cal: replace magic constants with symbolical values

This makes it easier to know what the values in guestion represent.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

diff --git a/misc-utils/cal.c b/misc-utils/cal.c
index 98ce431357494a17375d45a0033f3adbcdb491e9..dd26532b6778bfc4239932e484cb9641ec9b0ae2 100644 (file)
--- a/misc-utils/cal.c
+++ b/misc-utils/cal.c
@@ -171,15 +171,27 @@ enum {
        NONEDAY
 };
 
-#define        FIRST_WEEKDAY           SATURDAY        /* Jan 1st, 1 was a Saturday */
+enum {
+       JANUARY = 1,
+       FEBRUARY,
+       MARCH,
+       APRIL,
+       MAY,
+       JUNE,
+       JULY,
+       AUGUST,
+       SEPTEMBER,
+       OCTOBER,
+       NOVEMBER,
+       DECEMBER
+};
+
 #define REFORMATION_YEAR       1752            /* Signed-off-by: Lord Chesterfield */
-#define REFORMATION_MONTH      9               /* September */
-#define        FIRST_MISSING_DAY       639799          /* 3 Sep 1752 */
+#define REFORMATION_MONTH      SEPTEMBER
 #define        NUMBER_MISSING_DAYS     11              /* 11 day correction */
 #define YDAY_AFTER_MISSING     258             /* 14th in Sep 1752 */
 
-#define DAYS_IN_YEAR           365             /* the common case, leap years are calculated */
-#define MONTHS_IN_YEAR         12
+#define MONTHS_IN_YEAR         DECEMBER
 #define DAYS_IN_MONTH          31
 #define        MAXDAYS                 42              /* slots in a month array */
 #define        SPACE                   -1              /* used in day array */
@@ -188,12 +200,9 @@ enum {
 
 #define        DAY_LEN                 3               /* 3 spaces per day */
 #define        WEEK_LEN                (DAYS_IN_WEEK * DAY_LEN)
-#define        HEAD_SEP                2
 #define MONTHS_IN_YEAR_ROW     3               /* month columns in year view */
 #define WNUM_LEN                3
 
-#define TODAY_FLAG             0x400           /* flag day for highlighting */
-
 #define FMT_ST_CHARS 300       /* 90 suffices in most locales */
 
 static const int days_in_month[2][13] = {
@@ -473,15 +482,15 @@ int main(int argc, char **argv)
                        errx(EXIT_FAILURE, _("illegal week value: year %d "
                                             "doesn't have week %d"),
                                        ctl.req.year, ctl.req.week);
-               while (m <= 12 && yday > days_in_month[leap][m])
+               while (m <= DECEMBER && yday > days_in_month[leap][m])
                        yday -= days_in_month[leap][m++];
-               if (m > 12) {
+               if (m > DECEMBER) {
                        /* In some years (e.g. 2010 in ISO mode) it's possible
                         * to have a remnant of week 53 starting the year yet
                         * the year in question ends during 52, in this case
                         * we're assuming that early remnant is being referred
                         * to if 53 is given as argument. */
-                       if (ctl.req.week != week_number(31, 12, ctl.req.year - 1, &ctl))
+                       if (ctl.req.week != week_number(31, DECEMBER, ctl.req.year - 1, &ctl))
                                errx(EXIT_FAILURE,
                                        _("illegal week value: year %d "
                                          "doesn't have week %d"),
@@ -589,7 +598,7 @@ static void cal_fill_month(struct cal_month *month, const struct cal_control *ct
                        continue;
                }
                if (j < month_days) {
-                       if (month->year == 1752 && month->month == 9 && (j == 3 || j == 247))
+                       if (month->year == REFORMATION_YEAR && month->month == REFORMATION_MONTH && (j == 3 || j == 247))
                                j += NUMBER_MISSING_DAYS;
                        month->days[i] = j;
                        j++;
@@ -817,21 +826,21 @@ static int day_in_week(int day, int month, int32_t year)
                FRIDAY, MONDAY, SUNDAY, WEDNESDAY, FRIDAY, MONDAY,
                WEDNESDAY, SATURDAY, TUESDAY, THURSDAY, SUNDAY, TUESDAY
        };
-       if (year != 1753)
-               year -= month < 3;
+       if (year != REFORMATION_YEAR + 1)
+               year -= month < MARCH;
        else
-               year -= (month < 3) + 14;
+               year -= (month < MARCH) + 14;
        if (REFORMATION_YEAR < year
-           || (year == REFORMATION_YEAR && 9 < month)
-           || (year == REFORMATION_YEAR && month == 9 && 13 < day)) {
+           || (year == REFORMATION_YEAR && REFORMATION_MONTH < month)
+           || (year == REFORMATION_YEAR && month == REFORMATION_MONTH && 13 < day)) {
                int64_t long_year = year;
                return (long_year + (year / 4) - (year / 100) + (year / 400) + reform[month - 1] +
-                       day) % 7;
+                       day) % DAYS_IN_WEEK;
        }
        if (year < REFORMATION_YEAR
-           || (year == REFORMATION_YEAR && month < 9)
-           || (year == REFORMATION_YEAR && month == 9 && day < 3))
-               return (year + year / 4 + old[month - 1] + day) % 7;
+           || (year == REFORMATION_YEAR && month < REFORMATION_MONTH)
+           || (year == REFORMATION_YEAR && month == REFORMATION_MONTH && day < 3))
+               return (year + year / 4 + old[month - 1] + day) % DAYS_IN_WEEK;
        return NONEDAY;
 }
 
@@ -845,7 +854,7 @@ static int day_in_week(int day, int month, int32_t year)
 static int week_number(int day, int month, int32_t year, const struct cal_control *ctl)
 {
        int fday = 0, yday;
-       const int wday = day_in_week(1, 1, year);
+       const int wday = day_in_week(1, JANUARY, year);
 
        if (ctl->weektype & WEEK_NUM_ISO)
                fday = wday + (wday >= FRIDAY ? -2 : 5);
@@ -858,8 +867,8 @@ static int week_number(int day, int month, int32_t year, const struct cal_contro
        /* For julian dates the month can be set to 1, the global julian
         * variable cannot be relied upon here, because we may recurse
         * internally for 31.12. which would not work. */
-       if (day > 31)
-               month = 1;
+       if (day > DAYS_IN_MONTH)
+               month = JANUARY;
 
        yday = day_in_year(day,month,year);
        if (year == REFORMATION_YEAR) {
@@ -868,8 +877,8 @@ static int week_number(int day, int month, int32_t year, const struct cal_contro
        }
 
        /* Last year is last year */
-       if (yday + fday < 7)
-               return week_number(31, 12, year - 1, ctl);
+       if (yday + fday < DAYS_IN_WEEK)
+               return week_number(31, DECEMBER, year - 1, ctl);
 
        /* Or it could be part of the next year.  The reformation year had less
         * days than 365 making this check invalid, but reformation year ended
@@ -877,11 +886,11 @@ static int week_number(int day, int month, int32_t year, const struct cal_contro
        if (ctl->weektype == WEEK_NUM_ISO && yday >= 363
            && day_in_week(day, month, year) >= MONDAY
            && day_in_week(day, month, year) <= WEDNESDAY
-           && day_in_week(31, 12, year) >= MONDAY
-           && day_in_week(31, 12, year) <= WEDNESDAY)
-               return week_number(1, 1, year + 1, ctl);
+           && day_in_week(31, DECEMBER, year) >= MONDAY
+           && day_in_week(31, DECEMBER, year) <= WEDNESDAY)
+               return week_number(1, JANUARY, year + 1, ctl);
 
-       return (yday + fday) / 7;
+       return (yday + fday) / DAYS_IN_WEEK;
 }
 
 /*
@@ -895,8 +904,8 @@ static int week_to_day(const struct cal_control *ctl)
 {
        int yday, wday;
 
-       wday = day_in_week(1, 1, ctl->req.year);
-       yday = ctl->req.week * 7 - wday;
+       wday = day_in_week(1, JANUARY, ctl->req.year);
+       yday = ctl->req.week * DAYS_IN_WEEK - wday;
 
        if (ctl->weektype & WEEK_NUM_ISO)
                yday -= (wday >= FRIDAY ? -2 : 5);