partime.c

早期freebsd实现

/*
 * PARTIME		parse date/time string into a TM structure
 *
 * Returns:
 *	0 if parsing failed
 *	else time values in specified TM structure and zone (unspecified values
 *		set to TMNULL)
 * Notes:
 *	This code is quasi-public; it may be used freely in like software.
 *	It is not to be sold, nor used in licensed software without
 *	permission of the author.
 *	For everyone's benefit, please report bugs and improvements!
 * 	Copyright 1980 by Ken Harrenstien, SRI International.
 *	(ARPANET: KLH @ SRI)
 */

/* Hacknotes:
 *	If parsing changed so that no backup needed, could perhaps modify
 *		to use a FILE input stream.  Need terminator, though.
 *	Perhaps should return 0 on success, else a non-zero error val?
 */

/* $Log: partime.c,v $
 * Revision 5.6  1991/08/19  03:13:55  eggert
 * Update timezones.
 *
 * Revision 5.5  1991/04/21  11:58:18  eggert
 * Don't put , just before } in initializer.
 *
 * Revision 5.4  1990/10/04  06:30:15  eggert
 * Remove date vs time heuristics that fail between 2000 and 2400.
 * Check for overflow when lexing an integer.
 * Parse 'Jan 10 LT' as 'Jan 10, LT', not 'Jan, 10 LT'.
 *
 * Revision 5.3  1990/09/24  18:56:31  eggert
 * Update timezones.
 *
 * Revision 5.2  1990/09/04  08:02:16  eggert
 * Don't parse two-digit years, because it won't work after 1999/12/31.
 * Don't permit 'Aug Aug'.
 *
 * Revision 5.1  1990/08/29  07:13:49  eggert
 * Be able to parse our own date format.  Don't assume year<10000.
 *
 * Revision 5.0  1990/08/22  08:12:40  eggert
 * Switch to GMT and fix the bugs exposed thereby.  Update timezones.
 * Ansify and Posixate.  Fix peekahead and int-size bugs.
 *
 * Revision 1.4  89/05/01  14:48:46  narten
 * fixed #ifdef DEBUG construct
 * 
 * Revision 1.3  88/08/28  14:53:40  eggert
 * Remove unportable "#endif XXX"s.
 * 
 * Revision 1.2  87/03/27  14:21:53  jenkins
 * Port to suns
 * 
 * Revision 1.1  82/05/06  11:38:26  wft
 * Initial revision
 * 
 */

#include "rcsbase.h"

libId(partId, "$Id: partime.c,v 5.6 1991/08/19 03:13:55 eggert Exp $")

#define given(v) (0 <= (v))
#define TMNULL (-1) /* Items not given are given this value */
#define TZ_OFFSET (24*60) /* TMNULL  <  zone_offset - TZ_OFFSET */

struct tmwent {
	char const *went;
	short wval;
	char wflgs;
	char wtype;
};
	/* wflgs */
#define TWTIME 02	/* Word is a time value (absence implies date) */
#define TWDST  04	/* Word is a DST-type timezone */
	/* wtype */
#define TM_MON	1	/* month name */
#define TM_WDAY	2	/* weekday name */
#define TM_ZON	3	/* time zone name */
#define TM_LT	4	/* local time */
#define TM_DST	5	/* daylight savings time */
#define TM_12	6	/* AM, PM, NOON, or MIDNIGHT */
	/* wval (for wtype==TM_12) */
#define T12_AM 1
#define T12_PM 2
#define T12_NOON 12
#define T12_MIDNIGHT 0

static struct tmwent const tmwords [] = {
	{"january",      0, 0, TM_MON},
	{"february",     1, 0, TM_MON},
	{"march",        2, 0, TM_MON},
	{"april",        3, 0, TM_MON},
	{"may",          4, 0, TM_MON},
	{"june",         5, 0, TM_MON},
	{"july",         6, 0, TM_MON},
	{"august",       7, 0, TM_MON},
	{"september",    8, 0, TM_MON},
	{"october",      9, 0, TM_MON},
	{"november",     10, 0, TM_MON},
	{"december",     11, 0, TM_MON},

	{"sunday",       0, 0, TM_WDAY},
	{"monday",       1, 0, TM_WDAY},
	{"tuesday",      2, 0, TM_WDAY},
	{"wednesday",    3, 0, TM_WDAY},
	{"thursday",     4, 0, TM_WDAY},
	{"friday",       5, 0, TM_WDAY},
	{"saturday",     6, 0, TM_WDAY},

	{"gmt",          0*60, TWTIME, TM_ZON},   /* Greenwich */
	{"utc",          0*60, TWTIME, TM_ZON},
	{"ut",           0*60, TWTIME, TM_ZON},
	{"cut",		 0*60, TWTIME, TM_ZON},

	{"nzst",        -12*60, TWTIME, TM_ZON},  /* New Zealand */
	{"jst",         -9*60, TWTIME, TM_ZON},   /* Japan */
	{"kst",         -9*60, TWTIME, TM_ZON},   /* Korea */
	{"ist",         -5*60-30, TWTIME, TM_ZON},/* India */
	{"eet",         -2*60, TWTIME, TM_ZON},   /* Eastern Europe */
	{"cet",         -1*60, TWTIME, TM_ZON},   /* Central Europe */
	{"met",         -1*60, TWTIME, TM_ZON},   /* Middle Europe */
	{"wet",          0*60, TWTIME, TM_ZON},   /* Western Europe */
	{"nst",          3*60+30, TWTIME, TM_ZON},/* Newfoundland */
	{"ast",          4*60, TWTIME, TM_ZON},   /* Atlantic */
	{"est",          5*60, TWTIME, TM_ZON},   /* Eastern */
	{"cst",          6*60, TWTIME, TM_ZON},   /* Central */
	{"mst",          7*60, TWTIME, TM_ZON},   /* Mountain */
	{"pst",          8*60, TWTIME, TM_ZON},   /* Pacific */
	{"akst",         9*60, TWTIME, TM_ZON},   /* Alaska */
	{"hast",         10*60, TWTIME, TM_ZON},  /* Hawaii-Aleutian */
	{"hst",          10*60, TWTIME, TM_ZON},  /* Hawaii */
	{"sst",          11*60, TWTIME, TM_ZON},  /* Samoa */

	{"nzdt",        -12*60, TWTIME+TWDST, TM_ZON},    /* New Zealand */
	{"kdt",         -9*60, TWTIME+TWDST, TM_ZON},     /* Korea */
	{"bst",          0*60, TWTIME+TWDST, TM_ZON},     /* Britain */
	{"ndt",		 3*60+30, TWTIME+TWDST, TM_ZON},  /* Newfoundland */
	{"adt",          4*60, TWTIME+TWDST, TM_ZON},     /* Atlantic */
	{"edt",          5*60, TWTIME+TWDST, TM_ZON},     /* Eastern */
	{"cdt",          6*60, TWTIME+TWDST, TM_ZON},     /* Central */
	{"mdt",          7*60, TWTIME+TWDST, TM_ZON},     /* Mountain */
	{"pdt",          8*60, TWTIME+TWDST, TM_ZON},     /* Pacific */
	{"akdt",         9*60, TWTIME+TWDST, TM_ZON},     /* Alaska */
	{"hadt",         10*60, TWTIME+TWDST, TM_ZON},    /* Hawaii-Aleutian */

#if 0
	/*
	 * The following names are duplicates or are not well attested.
	 * A standard is needed.
	 */
	{"east",        -10*60, TWTIME, TM_ZON},  /* Eastern Australia */
	{"cast",        -9*60-30, TWTIME, TM_ZON},/* Central Australia */
	{"cst",         -8*60, TWTIME, TM_ZON},   /* China */
	{"hkt",         -8*60, TWTIME, TM_ZON},   /* Hong Kong */
	{"sst",         -8*60, TWTIME, TM_ZON},   /* Singapore */
	{"wast",        -8*60, TWTIME, TM_ZON},   /* Western Australia */
	{"?",		-6*60-30, TWTIME, TM_ZON},/* Burma */
	{"?",           -4*60-30, TWTIME, TM_ZON},/* Afghanistan */
	{"it",          -3*60-30, TWTIME, TM_ZON},/* Iran */
	{"ist",         -2*60, TWTIME, TM_ZON},   /* Israel */
	{"mez",		-1*60, TWTIME, TM_ZON},   /* Mittel-Europaeische Zeit */
	{"ast",          1*60, TWTIME, TM_ZON},   /* Azores */
	{"fst",          2*60, TWTIME, TM_ZON},   /* Fernando de Noronha */
	{"bst",          3*60, TWTIME, TM_ZON},   /* Brazil */
	{"wst",          4*60, TWTIME, TM_ZON},   /* Western Brazil */
	{"ast",          5*60, TWTIME, TM_ZON},   /* Acre Brazil */
	{"?",            9*60+30, TWTIME, TM_ZON},/* Marquesas */
	{"?",		 12*60, TWTIME, TM_ZON},  /* Kwajalein */

	{"eadt",        -10*60, TWTIME+TWDST, TM_ZON},    /* Eastern Australia */
	{"cadt",        -9*60-30, TWTIME+TWDST, TM_ZON},  /* Central Australia */
	{"cdt",         -8*60, TWTIME+TWDST, TM_ZON},     /* China */
	{"wadt",        -8*60, TWTIME+TWDST, TM_ZON},     /* Western Australia */
	{"idt",         -2*60, TWTIME+TWDST, TM_ZON},     /* Israel */
	{"eest",        -2*60, TWTIME+TWDST, TM_ZON},     /* Eastern Europe */
	{"cest",        -1*60, TWTIME+TWDST, TM_ZON},     /* Central Europe */
	{"mest",        -1*60, TWTIME+TWDST, TM_ZON},     /* Middle Europe */
	{"mesz",	-1*60, TWTIME+TWDST, TM_ZON},	  /* Mittel-Europaeische Sommerzeit */
	{"west",         0*60, TWTIME+TWDST, TM_ZON},     /* Western Europe */
	{"adt",          1*60, TWTIME+TWDST, TM_ZON},	  /* Azores */
	{"fdt",          2*60, TWTIME+TWDST, TM_ZON},     /* Fernando de Noronha */
	{"edt",          3*60, TWTIME+TWDST, TM_ZON},     /* Eastern Brazil */
	{"wdt",          4*60, TWTIME+TWDST, TM_ZON},     /* Western Brazil */
	{"adt",          5*60, TWTIME+TWDST, TM_ZON},     /* Acre Brazil */
#endif

	{"lt",           0, TWTIME, TM_LT},       /* local time */
	{"dst",          1*60, TWTIME, TM_DST},      /* daylight savings time */
	{"ddst",         2*60, TWTIME, TM_DST},      /* double dst */

	{"am",           T12_AM,	TWTIME, TM_12},
	{"pm",           T12_PM,	TWTIME, TM_12},
	{"noon",         T12_NOON,	TWTIME, TM_12},
	{"midnight",     T12_MIDNIGHT,	TWTIME, TM_12},

	{0, 0, 0, 0}	/* Zero entry to terminate searches */
};

struct token {
	char const *tcp;/* pointer to string */
	int tcnt;	/* # chars */
	char tbrk;	/* "break" char */
	char tbrkl;	/* last break char */
	char tflg;	/* 0 = alpha, 1 = numeric */
	union {         /* Resulting value; */
		int tnum;/* either a #, or */
		struct tmwent const *ttmw;/* a ptr to a tmwent.  */
	} tval;
};

static struct tmwent const*ptmatchstr P((char const*,int,struct tmwent const*));
static int pt12hack P((struct tm *,int));
static int ptitoken P((struct token *));
static int ptstash P((int *,int));
static int pttoken P((struct token *));

	static int
goodzone(t, offset, am)
	register struct token const *t;
	int offset;
	int *am;
{
	register int m;
	if (
		t->tflg  &&
		t->tcnt == 4+offset  &&
		(m = t->tval.tnum) <= 2400  &&
		isdigit(t->tcp[offset]) &&
		(m%=100) < 60
	) {
		m += t->tval.tnum/100 * 60;
		if (t->tcp[offset-1]=='+')
			m = -m;
		*am = m;
		return 1;
	}
	return 0;
}

    int
partime(astr, atm, zone)
char const *astr;
register struct tm *atm;
int *zone;
{
    register int i;
    struct token btoken, atoken;
    int zone_offset; /* minutes west of GMT, plus TZ_OFFSET */
    register char const *cp;
    register char ch;
    int ord, midnoon;
    int *atmfield, dst, m;
    int got1 = 0;

    atm->tm_sec = TMNULL;
    atm->tm_min = TMNULL;
    atm->tm_hour = TMNULL;
    atm->tm_mday = TMNULL;
    atm->tm_mon = TMNULL;
    atm->tm_year = TMNULL;
    atm->tm_wday = TMNULL;
    atm->tm_yday = TMNULL;
    midnoon = TMNULL;		/* and our own temp stuff */
    zone_offset = TMNULL;
    dst = TMNULL;
    btoken.tcnt = btoken.tbrk = 0;
    btoken.tcp = astr;

    for (;; got1=1) {
	if (!ptitoken(&btoken))				/* Get a token */
	  {     if(btoken.tval.tnum) return(0);         /* Read error? */
		if (given(midnoon))			/* EOF, wrap up */
			if (!pt12hack(atm, midnoon))
				return 0;
		if (!given(atm->tm_min))
			atm->tm_min = 0;
		*zone  =
				(given(zone_offset) ? zone_offset-TZ_OFFSET : 0)
			-	(given(dst) ? dst : 0);
		return got1;
	  }
	if(btoken.tflg == 0)		/* Alpha? */
	  {     i = btoken.tval.ttmw->wval;
		switch (btoken.tval.ttmw->wtype) {
		  default:
			return 0;
		  case TM_MON:
			atmfield = &atm->tm_mon;
			break;
		  case TM_WDAY:
			atmfield = &atm->tm_wday;
			break;
		  case TM_DST:
			atmfield = &dst;
			break;
		  case TM_LT:
			if (ptstash(&dst, 0))
				return 0;
			i = 48*60; /* local time magic number -- see maketime() */
			/* fall into */
		  case TM_ZON:
			i += TZ_OFFSET;
			if (btoken.tval.ttmw->wflgs & TWDST)
				if (ptstash(&dst, 60))
					return 0;
			/* Peek ahead for offset immediately afterwards. */
			if (
			    (btoken.tbrk=='-' || btoken.tbrk=='+') &&
			    (atoken=btoken, ++atoken.tcnt, ptitoken(&atoken)) &&
			    goodzone(&atoken, 0, &m)
			) {
				i += m;
				btoken = atoken;
			}
			atmfield = &zone_offset;