git.marmaro.de Git - mmh/blob - docs/historical/mh-6.8.5/miscellany/mem/RCS/promptdate.c,v

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   8 1.2
   9 date    96.02.09.17.38.07;      author jromine; state Exp;
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  13 1.1
  14 date    96.02.09.17.32.07;      author jromine; state Exp;
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  19 desc
  20 @@
  21
  22
  23 1.2
  24 log
  25 @avoid use of gets()
  26 @
  27 text
  28 @#ifndef        lint
  29 static char Id[] = "$Id:$";
  30 #endif
  31
  32 #include        <stdio.h>
  33 #include        <sys/time.h>
  34 #include        <ctype.h>
  35
  36 /*
  37 **      promptdate
  38 **      prompt user for a date specification which can be quite minimal
  39 **      and print it in a form suitable for parsing by MH
  40 */
  41
  42 #define         MAXLINE         128
  43
  44 char            *mname[12]      ={
  45                 "Jan","Feb","Mar","Apr","May","Jun",
  46                 "Jul","Aug","Sep","Oct","Nov","Dec"};
  47 char            *dname[7]       ={
  48                 "Sun","Mon","Tue","Wed","Thu","Fri","Sat"};
  49 struct tm       now;
  50 int             dayspast        = 0;
  51 int             monthlen[2][12] ={
  52                 31,28,31,30,31,30,31,31,30,31,30,31,
  53                 31,29,31,30,31,30,31,31,30,31,30,31};
  54 char            *defaultformat  = "%d %N %y 00:00";
  55
  56 main(argc, argv)
  57         int             argc;
  58         char            **argv;
  59 {
  60         register int    c;
  61         struct tm       then;
  62         extern int      optind;         /* defined in getopt */
  63         extern char     *optarg;        /* defined in getopt */
  64         int             getopt();
  65         long            secsfr70();
  66
  67         while ((c = getopt (argc, argv, "f:")) != EOF)
  68         {
  69                 switch (c)
  70                 {
  71                 case 'f':
  72                         defaultformat = optarg;
  73                         break;
  74                 default:
  75                         fprintf(stderr, "usage: %s [-f format] [datespec]\n", argv[0]);
  76                         exit (1);
  77                 }
  78         }
  79         argc -= optind;
  80         argv += optind;
  81
  82         finddate(&now, dayspast = (int)(secsfr70()/86400L));
  83
  84         if (argc <= 0)                  /* get from user */
  85         {
  86                 if (!promptdate(&then))
  87                         exit(1);
  88                 printdate(&then, defaultformat);
  89         }
  90         else                            /* get from command line */
  91         {
  92                 if (!decodedate(argv[0], &then))
  93                         exit(1);
  94                 printdate(&then, defaultformat);
  95         }
  96         exit(0);
  97 }
  98
  99 int promptdate(when)
 100         struct tm       *when;
 101 {
 102         char            line[MAXLINE];
 103         int             decodedate();
 104         char            *p;
 105
 106         for (;;)
 107         {
 108                 fprintf(stderr, "When? ");
 109                 if (fgets(line, sizeof(line), stdin) == NULL)
 110                 {
 111                         fprintf(stderr, "\n");
 112                         return (0);
 113                 }
 114                 p = line + strlen (line) - 1;
 115                 if (*p == '\n')
 116                         *p = '\0';
 117                 if (decodedate(line, when))
 118                         return (1);
 119         }
 120 /*NOTREACHED*/
 121 }
 122
 123 int decodedate(line, when)
 124         char            *line;
 125         struct tm       *when;
 126 /*
 127 **      accept spec for date in several forms
 128 **      legal are: sun,mon,tue,wed,thu,fri,sat,today,tomorrow,
 129 **      <date><month>,+<relative number of days>
 130 **      <month> should be alpha
 131 **      upper case accepted too
 132 */
 133 {
 134         char            s[4];
 135         register int    i,targetdate;
 136         int             tem;
 137         register char   *lptr;
 138
 139         when->tm_year = now.tm_year;
 140         when->tm_mon = now.tm_mon;
 141         targetdate = dayspast;
 142         for (lptr = line; isspace(*lptr); lptr++)
 143                 ;
 144         if (isdigit(*lptr))
 145         {
 146                 i = sscanf(lptr, "%d%3s%d", &when->tm_mday, s, &tem);
 147                 switch(i)
 148                 {
 149                     case 3:
 150                         when->tm_year = tem;
 151                     case 2:
 152                         fold(s);
 153                         when->tm_mon = monthofyear(s);
 154                         if (i == 3)
 155                                 break;
 156                         if (when->tm_mday != 0 && when->tm_mon != 0 && daysfr70(when) < dayspast)
 157                                 when->tm_year++;
 158                         break;
 159                     case 1:
 160                         if (when->tm_mday != 0 && when->tm_mday < now.tm_mday)
 161                         {
 162                                 if (++when->tm_mon > 12)
 163                                 {
 164                                         when->tm_mon = 1;
 165                                         when->tm_year++;
 166                                 }
 167                         }
 168                 }
 169                 return (validate(when));
 170         }
 171         if (isalpha(*lptr))
 172         {
 173                 sscanf(lptr, "%3s", s);
 174                 fold(s);
 175                 if ((tem = dayofweek(s)) >= 0)
 176                         targetdate += (tem -= now.tm_wday) <= 0 ? tem + 7 : tem;
 177                 else if (strcmp(s, "Tom") == 0)
 178                         targetdate++;
 179                 else if (strcmp(s, "Tod") == 0)
 180                         ;
 181                 else    /* mistake */
 182                         return (0);
 183         }
 184         else if (*lptr == '+')
 185         {
 186                 if (sscanf(++lptr, "%d", &tem) == 0 || tem < 0) /* mistake */
 187                         return (0);
 188                 targetdate += tem;
 189         }
 190         else    /* mistake by default */
 191                 return (0);
 192         finddate(when, targetdate);
 193         return (when->tm_mday != 0);
 194 }
 195
 196 int validate(datetm)
 197 /*
 198 **      check that a given date and month combination is legal
 199 **      datetm->tm_year must hold the year in question
 200 */
 201         register struct tm      *datetm;
 202 {
 203
 204         return (datetm->tm_mday <= monthlen[leapyear(datetm->tm_year)]
 205                 [datetm->tm_mon] && datetm->tm_mday > 0);
 206 }
 207
 208 finddate(datetm, df70)
 209 /*
 210 **      convert days from 1 jan 1970 to a date in struct datetm
 211 */
 212         register int            df70;
 213         register struct tm      *datetm;
 214 {
 215         register struct tm      *tdtm;
 216         long                    longtime;
 217         struct tm               *gmtime();
 218
 219         longtime = df70 * 86400L;
 220         tdtm = gmtime(&longtime);
 221         datetm->tm_yday = tdtm->tm_yday;
 222         datetm->tm_wday = tdtm->tm_wday;
 223         datetm->tm_year = tdtm->tm_year + 1900;
 224         datetm->tm_mon = tdtm->tm_mon;
 225         datetm->tm_mday = tdtm->tm_mday;
 226         datetm->tm_hour = tdtm->tm_hour;
 227         datetm->tm_min = tdtm->tm_min;
 228         datetm->tm_sec = tdtm->tm_sec;
 229 }
 230
 231 fold(s)
 232 /*
 233 **      convert first character to uppercase
 234 **      convert rest of string from uppercase to lower case
 235 */
 236         register char   *s;
 237 {
 238         register char   c;
 239
 240         if ((c = *s) != '\0')
 241                 *s++ += islower(c) ? 'A' - 'a' : 0;
 242         while ((c = *s) != '\0')
 243                 *s++ += isupper(c) ? 'a' - 'A' : 0;
 244 }
 245
 246 int leapyear(y)
 247 /*
 248 **      returns 1 if leapyear 0 otherwise
 249 */
 250         register int    y;
 251 {
 252
 253         return (((y % 4) == 0 && (y % 100) != 0) || (y % 400) == 0);
 254 }
 255
 256 int daysfr70(datetm)
 257 /*
 258 **      returns the number of days from 1 Jan 1970
 259 **      no checking for illegal date at all
 260 */
 261         register struct tm      *datetm;
 262 {
 263         register int            i, totdays;
 264
 265
 266         totdays = 0;
 267         for (i = 1970; i <= 2050 && i < datetm->tm_year; i++)   /* prevent overflow */
 268                 totdays += 365 + leapyear(i);
 269         for (i = 0; i < 12 && i < datetm->tm_mon; i++)
 270                 totdays += monthlen[leapyear(datetm->tm_year)][i];
 271         totdays += datetm->tm_mday - 1;
 272         return (totdays);
 273 }
 274
 275 int monthofyear(s)
 276 /*
 277 **      returns month of year in numeric form when given
 278 **      the first three letters
 279 */
 280         register char   *s;
 281 {
 282         register int    i;
 283
 284         fold(s);
 285         for (i = 12; i-- && strcmp(s,mname[i]); )
 286                 ;
 287         return (i);
 288 }
 289
 290 int dayofweek(s)
 291 /*
 292 **      sunday = 0,...,saturday = 6, nomatch = -1
 293 */
 294         register char   *s;
 295 {
 296         register int    i;
 297
 298         fold(s);
 299         for (i = 7; i-- && strcmp(s,dname[i]); )
 300                 ;
 301         return (i);
 302 }
 303
 304 printdate(date, format)
 305 /*
 306 **      print date in MH acceptable format
 307 **      kludge - general formats are not implemented
 308 */
 309         struct tm       *date;
 310         char            *format;
 311 {
 312         printf("%d %s %d 00:00\n",
 313                 date->tm_mday, mname[date->tm_mon], date->tm_year);
 314 }
 315
 316 long secsfr70()
 317 /*
 318 **      This is system dependent
 319 */
 320 {
 321         register int            dst;
 322         struct timeval          tv;
 323         struct timezone         tz;
 324         struct tm               *localtime();
 325
 326         gettimeofday(&tv, &tz);
 327         dst = localtime(&tv.tv_sec)->tm_isdst;
 328         return (tv.tv_sec - tz.tz_minuteswest * 60 + (dst ? 3600 : 0));
 329 }
 330 @
 331
 332
 333 1.1
 334 log
 335 @Initial revision
 336 @
 337 text
 338 @d1 4
 339 d77 1
 340 a77 1
 341         char            *gets();
 342 d82 1
 343 a82 1
 344                 if (gets(line) == NULL)
 345 d87 3
 346 @