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   1 /*
   2  * Copyright (c) 1989 The Regents of the University of California.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms are permitted
   6  * provided that: (1) source distributions retain this entire copyright
   7  * notice and comment, and (2) distributions including binaries display
   8  * the following acknowledgement:  ``This product includes software
   9  * developed by the University of California, Berkeley and its contributors''
  10  * in the documentation or other materials provided with the distribution
  11  * and in all advertising materials mentioning features or use of this
  12  * software. Neither the name of the University nor the names of its
  13  * contributors may be used to endorse or promote products derived
  14  * from this software without specific prior written permission.
  15  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  17  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  18  */
  19
  20 #if defined(LIBC_SCCS) && !defined(lint)
  21 static char sccsid[] = "@(#)strftime.c  5.8 (Berkeley) 6/1/90";
  22 #endif /* LIBC_SCCS and not lint */
  23
  24 #include <sys/types.h>
  25 #include <sys/time.h>
  26 #ifndef linux
  27 # include <tzfile.h>
  28 #endif  /* linux */
  29 #include <string.h>
  30
  31 static char *afmt[] = {
  32         "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat",
  33 };
  34 static char *Afmt[] = {
  35         "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday",
  36         "Saturday",
  37 };
  38 static char *bfmt[] = {
  39         "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep",
  40         "Oct", "Nov", "Dec",
  41 };
  42 static char *Bfmt[] = {
  43         "January", "February", "March", "April", "May", "June", "July",
  44         "August", "September", "October", "November", "December",
  45 };
  46
  47 static size_t gsize;
  48 static char *pt;
  49
  50 size_t
  51 strftime(s, maxsize, format, t)
  52         char *s;
  53         char *format;
  54         size_t maxsize;
  55         struct tm *t;
  56 {
  57         size_t _fmt();
  58
  59         pt = s;
  60         if ((gsize = maxsize) < 1)
  61                 return(0);
  62         if (_fmt(format, t)) {
  63                 *pt = '\0';
  64                 return(maxsize - gsize);
  65         }
  66         return(0);
  67 }
  68
  69 static size_t
  70 _fmt(format, t)
  71         register char *format;
  72         struct tm *t;
  73 {
  74         for (; *format; ++format) {
  75                 if (*format == '%')
  76                         switch(*++format) {
  77                         case '\0':
  78                                 --format;
  79                                 break;
  80                         case 'A':
  81                                 if (t->tm_wday < 0 || t->tm_wday > 6)
  82                                         return(0);
  83                                 if (!_add(Afmt[t->tm_wday]))
  84                                         return(0);
  85                                 continue;
  86                         case 'a':
  87                                 if (t->tm_wday < 0 || t->tm_wday > 6)
  88                                         return(0);
  89                                 if (!_add(afmt[t->tm_wday]))
  90                                         return(0);
  91                                 continue;
  92                         case 'B':
  93                                 if (t->tm_mon < 0 || t->tm_mon > 11)
  94                                         return(0);
  95                                 if (!_add(Bfmt[t->tm_mon]))
  96                                         return(0);
  97                                 continue;
  98                         case 'b':
  99                         case 'h':
 100                                 if (t->tm_mon < 0 || t->tm_mon > 11)
 101                                         return(0);
 102                                 if (!_add(bfmt[t->tm_mon]))
 103                                         return(0);
 104                                 continue;
 105                         case 'C':
 106                                 if (!_fmt("%a %b %e %H:%M:%S %Y", t))
 107                                         return(0);
 108                                 continue;
 109                         case 'c':
 110                                 if (!_fmt("%m/%d/%y %H:%M:%S", t))
 111                                         return(0);
 112                                 continue;
 113                         case 'e':
 114                                 if (!_conv(t->tm_mday, 2, ' '))
 115                                         return(0);
 116                                 continue;
 117                         case 'D':
 118                                 if (!_fmt("%m/%d/%y", t))
 119                                         return(0);
 120                                 continue;
 121                         case 'd':
 122                                 if (!_conv(t->tm_mday, 2, '0'))
 123                                         return(0);
 124                                 continue;
 125                         case 'H':
 126                                 if (!_conv(t->tm_hour, 2, '0'))
 127                                         return(0);
 128                                 continue;
 129                         case 'I':
 130                                 if (!_conv(t->tm_hour % 12 ?
 131                                     t->tm_hour % 12 : 12, 2, '0'))
 132                                         return(0);
 133                                 continue;
 134                         case 'j':
 135                                 if (!_conv(t->tm_yday + 1, 3, '0'))
 136                                         return(0);
 137                                 continue;
 138                         case 'k':
 139                                 if (!_conv(t->tm_hour, 2, ' '))
 140                                         return(0);
 141                                 continue;
 142                         case 'l':
 143                                 if (!_conv(t->tm_hour % 12 ?
 144                                     t->tm_hour % 12 : 12, 2, ' '))
 145                                         return(0);
 146                                 continue;
 147                         case 'M':
 148                                 if (!_conv(t->tm_min, 2, '0'))
 149                                         return(0);
 150                                 continue;
 151                         case 'm':
 152                                 if (!_conv(t->tm_mon + 1, 2, '0'))
 153                                         return(0);
 154                                 continue;
 155                         case 'n':
 156                                 if (!_add("\n"))
 157                                         return(0);
 158                                 continue;
 159                         case 'p':
 160                                 if (!_add(t->tm_hour >= 12 ? "PM" : "AM"))
 161                                         return(0);
 162                                 continue;
 163                         case 'R':
 164                                 if (!_fmt("%H:%M", t))
 165                                         return(0);
 166                                 continue;
 167                         case 'r':
 168                                 if (!_fmt("%I:%M:%S %p", t))
 169                                         return(0);
 170                                 continue;
 171                         case 'S':
 172                                 if (!_conv(t->tm_sec, 2, '0'))
 173                                         return(0);
 174                                 continue;
 175                         case 'T':
 176                         case 'X':
 177                                 if (!_fmt("%H:%M:%S", t))
 178                                         return(0);
 179                                 continue;
 180                         case 't':
 181                                 if (!_add("\t"))
 182                                         return(0);
 183                                 continue;
 184                         case 'U':
 185                                 if (!_conv((t->tm_yday + 7 - t->tm_wday) / 7,
 186                                     2, '0'))
 187                                         return(0);
 188                                 continue;
 189                         case 'W':
 190                                 if (!_conv((t->tm_yday + 7 -
 191                                     (t->tm_wday ? (t->tm_wday - 1) : 6))
 192                                     / 7, 2, '0'))
 193                                         return(0);
 194                                 continue;
 195                         case 'w':
 196                                 if (!_conv(t->tm_wday, 1, '0'))
 197                                         return(0);
 198                                 continue;
 199                         case 'x':
 200                                 if (!_fmt("%m/%d/%y", t))
 201                                         return(0);
 202                                 continue;
 203                         case 'y':
 204                                 if (!_conv((t->tm_year + TM_YEAR_BASE)
 205                                     % 100, 2, '0'))
 206                                         return(0);
 207                                 continue;
 208                         case 'Y':
 209                                 if (!_conv(t->tm_year + TM_YEAR_BASE, 4, '0'))
 210                                         return(0);
 211                                 continue;
 212                         case 'Z':
 213                                 if (!t->tm_zone || !_add(t->tm_zone))
 214                                         return(0);
 215                                 continue;
 216                         case '%':
 217                         /*
 218                          * X311J/88-090 (4.12.3.5): if conversion char is
 219                          * undefined, behavior is undefined.  Print out the
 220                          * character itself as printf(3) does.
 221                          */
 222                         default:
 223                                 break;
 224                 }
 225                 if (!gsize--)
 226                         return(0);
 227                 *pt++ = *format;
 228         }
 229         return(gsize);
 230 }
 231
 232 static
 233 _conv(n, digits, pad)
 234         int n, digits;
 235         char pad;
 236 {
 237         static char buf[10];
 238         register char *p;
 239
 240         for (p = buf + sizeof(buf) - 2; n > 0 && p > buf; n /= 10, --digits)
 241                 *p-- = n % 10 + '0';
 242         while (p > buf && digits-- > 0)
 243                 *p-- = pad;
 244         return(_add(++p));
 245 }
 246
 247 static
 248 _add(str)
 249         register char *str;
 250 {
 251         for (;; ++pt, --gsize) {
 252                 if (!gsize)
 253                         return(0);
 254                 if (!(*pt = *str++))
 255                         return(1);
 256         }
 257 }