pw/psdate.c

   1 /*-
   2  * Copyright (C) 1996
   3  *      David L. Nugent.  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  *
  14  * THIS SOFTWARE IS PROVIDED BY DAVID L. NUGENT AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL DAVID L. NUGENT OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  */
  26
  27 #ifndef lint
  28 static const char rcsid[] =
  29         "$Id$";
  30 #endif /* not lint */
  31
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <string.h>
  35 #include <ctype.h>
  36
  37 #include "psdate.h"
  38
  39
  40 static int
  41 a2i(char const ** str)
  42 {
  43         int             i = 0;
  44         char const     *s = *str;
  45
  46         if (isdigit(*s)) {
  47                 i = atoi(s);
  48                 while (isdigit(*s))
  49                         ++s;
  50                 *str = s;
  51         }
  52         return i;
  53 }
  54
  55 static int
  56 numerics(char const * str)
  57 {
  58         int             rc = isdigit(*str);
  59
  60         if (rc)
  61                 while (isdigit(*str) || *str == 'x')
  62                         ++str;
  63         return rc && !*str;
  64 }
  65
  66 static int
  67 aindex(char const * arr[], char const ** str, int len)
  68 {
  69         int             l, i;
  70         char            mystr[32];
  71
  72         mystr[len] = '\0';
  73         l = strlen(strncpy(mystr, *str, len));
  74         for (i = 0; i < l; i++)
  75                 mystr[i] = (char) tolower(mystr[i]);
  76         for (i = 0; arr[i] && strcmp(mystr, arr[i]) != 0; i++);
  77         if (arr[i] == NULL)
  78                 i = -1;
  79         else {                  /* Skip past it */
  80                 while (**str && isalpha(**str))
  81                         ++(*str);
  82                 /* And any following whitespace */
  83                 while (**str && (**str == ',' || isspace(**str)))
  84                         ++(*str);
  85         }                       /* Return index */
  86         return i;
  87 }
  88
  89 static int
  90 weekday(char const ** str)
  91 {
  92         static char const *days[] =
  93         {"sun", "mon", "tue", "wed", "thu", "fri", "sat", NULL};
  94
  95         return aindex(days, str, 3);
  96 }
  97
  98 static int
  99 month(char const ** str)
 100 {
 101         static char const *months[] =
 102         {"jan", "feb", "mar", "apr", "may", "jun", "jul",
 103         "aug", "sep", "oct", "nov", "dec", NULL};
 104
 105         return aindex(months, str, 3);
 106 }
 107
 108 static void
 109 parse_time(char const * str, int *hour, int *min, int *sec)
 110 {
 111         *hour = a2i(&str);
 112         if ((str = strchr(str, ':')) == NULL)
 113                 *min = *sec = 0;
 114         else {
 115                 ++str;
 116                 *min = a2i(&str);
 117                 *sec = ((str = strchr(str, ':')) == NULL) ? 0 : atoi(++str);
 118         }
 119 }
 120
 121
 122 static void
 123 parse_datesub(char const * str, int *day, int *mon, int *year)
 124 {
 125         int             i;
 126
 127         static char const nchrs[] = "0123456789 \t,/-.";
 128
 129         if ((i = month(&str)) != -1) {
 130                 *mon = i;
 131                 if ((i = a2i(&str)) != 0)
 132                         *day = i;
 133         } else if ((i = a2i(&str)) != 0) {
 134                 *day = i;
 135                 while (*str && strchr(nchrs + 10, *str) != NULL)
 136                         ++str;
 137                 if ((i = month(&str)) != -1)
 138                         *mon = i;
 139                 else if ((i = a2i(&str)) != 0)
 140                         *mon = i - 1;
 141         } else
 142                 return;
 143
 144         while (*str && strchr(nchrs + 10, *str) != NULL)
 145                 ++str;
 146         if (isdigit(*str)) {
 147                 *year = atoi(str);
 148                 if (*year > 1900)
 149                         *year -= 1900;
 150                 else if (*year < 32)
 151                         *year += 100;
 152         }
 153 }
 154
 155
 156 /*-
 157  * Parse time must be flexible, it handles the following formats:
 158  * nnnnnnnnnnn          UNIX timestamp (all numeric), 0 = now
 159  * 0xnnnnnnnn           UNIX timestamp in hexadecimal
 160  * 0nnnnnnnnn           UNIX timestamp in octal
 161  * 0                    Given time
 162  * +nnnn[smhdwoy]       Given time + nnnn hours, mins, days, weeks, months or years
 163  * -nnnn[smhdwoy]       Given time - nnnn hours, mins, days, weeks, months or years
 164  * dd[ ./-]mmm[ ./-]yy  Date }
 165  * hh:mm:ss             Time } May be combined
 166  */
 167
 168 time_t
 169 parse_date(time_t dt, char const * str)
 170 {
 171         char           *p;
 172         int             i;
 173         long            val;
 174         struct tm      *T;
 175
 176         if (dt == 0)
 177                 dt = time(NULL);
 178
 179         while (*str && isspace(*str))
 180                 ++str;
 181
 182         if (numerics(str)) {
 183                 val = strtol(str, &p, 0);
 184                 dt = val ? val : dt;
 185         } else if (*str == '+' || *str == '-') {
 186                 val = strtol(str, &p, 0);
 187                 switch (*p) {
 188                 case 'h':
 189                 case 'H':       /* hours */
 190                         dt += (val * 3600L);
 191                         break;
 192                 case '\0':
 193                 case 'm':
 194                 case 'M':       /* minutes */
 195                         dt += (val * 60L);
 196                         break;
 197                 case 's':
 198                 case 'S':       /* seconds */
 199                         dt += val;
 200                         break;
 201                 case 'd':
 202                 case 'D':       /* days */
 203                         dt += (val * 86400L);
 204                         break;
 205                 case 'w':
 206                 case 'W':       /* weeks */
 207                         dt += (val * 604800L);
 208                         break;
 209                 case 'o':
 210                 case 'O':       /* months */
 211                         T = localtime(&dt);
 212                         T->tm_mon += (int) val;
 213                         i = T->tm_mday;
 214                         goto fixday;
 215                 case 'y':
 216                 case 'Y':       /* years */
 217                         T = localtime(&dt);
 218                         T->tm_year += (int) val;
 219                         i = T->tm_mday;
 220         fixday:
 221                         dt = mktime(T);
 222                         T = localtime(&dt);
 223                         if (T->tm_mday != i) {
 224                                 T->tm_mday = 1;
 225                                 dt = mktime(T);
 226                                 dt -= (time_t) 86400L;
 227                         }
 228                 default:        /* unknown */
 229                         break;  /* leave untouched */
 230                 }
 231         } else {
 232                 char           *q, tmp[64];
 233
 234                 /*
 235                  * Skip past any weekday prefix
 236                  */
 237                 weekday(&str);
 238                 str = strncpy(tmp, str, sizeof tmp - 1);
 239                 tmp[sizeof tmp - 1] = '\0';
 240                 T = localtime(&dt);
 241
 242                 /*
 243                  * See if we can break off any timezone
 244                  */
 245                 while ((q = strrchr(tmp, ' ')) != NULL) {
 246                         if (strchr("(+-", q[1]) != NULL)
 247                                 *q = '\0';
 248                         else {
 249                                 int             j = 1;
 250
 251                                 while (q[j] && isupper(q[j]))
 252                                         ++j;
 253                                 if (q[j] == '\0')
 254                                         *q = '\0';
 255                                 else
 256                                         break;
 257                         }
 258                 }
 259
 260                 /*
 261                  * See if there is a time hh:mm[:ss]
 262                  */
 263                 if ((p = strchr(tmp, ':')) == NULL) {
 264
 265                         /*
 266                          * No time string involved
 267                          */
 268                         T->tm_hour = T->tm_min = T->tm_sec = 0;
 269                         parse_datesub(tmp, &T->tm_mday, &T->tm_mon, &T->tm_year);
 270                 } else {
 271                         char            datestr[64], timestr[64];
 272
 273                         /*
 274                          * Let's chip off the time string
 275                          */
 276                         if ((q = strpbrk(p, " \t")) != NULL) {  /* Time first? */
 277                                 int             l = q - str;
 278
 279                                 strncpy(timestr, str, l);
 280                                 timestr[l] = '\0';
 281                                 strncpy(datestr, q + 1, sizeof datestr);
 282                                 datestr[sizeof datestr - 1] = '\0';
 283                                 parse_time(timestr, &T->tm_hour, &T->tm_min, &T->tm_sec);
 284                                 parse_datesub(datestr, &T->tm_mday, &T->tm_mon, &T->tm_year);
 285                         } else if ((q = strrchr(tmp, ' ')) != NULL) {   /* Time last */
 286                                 int             l = q - tmp;
 287
 288                                 strncpy(timestr, q + 1, sizeof timestr);
 289                                 timestr[sizeof timestr - 1] = '\0';
 290                                 strncpy(datestr, tmp, l);
 291                                 datestr[l] = '\0';
 292                         } else  /* Bail out */
 293                                 return dt;
 294                         parse_time(timestr, &T->tm_hour, &T->tm_min, &T->tm_sec);
 295                         parse_datesub(datestr, &T->tm_mday, &T->tm_mon, &T->tm_year);
 296                 }
 297                 dt = mktime(T);
 298         }
 299         return dt;
 300 }