* Failure:  truncate the template and return NULL.  */
 121   *_template = 0;
 122   return 0;
 123 }