string.subproj/strftime.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1989, 1993
  24  *      The Regents of the University of California.  All rights reserved.
  25  *
  26  * Redistribution and use in source and binary forms, with or without
  27  * modification, are permitted provided that the following conditions
  28  * are met:
  29  * 1. Redistributions of source code must retain the above copyright
  30  *    notice, this list of conditions and the following disclaimer.
  31  * 2. Redistributions in binary form must reproduce the above copyright
  32  *    notice, this list of conditions and the following disclaimer in the
  33  *    documentation and/or other materials provided with the distribution.
  34  * 3. All advertising materials mentioning features or use of this software
  35  *    must display the following acknowledgement:
  36  *      This product includes software developed by the University of
  37  *      California, Berkeley and its contributors.
  38  * 4. Neither the name of the University nor the names of its contributors
  39  *    may be used to endorse or promote products derived from this software
  40  *    without specific prior written permission.
  41  *
  42  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  43  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  44  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  45  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  46  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  47  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  48  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  49  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  50  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  51  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  52  * SUCH DAMAGE.
  53  */
  54
  55
  56 #include <sys/types.h>
  57 #include <sys/time.h>
  58 #include <tzfile.h>
  59 #include <string.h>
  60
  61 static char *afmt[] = {
  62         "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat",
  63 };
  64 static char *Afmt[] = {
  65         "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday",
  66         "Saturday",
  67 };
  68 static char *bfmt[] = {
  69         "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep",
  70         "Oct", "Nov", "Dec",
  71 };
  72 static char *Bfmt[] = {
  73         "January", "February", "March", "April", "May", "June", "July",
  74         "August", "September", "October", "November", "December",
  75 };
  76
  77 static size_t gsize;
  78 static char *pt;
  79 static int _add __P((char *));
  80 static int _conv __P((int, int, int));
  81 static int _secs __P((const struct tm *));
  82 static size_t _fmt __P((const char *, const struct tm *));
  83
  84 size_t
  85 strftime(s, maxsize, format, t)
  86         char *s;
  87         size_t maxsize;
  88         const char *format;
  89         const struct tm *t;
  90 {
  91
  92         pt = s;
  93         if ((gsize = maxsize) < 1)
  94                 return(0);
  95         if (_fmt(format, t)) {
  96                 *pt = '\0';
  97                 return(maxsize - gsize);
  98         }
  99         return(0);
 100 }
 101
 102 static size_t
 103 _fmt(format, t)
 104         register const char *format;
 105         const struct tm *t;
 106 {
 107         for (; *format; ++format) {
 108                 if (*format == '%')
 109                         switch(*++format) {
 110                         case '\0':
 111                                 --format;
 112                                 break;
 113                         case 'A':
 114                                 if (t->tm_wday < 0 || t->tm_wday > 6)
 115                                         return(0);
 116                                 if (!_add(Afmt[t->tm_wday]))
 117                                         return(0);
 118                                 continue;
 119                         case 'a':
 120                                 if (t->tm_wday < 0 || t->tm_wday > 6)
 121                                         return(0);
 122                                 if (!_add(afmt[t->tm_wday]))
 123                                         return(0);
 124                                 continue;
 125                         case 'B':
 126                                 if (t->tm_mon < 0 || t->tm_mon > 11)
 127                                         return(0);
 128                                 if (!_add(Bfmt[t->tm_mon]))
 129                                         return(0);
 130                                 continue;
 131                         case 'b':
 132                         case 'h':
 133                                 if (t->tm_mon < 0 || t->tm_mon > 11)
 134                                         return(0);
 135                                 if (!_add(bfmt[t->tm_mon]))
 136                                         return(0);
 137                                 continue;
 138                         case 'C':
 139                                 if (!_fmt("%a %b %e %H:%M:%S %Y", t))
 140                                         return(0);
 141                                 continue;
 142                         case 'c':
 143                                 if (!_fmt("%m/%d/%y %H:%M:%S", t))
 144                                         return(0);
 145                                 continue;
 146                         case 'D':
 147                                 if (!_fmt("%m/%d/%y", t))
 148                                         return(0);
 149                                 continue;
 150                         case 'd':
 151                                 if (!_conv(t->tm_mday, 2, '0'))
 152                                         return(0);
 153                                 continue;
 154                         case 'e':
 155                                 if (!_conv(t->tm_mday, 2, ' '))
 156                                         return(0);
 157                                 continue;
 158                         case 'H':
 159                                 if (!_conv(t->tm_hour, 2, '0'))
 160                                         return(0);
 161                                 continue;
 162                         case 'I':
 163                                 if (!_conv(t->tm_hour % 12 ?
 164                                     t->tm_hour % 12 : 12, 2, '0'))
 165                                         return(0);
 166                                 continue;
 167                         case 'j':
 168                                 if (!_conv(t->tm_yday + 1, 3, '0'))
 169                                         return(0);
 170                                 continue;
 171                         case 'k':
 172                                 if (!_conv(t->tm_hour, 2, ' '))
 173                                         return(0);
 174                                 continue;
 175                         case 'l':
 176                                 if (!_conv(t->tm_hour % 12 ?
 177                                     t->tm_hour % 12 : 12, 2, ' '))
 178                                         return(0);
 179                                 continue;
 180                         case 'M':
 181                                 if (!_conv(t->tm_min, 2, '0'))
 182                                         return(0);
 183                                 continue;
 184                         case 'm':
 185                                 if (!_conv(t->tm_mon + 1, 2, '0'))
 186                                         return(0);
 187                                 continue;
 188                         case 'n':
 189                                 if (!_add("\n"))
 190                                         return(0);
 191                                 continue;
 192                         case 'p':
 193                                 if (!_add(t->tm_hour >= 12 ? "PM" : "AM"))
 194                                         return(0);
 195                                 continue;
 196                         case 'R':
 197                                 if (!_fmt("%H:%M", t))
 198                                         return(0);
 199                                 continue;
 200                         case 'r':
 201                                 if (!_fmt("%I:%M:%S %p", t))
 202                                         return(0);
 203                                 continue;
 204                         case 'S':
 205                                 if (!_conv(t->tm_sec, 2, '0'))
 206                                         return(0);
 207                                 continue;
 208                         case 's':
 209                                 if (!_secs(t))
 210                                         return(0);
 211                                 continue;
 212                         case 'T':
 213                         case 'X':
 214                                 if (!_fmt("%H:%M:%S", t))
 215                                         return(0);
 216                                 continue;
 217                         case 't':
 218                                 if (!_add("\t"))
 219                                         return(0);
 220                                 continue;
 221                         case 'U':
 222                                 if (!_conv((t->tm_yday + 7 - t->tm_wday) / 7,
 223                                     2, '0'))
 224                                         return(0);
 225                                 continue;
 226                         case 'W':
 227                                 if (!_conv((t->tm_yday + 7 -
 228                                     (t->tm_wday ? (t->tm_wday - 1) : 6))
 229                                     / 7, 2, '0'))
 230                                         return(0);
 231                                 continue;
 232                         case 'w':
 233                                 if (!_conv(t->tm_wday, 1, '0'))
 234                                         return(0);
 235                                 continue;
 236                         case 'x':
 237                                 if (!_fmt("%m/%d/%y", t))
 238                                         return(0);
 239                                 continue;
 240                         case 'y':
 241                                 if (!_conv((t->tm_year + TM_YEAR_BASE)
 242                                     % 100, 2, '0'))
 243                                         return(0);
 244                                 continue;
 245                         case 'Y':
 246                                 if (!_conv(t->tm_year + TM_YEAR_BASE, 4, '0'))
 247                                         return(0);
 248                                 continue;
 249                         case 'Z':
 250                                 if (!t->tm_zone || !_add(t->tm_zone))
 251                                         return(0);
 252                                 continue;
 253                         case '%':
 254                         /*
 255                          * X311J/88-090 (4.12.3.5): if conversion char is
 256                          * undefined, behavior is undefined.  Print out the
 257                          * character itself as printf(3) does.
 258                          */
 259                         default:
 260                                 break;
 261                 }
 262                 if (!gsize--)
 263                         return(0);
 264                 *pt++ = *format;
 265         }
 266         return(gsize);
 267 }
 268
 269 static int
 270 _secs(t)
 271         const struct tm *t;
 272 {
 273         static char buf[15];
 274         register time_t s;
 275         register char *p;
 276         struct tm tmp;
 277
 278         /* Make a copy, mktime(3) modifies the tm struct. */
 279         tmp = *t;
 280         s = mktime(&tmp);
 281         for (p = buf + sizeof(buf) - 2; s > 0 && p > buf; s /= 10)
 282                 *p-- = s % 10 + '0';
 283         return(_add(++p));
 284 }
 285
 286 static int
 287 _conv(n, digits, pad)
 288         int n, digits, pad;
 289 {
 290         static char buf[10];
 291         register char *p;
 292
 293         for (p = buf + sizeof(buf) - 2; n > 0 && p > buf; n /= 10, --digits)
 294                 *p-- = n % 10 + '0';
 295         while (p > buf && digits-- > 0)
 296                 *p-- = pad;
 297         return(_add(++p));
 298 }
 299
 300 static int
 301 _add(str)
 302         register char *str;
 303 {
 304         for (;; ++pt, --gsize) {
 305                 if (!gsize)
 306                         return(0);
 307                 if (!(*pt = *str++))
 308                         return(1);
 309         }
 310 }