reactos/lib/crtdll/time/strftime.c

   1 /* Copyright (C) 1994 DJ Delorie, see COPYING.DJ for details */
   2 #include <crtdll/string.h>
   3 #include <crtdll/time.h>
   4 #include <crtdll/stdlib.h>
   5 #include <crtdll/wchar.h>
   6
   7 #define TM_YEAR_BASE 1900
   8
   9 static const char *afmt[] = {
  10   "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat",
  11 };
  12 static const char *Afmt[] = {
  13   "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday",
  14   "Saturday",
  15 };
  16 static const char *bfmt[] = {
  17   "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep",
  18   "Oct", "Nov", "Dec",
  19 };
  20 static const char *Bfmt[] = {
  21   "January", "February", "March", "April", "May", "June", "July",
  22   "August", "September", "October", "November", "December",
  23 };
  24
  25 static size_t gsize;
  26 static char *pt;
  27
  28 static int
  29 _add(const char *str)
  30 {
  31   for (;; ++pt, --gsize)
  32   {
  33     if (!gsize)
  34       return 0;
  35     if (!(*pt = *str++))
  36       return 1;
  37   }
  38 }
  39
  40 static int
  41 _conv(int n, int digits, char pad)
  42 {
  43   static char buf[10];
  44   char *p;
  45
  46   for (p = buf + sizeof(buf) - 2; n > 0 && p > buf; n /= 10, --digits)
  47     *p-- = n % 10 + '0';
  48   while (p > buf && digits-- > 0)
  49     *p-- = pad;
  50   return _add(++p);
  51 }
  52
  53 static size_t
  54 _fmt(const char *format, const struct tm *t)
  55 {
  56   for (; *format; ++format)
  57   {
  58     if (*format == '%') {
  59         if (*(format+1) == '#' ) {format++;}
  60
  61       switch(*++format)
  62       {
  63       case '\0':
  64         --format;
  65         break;
  66       case 'A':
  67         if (t->tm_wday < 0 || t->tm_wday > 6)
  68           return 0;
  69         if (!_add(Afmt[t->tm_wday]))
  70           return 0;
  71         continue;
  72       case 'a':
  73         if (t->tm_wday < 0 || t->tm_wday > 6)
  74           return 0;
  75         if (!_add(afmt[t->tm_wday]))
  76           return 0;
  77         continue;
  78       case 'B':
  79         if (t->tm_mon < 0 || t->tm_mon > 11)
  80           return 0;
  81         if (!_add(Bfmt[t->tm_mon]))
  82           return 0;
  83         continue;
  84       case 'b':
  85       case 'h':
  86         if (t->tm_mon < 0 || t->tm_mon > 11)
  87           return 0;
  88         if (!_add(bfmt[t->tm_mon]))
  89           return 0;
  90         continue;
  91       case 'C':
  92         if (!_fmt("%a %b %e %H:%M:%S %Y", t))
  93           return 0;
  94         continue;
  95       case 'c':
  96         if (!_fmt("%m/%d/%y %H:%M:%S", t))
  97           return 0;
  98         continue;
  99       case 'e':
 100         if (!_conv(t->tm_mday, 2, ' '))
 101           return 0;
 102         continue;
 103       case 'D':
 104         if (!_fmt("%m/%d/%y", t))
 105           return 0;
 106         continue;
 107       case 'd':
 108         if (!_conv(t->tm_mday, 2, '0'))
 109           return 0;
 110         continue;
 111       case 'H':
 112         if (!_conv(t->tm_hour, 2, '0'))
 113           return 0;
 114         continue;
 115       case 'I':
 116         if (!_conv(t->tm_hour % 12 ?
 117                    t->tm_hour % 12 : 12, 2, '0'))
 118           return 0;
 119         continue;
 120       case 'j':
 121         if (!_conv(t->tm_yday + 1, 3, '0'))
 122           return 0;
 123         continue;
 124       case 'k':
 125         if (!_conv(t->tm_hour, 2, ' '))
 126           return 0;
 127         continue;
 128       case 'l':
 129         if (!_conv(t->tm_hour % 12 ?
 130                    t->tm_hour % 12 : 12, 2, ' '))
 131           return 0;
 132         continue;
 133       case 'M':
 134         if (!_conv(t->tm_min, 2, '0'))
 135           return 0;
 136         continue;
 137       case 'm':
 138         if (!_conv(t->tm_mon + 1, 2, '0'))
 139           return 0;
 140         continue;
 141       case 'n':
 142         if (!_add("\n"))
 143           return 0;
 144         continue;
 145       case 'p':
 146         if (!_add(t->tm_hour >= 12 ? "PM" : "AM"))
 147           return 0;
 148         continue;
 149       case 'R':
 150         if (!_fmt("%H:%M", t))
 151           return 0;
 152         continue;
 153       case 'r':
 154         if (!_fmt("%I:%M:%S %p", t))
 155           return 0;
 156         continue;
 157       case 'S':
 158         if (!_conv(t->tm_sec, 2, '0'))
 159           return 0;
 160         continue;
 161       case 'T':
 162       case 'X':
 163         if (!_fmt("%H:%M:%S", t))
 164           return 0;
 165         continue;
 166       case 't':
 167         if (!_add("\t"))
 168           return 0;
 169         continue;
 170       case 'U':
 171         if (!_conv((t->tm_yday + 7 - t->tm_wday) / 7,
 172                    2, '0'))
 173           return 0;
 174         continue;
 175       case 'W':
 176         if (!_conv((t->tm_yday + 7 -
 177                     (t->tm_wday ? (t->tm_wday - 1) : 6))
 178                    / 7, 2, '0'))
 179           return 0;
 180         continue;
 181       case 'w':
 182         if (!_conv(t->tm_wday, 1, '0'))
 183           return 0;
 184         continue;
 185       case 'x':
 186         if (!_fmt("%m/%d/%y", t))
 187           return 0;
 188         continue;
 189       case 'y':
 190         if (!_conv((t->tm_year + TM_YEAR_BASE)
 191                    % 100, 2, '0'))
 192           return 0;
 193         continue;
 194       case 'Y':
 195         if (!_conv(t->tm_year + TM_YEAR_BASE, 4, '0'))
 196           return 0;
 197         continue;
 198       case 'Z':
 199         if (!t->tm_zone || !_add(t->tm_zone))
 200           return 0;
 201         continue;
 202       case '%':
 203         /*
 204          * X311J/88-090 (4.12.3.5): if conversion char is
 205          * undefined, behavior is undefined.  Print out the
 206          * character itself as printf(3) does.
 207          */
 208       default:
 209         break;
 210       }
 211     }
 212     if (!gsize--)
 213       return 0;
 214     *pt++ = *format;
 215   }
 216   return gsize;
 217 }
 218
 219 size_t
 220 strftime(char *s, size_t maxsize, const char *format, const struct tm *t)
 221 {
 222   pt = s;
 223   if ((gsize = maxsize) < 1)
 224     return 0;
 225   if (_fmt(format, t))
 226   {
 227     *pt = '\0';
 228     return maxsize - gsize;
 229   }
 230   return 0;
 231 }
 232
 233 size_t
 234 wcsftime(wchar_t *s, size_t maxsize, const wchar_t *format, const struct tm *t)
 235 {
 236   char *x;
 237   char *f;
 238   int i,j;
 239   x = malloc(maxsize);
 240   j = wcslen(format);
 241   f = malloc(j+1);
 242   for(i=0;i<j;i++)
 243         f[i] = (char)*format;
 244   f[i] = 0;
 245   pt = x;
 246   if ((gsize = maxsize) < 1)
 247     return 0;
 248   if (_fmt(f, t))
 249   {
 250     *pt = '\0';
 251     free(f);
 252     for(i=0;i<maxsize;i++)
 253         s[i] = (wchar_t)x[i];
 254     s[i] = 0;
 255     free(x);
 256     return maxsize - gsize;
 257   }
 258   for(i=0;i<maxsize;i++)
 259         s[i] = (wchar_t)x[i];
 260   s[i] = 0;
 261   free(f);
 262   free(x);
 263   return 0;
 264 }