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root/usr/lib/libc/time/strftime.c

DEFINITIONS

1. strftime
2. _fmt
3. _secs
4. _conv
5. _add

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