strftime.c revision 1.1
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, 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. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #if defined(LIBC_SCCS) && !defined(lint) 35 /*static char *sccsid = "from: @(#)strftime.c 5.11 (Berkeley) 2/24/91";*/ 36 static char *rcsid = "$Id: strftime.c,v 1.1 1997/04/23 01:18:05 mrg Exp $"; 37 #endif /* LIBC_SCCS and not lint */ 38 39 #include <sys/localedef.h> 40 #include <locale.h> 41 #include <string.h> 42 #include <tzfile.h> 43 #include <time.h> 44 45 static size_t gsize; 46 static char *pt; 47 static int _add(), _conv(), _secs(); 48 static size_t _fmt(); 49 50 size_t 51 strftime(s, maxsize, format, t) 52 char *s; 53 size_t maxsize; 54 const char *format; 55 const struct tm *t; 56 { 57 tzset(); 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 #define SUN_WEEK(t) (((t)->tm_yday + 7 - \ 70 ((t)->tm_wday)) / 7) 71 #define MON_WEEK(t) (((t)->tm_yday + 7 - \ 72 ((t)->tm_wday ? (t)->tm_wday - 1 : 6)) / 7) 73 static size_t 74 _fmt(format, t) 75 register const char *format; 76 const struct tm *t; 77 { 78 for (; *format; ++format) { 79 if (*format == '%') { 80 ++format; 81 if (*format == 'E') { 82 /* Alternate Era */ 83 ++format; 84 } else if (*format == 'O') { 85 /* Alternate numeric symbols */ 86 ++format; 87 } 88 switch(*format) { 89 case '\0': 90 --format; 91 break; 92 case 'A': 93 if (t->tm_wday < 0 || t->tm_wday > 6) 94 return(0); 95 if (!_add(_CurrentTimeLocale->day[t->tm_wday])) 96 return(0); 97 continue; 98 case 'a': 99 if (t->tm_wday < 0 || t->tm_wday > 6) 100 return(0); 101 if (!_add(_CurrentTimeLocale->abday[t->tm_wday])) 102 return(0); 103 continue; 104 case 'B': 105 if (t->tm_mon < 0 || t->tm_mon > 11) 106 return(0); 107 if (!_add(_CurrentTimeLocale->mon[t->tm_mon])) 108 return(0); 109 continue; 110 case 'b': 111 case 'h': 112 if (t->tm_mon < 0 || t->tm_mon > 11) 113 return(0); 114 if (!_add(_CurrentTimeLocale->abmon[t->tm_mon])) 115 return(0); 116 continue; 117 case 'C': 118 if (!_conv((t->tm_year + TM_YEAR_BASE) / 100, 119 2, '0')) 120 return(0); 121 continue; 122 case 'c': 123 if (!_fmt(_CurrentTimeLocale->d_t_fmt, t)) 124 return(0); 125 continue; 126 case 'D': 127 if (!_fmt("%m/%d/%y", t)) 128 return(0); 129 continue; 130 case 'd': 131 if (!_conv(t->tm_mday, 2, '0')) 132 return(0); 133 continue; 134 case 'e': 135 if (!_conv(t->tm_mday, 2, ' ')) 136 return(0); 137 continue; 138 case 'H': 139 if (!_conv(t->tm_hour, 2, '0')) 140 return(0); 141 continue; 142 case 'I': 143 if (!_conv(t->tm_hour % 12 ? 144 t->tm_hour % 12 : 12, 2, '0')) 145 return(0); 146 continue; 147 case 'j': 148 if (!_conv(t->tm_yday + 1, 3, '0')) 149 return(0); 150 continue; 151 case 'k': 152 if (!_conv(t->tm_hour, 2, ' ')) 153 return(0); 154 continue; 155 case 'l': 156 if (!_conv(t->tm_hour % 12 ? 157 t->tm_hour % 12: 12, 2, ' ')) 158 return(0); 159 continue; 160 case 'M': 161 if (!_conv(t->tm_min, 2, '0')) 162 return(0); 163 continue; 164 case 'm': 165 if (!_conv(t->tm_mon + 1, 2, '0')) 166 return(0); 167 continue; 168 case 'n': 169 if (!_add("\n")) 170 return(0); 171 continue; 172 case 'p': 173 if (!_add(_CurrentTimeLocale->am_pm[t->tm_hour >= 12])) 174 return(0); 175 continue; 176 case 'R': 177 if (!_fmt("%H:%M", t)) 178 return(0); 179 continue; 180 case 'r': 181 if (!_fmt(_CurrentTimeLocale->t_fmt_ampm, t)) 182 return(0); 183 continue; 184 case 'S': 185 if (!_conv(t->tm_sec, 2, '0')) 186 return(0); 187 continue; 188 case 's': 189 if (!_secs(t)) 190 return(0); 191 continue; 192 case 'T': 193 if (!_fmt("%H:%M:%S", t)) 194 return(0); 195 continue; 196 case 't': 197 if (!_add("\t")) 198 return(0); 199 continue; 200 case 'U': 201 if (!_conv(SUN_WEEK(t), 2, '0')) 202 return(0); 203 continue; 204 case 'u': 205 if (!_conv(t->tm_wday ? t->tm_wday : 7, 1, '0')) 206 return(0); 207 continue; 208 case 'V': 209 { 210 /* ISO 8601 Week Of Year: 211 If the week (Monday - Sunday) containing 212 January 1 has four or more days in the new 213 year, then it is week 1; otherwise it is 214 week 53 of the previous year and the next 215 week is week one. */ 216 217 int week = MON_WEEK(t); 218 219 int days = (((t)->tm_yday + 7 - \ 220 ((t)->tm_wday ? (t)->tm_wday - 1 : 6)) % 7); 221 222 223 if (days >= 4) { 224 week++; 225 } else if (week == 0) { 226 week = 53; 227 } 228 229 if (!_conv(week, 2, '0')) 230 return(0); 231 continue; 232 } 233 case 'W': 234 if (!_conv(MON_WEEK(t), 2, '0')) 235 return(0); 236 continue; 237 case 'w': 238 if (!_conv(t->tm_wday, 1, '0')) 239 return(0); 240 continue; 241 case 'x': 242 if (!_fmt(_CurrentTimeLocale->d_fmt, t)) 243 return(0); 244 continue; 245 case 'X': 246 if (!_fmt(_CurrentTimeLocale->t_fmt, t)) 247 return(0); 248 continue; 249 case 'y': 250 if (!_conv((t->tm_year + TM_YEAR_BASE) % 100, 251 2, '0')) 252 return(0); 253 continue; 254 case 'Y': 255 if (!_conv((t->tm_year + TM_YEAR_BASE), 4, '0')) 256 return(0); 257 continue; 258 case 'Z': 259 if (t->tm_zone && !_add(t->tm_zone)) 260 return(0); 261 continue; 262 case '%': 263 /* 264 * X311J/88-090 (4.12.3.5): if conversion char is 265 * undefined, behavior is undefined. Print out the 266 * character itself as printf(3) does. 267 */ 268 default: 269 break; 270 } 271 } 272 if (!gsize--) 273 return(0); 274 *pt++ = *format; 275 } 276 return(gsize); 277 } 278 279 static int 280 _secs(t) 281 const struct tm *t; 282 { 283 static char buf[15]; 284 register time_t s; 285 register char *p; 286 struct tm tmp; 287 288 /* Make a copy, mktime(3) modifies the tm struct. */ 289 tmp = *t; 290 s = mktime(&tmp); 291 for (p = buf + sizeof(buf) - 2; s > 0 && p > buf; s /= 10) 292 *p-- = s % 10 + '0'; 293 return(_add(++p)); 294 } 295 296 static int 297 _conv(n, digits, pad) 298 int n, digits; 299 char pad; 300 { 301 static char buf[10]; 302 register char *p; 303 304 for (p = buf + sizeof(buf) - 2; n > 0 && p > buf; n /= 10, --digits) 305 *p-- = n % 10 + '0'; 306 while (p > buf && digits-- > 0) 307 *p-- = pad; 308 return(_add(++p)); 309 } 310 311 static int 312 _add(str) 313 register const char *str; 314 { 315 for (;; ++pt, --gsize) { 316 if (!gsize) 317 return(0); 318 if (!(*pt = *str++)) 319 return(1); 320 } 321 } 322
Indexes created Mon Sep 29 21:09:56 GMT 2025