/*
* dtime.c -- time/date routines
*
* $Id: dtime.c,v 1.4 2002/07/02 22:09:14 kenh Exp $
*
* This code is Copyright (c) 2002, by the authors of nmh. See the
* COPYRIGHT file in the root directory of the nmh distribution for
* complete copyright information.
*/
#include <h/mh.h> /* for snprintf() */
#include <h/nmh.h>
#include <h/tws.h>
#if !defined(HAVE_TM_GMTOFF) && !defined(HAVE_TZSET)
# include <sys/timeb.h>
#endif
#ifdef TIME_WITH_SYS_TIME
# include <sys/time.h>
# include <time.h>
#else
# ifdef HAVE_SYS_TIME_H
# include <sys/time.h>
# else
# include <time.h>
# endif
#endif
#if !defined(HAVE_TM_GMTOFF) && defined(HAVE_TZSET)
extern int daylight;
extern long timezone;
extern char *tzname[];
#endif
#ifndef abs
# define abs(a) (a >= 0 ? a : -a)
#endif
/*
* The number of days in the year, accounting for leap years
*/
#define dysize(y) \
(((y) % 4) ? 365 : (((y) % 100) ? 366 : (((y) % 400) ? 365 : 366)))
char *tw_moty[] = {
"Jan", "Feb", "Mar", "Apr",
"May", "Jun", "Jul", "Aug",
"Sep", "Oct", "Nov", "Dec",
NULL
};
char *tw_dotw[] = {
"Sun", "Mon", "Tue",
"Wed", "Thu", "Fri",
"Sat", NULL
};
char *tw_ldotw[] = {
"Sunday", "Monday", "Tuesday",
"Wednesday", "Thursday", "Friday",
"Saturday", NULL
};
struct zone {
char *std;
char *dst;
int shift;
};
static struct zone zones[] = {
{ "GMT", "BST", 0 },
{ "EST", "EDT", -5 },
{ "CST", "CDT", -6 },
{ "MST", "MDT", -7 },
{ "PST", "PDT", -8 },
#if 0
/* RFC1123 specifies do not use military TZs */
{ "A", NULL, -1 },
{ "B", NULL, -2 },
{ "C", NULL, -3 },
{ "D", NULL, -4 },
{ "E", NULL, -5 },
{ "F", NULL, -6 },
{ "G", NULL, -7 },
{ "H", NULL, -8 },
{ "I", NULL, -9 },
{ "K", NULL, -10 },
{ "L", NULL, -11 },
{ "M", NULL, -12 },
{ "N", NULL, 1 },
#ifndef HUJI
{ "O", NULL, 2 },
#else
{ "JST", "JDT", 2 },
#endif
{ "P", NULL, 3 },
{ "Q", NULL, 4 },
{ "R", NULL, 5 },
{ "S", NULL, 6 },
{ "T", NULL, 7 },
{ "U", NULL, 8 },
{ "V", NULL, 9 },
{ "W", NULL, 10 },
{ "X", NULL, 11 },
{ "Y", NULL, 12 },
#endif
{ NULL, NULL, 0 }
};
static int dmsize[] = {
31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
};
/*
* Get current time (adjusted for local time
* zone and daylight savings time) expressed
* as nmh "broken-down" time structure.
*/
struct tws *
dlocaltimenow (void)
{
time_t clock;
time (&clock);
return dlocaltime (&clock);
}
/*
* Take clock value and return pointer to nmh time structure
* containing "broken-down" time. The time is adjusted for
* local time zone and daylight savings time.
*/
struct tws *
dlocaltime (time_t *clock)
{
static struct tws tw;
struct tm *tm;
#if !defined(HAVE_TM_GMTOFF) && !defined(HAVE_TZSET)
struct timeb tb;
#endif
if (!clock)
return NULL;
tm = localtime (clock);
tw.tw_sec = tm->tm_sec;
tw.tw_min = tm->tm_min;
tw.tw_hour = tm->tm_hour;
tw.tw_mday = tm->tm_mday;
tw.tw_mon = tm->tm_mon;
/*
* tm_year is always "year - 1900".
* So we correct for this.
*/
tw.tw_year = tm->tm_year + 1900;
tw.tw_wday = tm->tm_wday;
tw.tw_yday = tm->tm_yday;
tw.tw_flags = TW_NULL;
if (tm->tm_isdst)
tw.tw_flags |= TW_DST;
#ifdef HAVE_TM_GMTOFF
tw.tw_zone = tm->tm_gmtoff / 60;
if (tm->tm_isdst) /* if DST is in effect */
tw.tw_zone -= 60; /* reset to normal offset */
#else
# ifdef HAVE_TZSET
tzset();
tw.tw_zone = -(timezone / 60);
# else
ftime (&tb);
tw.tw_zone = -tb.timezone;
# endif
#endif
tw.tw_flags &= ~TW_SDAY;
tw.tw_flags |= TW_SEXP;
tw.tw_flags &= ~TW_SZONE;
tw.tw_flags |= TW_SZEXP;
tw.tw_clock = *clock;
return (&tw);
}
/*
* Take clock value and return pointer to nmh time
* structure containing "broken-down" time. Time is
* expressed in UTC (Coordinated Universal Time).
*/
struct tws *
dgmtime (time_t *clock)
{
static struct tws tw;
struct tm *tm;
if (!clock)
return NULL;
tm = gmtime (clock);
tw.tw_sec = tm->tm_sec;
tw.tw_min = tm->tm_min;
tw.tw_hour = tm->tm_hour;
tw.tw_mday = tm->tm_mday;
tw.tw_mon = tm->tm_mon;
/*
* tm_year is always "year - 1900"
* So we correct for this.
*/
tw.tw_year = tm->tm_year + 1900;
tw.tw_wday = tm->tm_wday;
tw.tw_yday = tm->tm_yday;
tw.tw_flags = TW_NULL;
if (tm->tm_isdst)
tw.tw_flags |= TW_DST;
tw.tw_zone = 0;
tw.tw_flags &= ~TW_SDAY;
tw.tw_flags |= TW_SEXP;
tw.tw_flags &= ~TW_SZONE;
tw.tw_flags |= TW_SZEXP;
tw.tw_clock = *clock;
return (&tw);
}
/*
* Using a nmh "broken-down" time structure,
* produce a 26-byte date/time string, such as
*
* Tue Jan 14 17:49:03 1992\n\0
*/
char *
dctime (struct tws *tw)
{
static char buffer[26];
if (!tw)
return NULL;
snprintf (buffer, sizeof(buffer), "%.3s %.3s %02d %02d:%02d:%02d %.4d\n",
tw_dotw[tw->tw_wday], tw_moty[tw->tw_mon], tw->tw_mday,
tw->tw_hour, tw->tw_min, tw->tw_sec,
tw->tw_year < 100 ? tw->tw_year + 1900 : tw->tw_year);
return buffer;
}
/*
* Produce a date/time string of the form
*
* Mon, 16 Jun 1992 15:30:48 -700 (or)
* Mon, 16 Jun 1992 15:30:48 EDT
*
* for the current time, as specified by rfc822.
* The first form is required by rfc1123.
*/
char *
dtimenow (int alpha_timezone)
{
time_t clock;
time (&clock);
return dtime (&clock, alpha_timezone);
}
/*
* Using a local calendar time value, produce
* a date/time string of the form
*
* Mon, 16 Jun 1992 15:30:48 -700 (or)
* Mon, 16 Jun 1992 15:30:48 EDT
*
* as specified by rfc822. The first form is required
* by rfc1123 for outgoing messages.
*/
char *
dtime (time_t *clock, int alpha_timezone)
{
if (alpha_timezone)
/* use alpha-numeric timezones */
return dasctime (dlocaltime (clock), TW_NULL);
else
/* use numeric timezones */
return dasctime (dlocaltime (clock), TW_ZONE);
}
/*
* Using a nmh "broken-down" time structure, produce
* a date/time string of the form
*
* Mon, 16 Jun 1992 15:30:48 -0700
*
* as specified by rfc822 and rfc1123.
*/
char *
dasctime (struct tws *tw, int flags)
{
char buffer[80];
static char result[80];
if (!tw)
return NULL;
/* Display timezone if known */
if ((tw->tw_flags & TW_SZONE) == TW_SZNIL)
result[0] = '\0';
else
snprintf(result, sizeof(result), " %s", dtimezone(tw->tw_zone, tw->tw_flags | flags));
snprintf(buffer, sizeof(buffer), "%02d %s %0*d %02d:%02d:%02d%s",
tw->tw_mday, tw_moty[tw->tw_mon],
tw->tw_year < 100 ? 2 : 4, tw->tw_year,
tw->tw_hour, tw->tw_min, tw->tw_sec, result);
if ((tw->tw_flags & TW_SDAY) == TW_SEXP)
snprintf (result, sizeof(result), "%s, %s", tw_dotw[tw->tw_wday], buffer);
else
if ((tw->tw_flags & TW_SDAY) == TW_SNIL)
strncpy (result, buffer, sizeof(result));
else
snprintf (result, sizeof(result), "%s (%s)", buffer, tw_dotw[tw->tw_wday]);
return result;
}
/*
* Get the timezone for given offset
*/
char *
dtimezone (int offset, int flags)
{
int hours, mins;
struct zone *z;
static char buffer[10];
if (offset < 0) {
mins = -((-offset) % 60);
hours = -((-offset) / 60);
} else {
mins = offset % 60;
hours = offset / 60;
}
if (!(flags & TW_ZONE) && mins == 0) {
#if defined(HAVE_TZSET) && defined(HAVE_TZNAME)
tzset();
return ((flags & TW_DST) ? tzname[1] : tzname[0]);
#else
for (z = zones; z->std; z++)
if (z->shift == hours)
return (z->dst && (flags & TW_DST) ? z->dst : z->std);
#endif
}
#ifdef ADJUST_NUMERIC_ONLY_TZ_OFFSETS_WRT_DST
if (flags & TW_DST)
hours += 1;
#endif /* ADJUST_NUMERIC_ONLY_TZ_OFFSETS_WRT_DST */
snprintf (buffer, sizeof(buffer), "%s%02d%02d",
offset < 0 ? "-" : "+", abs (hours), abs (mins));
return buffer;
}
/*
* Convert nmh time structure for local "broken-down"
* time to calendar time (clock value). This routine
* is based on the gtime() routine written by Steven Shafer
* at CMU. It was forwarded to MTR by Jay Lepreau at Utah-CS.
*/
time_t
dmktime (struct tws *tw)
{
int i, sec, min, hour, mday, mon, year;
time_t result;
if (tw->tw_clock != 0)
return tw->tw_clock;
if ((sec = tw->tw_sec) < 0 || sec > 61
|| (min = tw->tw_min) < 0 || min > 59
|| (hour = tw->tw_hour) < 0 || hour > 23
|| (mday = tw->tw_mday) < 1 || mday > 31
|| (mon = tw->tw_mon + 1) < 1 || mon > 12)
return (tw->tw_clock = (time_t) -1);
year = tw->tw_year;
result = 0;
if (year < 1970)
year += 1900;
if (year < 1970)
year += 100;
for (i = 1970; i < year; i++)
result += dysize (i);
if (dysize (year) == 366 && mon >= 3)
result++;
while (--mon)
result += dmsize[mon - 1];
result += mday - 1;
result = 24 * result + hour;
result = 60 * result + min;
result = 60 * result + sec;
result -= 60 * tw->tw_zone;
if (tw->tw_flags & TW_DST)
result -= 60 * 60;
return (tw->tw_clock = result);
}
/*
* Simple calculation of day of the week. Algorithm
* used is Zeller's congruence. We assume that
* if tw->tw_year < 100, then the century = 19.
*/
void
set_dotw (struct tws *tw)
{
int month, day, year, century;
month = tw->tw_mon - 1;
day = tw->tw_mday;
year = tw->tw_year % 100;
century = tw->tw_year < 100 ? 19 : tw->tw_year / 100;
if (month <= 0) {
month += 12;
if (--year < 0) {
year += 100;
century--;
}
}
tw->tw_wday =
((26 * month - 2) / 10 + day + year + year / 4
- 3 * century / 4 + 1) % 7;
if (tw->tw_wday < 0)
tw->tw_wday += 7;
tw->tw_flags &= ~TW_SDAY, tw->tw_flags |= TW_SIMP;
}
/*
* Copy nmh time structure
*/
void
twscopy (struct tws *tb, struct tws *tw)
{
*tb = *tw; /* struct copy */
#if 0
tb->tw_sec = tw->tw_sec;
tb->tw_min = tw->tw_min;
tb->tw_hour = tw->tw_hour;
tb->tw_mday = tw->tw_mday;
tb->tw_mon = tw->tw_mon;
tb->tw_year = tw->tw_year;
tb->tw_wday = tw->tw_wday;
tb->tw_yday = tw->tw_yday;
tb->tw_zone = tw->tw_zone;
tb->tw_clock = tw->tw_clock;
tb->tw_flags = tw->tw_flags;
#endif
}
/*
* Compare two nmh time structures
*/
int
twsort (struct tws *tw1, struct tws *tw2)
{
time_t c1, c2;
if (tw1->tw_clock == 0)
dmktime (tw1);
if (tw2->tw_clock == 0)
dmktime (tw2);
return ((c1 = tw1->tw_clock) > (c2 = tw2->tw_clock) ? 1
: c1 == c2 ? 0 : -1);
}
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