freebsd-skq/usr.bin/tar/getdate.c
Tim Kientzle ac90bcdea0 Merge r687-689,691,693-701,720 from libarchive.googlecode.com:
Translate getdate.y into C for portability.  Make the get_date()
function easier to test as well:
 * Have it accept a time_t "now" to use as a reference so that test
   code can verify relative time specifications against known starting
   points.
 * Set up default date after parsing the string so that we
   can use the specified timezone (if any) instead of the local
   default.  Otherwise, local DST makes it almost impossible to
   reliably test time specifications such as "sunday UTC"
2009-03-08 06:03:15 +00:00

1051 lines
28 KiB
C

/*
* This code is in the public domain and has no copyright.
*
* This is a plain C recursive-descent translation of an old
* public-domain YACC grammar that has been used for parsing dates in
* very many open-source projects.
*
* Since the original authors were generous enough to donate their
* work to the public domain, I feel compelled to match their
* generosity.
*
* Tim Kientzle, February 2009.
*/
/*
* Header comment from original getdate.y:
*/
/*
** Originally written by Steven M. Bellovin <smb@research.att.com> while
** at the University of North Carolina at Chapel Hill. Later tweaked by
** a couple of people on Usenet. Completely overhauled by Rich $alz
** <rsalz@bbn.com> and Jim Berets <jberets@bbn.com> in August, 1990;
**
** This grammar has 10 shift/reduce conflicts.
**
** This code is in the public domain and has no copyright.
*/
#ifdef __FreeBSD__
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#endif
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
/* This file defines a single public function. */
time_t get_date(time_t now, char *);
/* Basic time units. */
#define EPOCH 1970
#define MINUTE (60L)
#define HOUR (60L * MINUTE)
#define DAY (24L * HOUR)
/* Daylight-savings mode: on, off, or not yet known. */
enum DSTMODE { DSTon, DSToff, DSTmaybe };
/* Meridian: am or pm. */
enum { tAM, tPM };
/* Token types returned by nexttoken() */
enum { tAGO = 260, tDAY, tDAYZONE, tAMPM, tMONTH, tMONTH_UNIT, tSEC_UNIT,
tUNUMBER, tZONE, tDST };
struct token { int token; time_t value; };
/*
* Parser state.
*/
struct gdstate {
struct token *tokenp; /* Pointer to next token. */
/* HaveXxxx counts how many of this kind of phrase we've seen;
* it's a fatal error to have more than one time, zone, day,
* or date phrase. */
int HaveYear;
int HaveMonth;
int HaveDay;
int HaveWeekDay; /* Day of week */
int HaveTime; /* Hour/minute/second */
int HaveZone; /* timezone and/or DST info */
int HaveRel; /* time offset; we can have more than one */
/* Absolute time values. */
time_t Timezone; /* Seconds offset from GMT */
time_t Day;
time_t Hour;
time_t Minutes;
time_t Month;
time_t Seconds;
time_t Year;
/* DST selection */
enum DSTMODE DSTmode;
/* Day of week accounting, e.g., "3rd Tuesday" */
time_t DayOrdinal; /* "3" in "3rd Tuesday" */
time_t DayNumber; /* "Tuesday" in "3rd Tuesday" */
/* Relative time values: hour/day/week offsets are measured in
* seconds, month/year are counted in months. */
time_t RelMonth;
time_t RelSeconds;
};
/*
* A series of functions that recognize certain common time phrases.
* Each function returns 1 if it managed to make sense of some of the
* tokens, zero otherwise.
*/
/*
* hour:minute or hour:minute:second with optional AM, PM, or numeric
* timezone offset
*/
static int
timephrase(struct gdstate *gds)
{
if (gds->tokenp[0].token == tUNUMBER
&& gds->tokenp[1].token == ':'
&& gds->tokenp[2].token == tUNUMBER
&& gds->tokenp[3].token == ':'
&& gds->tokenp[4].token == tUNUMBER) {
/* "12:14:18" or "22:08:07" */
++gds->HaveTime;
gds->Hour = gds->tokenp[0].value;
gds->Minutes = gds->tokenp[2].value;
gds->Seconds = gds->tokenp[4].value;
gds->tokenp += 5;
}
else if (gds->tokenp[0].token == tUNUMBER
&& gds->tokenp[1].token == ':'
&& gds->tokenp[2].token == tUNUMBER) {
/* "12:14" or "22:08" */
++gds->HaveTime;
gds->Hour = gds->tokenp[0].value;
gds->Minutes = gds->tokenp[2].value;
gds->Seconds = 0;
gds->tokenp += 3;
}
else if (gds->tokenp[0].token == tUNUMBER
&& gds->tokenp[1].token == tAMPM) {
/* "7" is a time if it's followed by "am" or "pm" */
++gds->HaveTime;
gds->Hour = gds->tokenp[0].value;
gds->Minutes = gds->Seconds = 0;
/* We'll handle the AM/PM below. */
gds->tokenp += 1;
} else {
/* We can't handle this. */
return 0;
}
if (gds->tokenp[0].token == tAMPM) {
/* "7:12pm", "12:20:13am" */
if (gds->Hour == 12)
gds->Hour = 0;
if (gds->tokenp[0].value == tPM)
gds->Hour += 12;
gds->tokenp += 1;
}
if (gds->tokenp[0].token == '+'
&& gds->tokenp[1].token == tUNUMBER) {
/* "7:14+0700" */
gds->HaveZone++;
gds->DSTmode = DSToff;
gds->Timezone = - ((gds->tokenp[1].value / 100) * HOUR
+ (gds->tokenp[1].value % 100) * MINUTE);
gds->tokenp += 2;
}
if (gds->tokenp[0].token == '-'
&& gds->tokenp[1].token == tUNUMBER) {
/* "19:14:12-0530" */
gds->HaveZone++;
gds->DSTmode = DSToff;
gds->Timezone = + ((gds->tokenp[1].value / 100) * HOUR
+ (gds->tokenp[1].value % 100) * MINUTE);
gds->tokenp += 2;
}
return 1;
}
/*
* Timezone name, possibly including DST.
*/
static int
zonephrase(struct gdstate *gds)
{
if (gds->tokenp[0].token == tZONE
&& gds->tokenp[1].token == tDST) {
gds->HaveZone++;
gds->Timezone = gds->tokenp[0].value;
gds->DSTmode = DSTon;
gds->tokenp += 1;
return 1;
}
if (gds->tokenp[0].token == tZONE) {
gds->HaveZone++;
gds->Timezone = gds->tokenp[0].value;
gds->DSTmode = DSToff;
gds->tokenp += 1;
return 1;
}
if (gds->tokenp[0].token == tDAYZONE) {
gds->HaveZone++;
gds->Timezone = gds->tokenp[0].value;
gds->DSTmode = DSTon;
gds->tokenp += 1;
return 1;
}
return 0;
}
/*
* Year/month/day in various combinations.
*/
static int
datephrase(struct gdstate *gds)
{
if (gds->tokenp[0].token == tUNUMBER
&& gds->tokenp[1].token == '/'
&& gds->tokenp[2].token == tUNUMBER
&& gds->tokenp[3].token == '/'
&& gds->tokenp[4].token == tUNUMBER) {
gds->HaveYear++;
gds->HaveMonth++;
gds->HaveDay++;
if (gds->tokenp[0].value >= 13) {
/* First number is big: 2004/01/29, 99/02/17 */
gds->Year = gds->tokenp[0].value;
gds->Month = gds->tokenp[2].value;
gds->Day = gds->tokenp[4].value;
} else if ((gds->tokenp[4].value >= 13) || (gds->tokenp[2].value >= 13)) {
/* Last number is big: 01/07/98 */
/* Middle number is big: 01/29/04 */
gds->Month = gds->tokenp[0].value;
gds->Day = gds->tokenp[2].value;
gds->Year = gds->tokenp[4].value;
} else {
/* No significant clues: 02/03/04 */
gds->Month = gds->tokenp[0].value;
gds->Day = gds->tokenp[2].value;
gds->Year = gds->tokenp[4].value;
}
gds->tokenp += 5;
return 1;
}
if (gds->tokenp[0].token == tUNUMBER
&& gds->tokenp[1].token == '/'
&& gds->tokenp[2].token == tUNUMBER) {
/* "1/15" */
gds->HaveMonth++;
gds->HaveDay++;
gds->Month = gds->tokenp[0].value;
gds->Day = gds->tokenp[2].value;
gds->tokenp += 3;
return 1;
}
if (gds->tokenp[0].token == tUNUMBER
&& gds->tokenp[1].token == '-'
&& gds->tokenp[2].token == tUNUMBER
&& gds->tokenp[3].token == '-'
&& gds->tokenp[4].token == tUNUMBER) {
/* ISO 8601 format. yyyy-mm-dd. */
gds->HaveYear++;
gds->HaveMonth++;
gds->HaveDay++;
gds->Year = gds->tokenp[0].value;
gds->Month = gds->tokenp[2].value;
gds->Day = gds->tokenp[4].value;
gds->tokenp += 5;
return 1;
}
if (gds->tokenp[0].token == tUNUMBER
&& gds->tokenp[1].token == '-'
&& gds->tokenp[2].token == tMONTH
&& gds->tokenp[3].token == '-'
&& gds->tokenp[4].token == tUNUMBER) {
gds->HaveYear++;
gds->HaveMonth++;
gds->HaveDay++;
if (gds->tokenp[0].value > 31) {
/* e.g. 1992-Jun-17 */
gds->Year = gds->tokenp[0].value;
gds->Month = gds->tokenp[2].value;
gds->Day = gds->tokenp[4].value;
} else {
/* e.g. 17-JUN-1992. */
gds->Day = gds->tokenp[0].value;
gds->Month = gds->tokenp[2].value;
gds->Year = gds->tokenp[4].value;
}
gds->tokenp += 5;
return 1;
}
if (gds->tokenp[0].token == tMONTH
&& gds->tokenp[1].token == tUNUMBER
&& gds->tokenp[2].token == ','
&& gds->tokenp[3].token == tUNUMBER) {
/* "June 17, 2001" */
gds->HaveYear++;
gds->HaveMonth++;
gds->HaveDay++;
gds->Month = gds->tokenp[0].value;
gds->Day = gds->tokenp[1].value;
gds->Year = gds->tokenp[3].value;
gds->tokenp += 4;
return 1;
}
if (gds->tokenp[0].token == tMONTH
&& gds->tokenp[1].token == tUNUMBER) {
/* "May 3" */
gds->HaveMonth++;
gds->HaveDay++;
gds->Month = gds->tokenp[0].value;
gds->Day = gds->tokenp[1].value;
gds->tokenp += 2;
return 1;
}
if (gds->tokenp[0].token == tUNUMBER
&& gds->tokenp[1].token == tMONTH
&& gds->tokenp[2].token == tUNUMBER) {
/* "12 Sept 1997" */
gds->HaveYear++;
gds->HaveMonth++;
gds->HaveDay++;
gds->Day = gds->tokenp[0].value;
gds->Month = gds->tokenp[1].value;
gds->Year = gds->tokenp[2].value;
gds->tokenp += 3;
return 1;
}
if (gds->tokenp[0].token == tUNUMBER
&& gds->tokenp[1].token == tMONTH) {
/* "12 Sept" */
gds->HaveMonth++;
gds->HaveDay++;
gds->Day = gds->tokenp[0].value;
gds->Month = gds->tokenp[1].value;
gds->tokenp += 2;
return 1;
}
return 0;
}
/*
* Relative time phrase: "tomorrow", "yesterday", "+1 hour", etc.
*/
static int
relunitphrase(struct gdstate *gds)
{
if (gds->tokenp[0].token == '-'
&& gds->tokenp[1].token == tUNUMBER
&& gds->tokenp[2].token == tSEC_UNIT) {
/* "-3 hours" */
gds->HaveRel++;
gds->RelSeconds -= gds->tokenp[1].value * gds->tokenp[2].value;
gds->tokenp += 3;
return 1;
}
if (gds->tokenp[0].token == '+'
&& gds->tokenp[1].token == tUNUMBER
&& gds->tokenp[2].token == tSEC_UNIT) {
/* "+1 minute" */
gds->HaveRel++;
gds->RelSeconds += gds->tokenp[1].value * gds->tokenp[2].value;
gds->tokenp += 3;
return 1;
}
if (gds->tokenp[0].token == tUNUMBER
&& gds->tokenp[1].token == tSEC_UNIT) {
/* "1 day" */
gds->HaveRel++;
gds->RelSeconds += gds->tokenp[1].value * gds->tokenp[2].value;
gds->tokenp += 3;
return 1;
}
if (gds->tokenp[0].token == '-'
&& gds->tokenp[1].token == tUNUMBER
&& gds->tokenp[2].token == tMONTH_UNIT) {
/* "-3 months" */
gds->HaveRel++;
gds->RelMonth -= gds->tokenp[1].value * gds->tokenp[2].value;
gds->tokenp += 3;
return 1;
}
if (gds->tokenp[0].token == '+'
&& gds->tokenp[1].token == tUNUMBER
&& gds->tokenp[2].token == tMONTH_UNIT) {
/* "+5 years" */
gds->HaveRel++;
gds->RelMonth += gds->tokenp[1].value * gds->tokenp[2].value;
gds->tokenp += 3;
return 1;
}
if (gds->tokenp[0].token == tUNUMBER
&& gds->tokenp[1].token == tMONTH_UNIT) {
/* "2 years" */
gds->HaveRel++;
gds->RelMonth += gds->tokenp[0].value * gds->tokenp[1].value;
gds->tokenp += 2;
return 1;
}
if (gds->tokenp[0].token == tSEC_UNIT) {
/* "now", "tomorrow" */
gds->HaveRel++;
gds->RelSeconds += gds->tokenp[0].value;
++gds->tokenp;
return 1;
}
if (gds->tokenp[0].token == tMONTH_UNIT) {
/* "month" */
gds->HaveRel++;
gds->RelMonth += gds->tokenp[0].value;
gds->tokenp += 1;
return 1;
}
return 0;
}
/*
* Day of the week specification.
*/
static int
dayphrase(struct gdstate *gds)
{
if (gds->tokenp[0].token == tDAY) {
/* "tues", "wednesday," */
gds->HaveWeekDay++;
gds->DayOrdinal = 1;
gds->DayNumber = gds->tokenp[0].value;
gds->tokenp += 1;
if (gds->tokenp[0].token == ',')
gds->tokenp += 1;
return 1;
}
if (gds->tokenp[0].token == tUNUMBER
&& gds->tokenp[1].token == tDAY) {
/* "second tues" "3 wed" */
gds->HaveWeekDay++;
gds->DayOrdinal = gds->tokenp[0].value;
gds->DayNumber = gds->tokenp[1].value;
gds->tokenp += 2;
return 1;
}
return 0;
}
/*
* Try to match a phrase using one of the above functions.
* This layer also deals with a couple of generic issues.
*/
static int
phrase(struct gdstate *gds)
{
if (timephrase(gds))
return 1;
if (zonephrase(gds))
return 1;
if (datephrase(gds))
return 1;
if (dayphrase(gds))
return 1;
if (relunitphrase(gds)) {
if (gds->tokenp[0].token == tAGO) {
gds->RelSeconds = -gds->RelSeconds;
gds->RelMonth = -gds->RelMonth;
gds->tokenp += 1;
}
return 1;
}
/* Bare numbers sometimes have meaning. */
if (gds->tokenp[0].token == tUNUMBER) {
if (gds->HaveTime && !gds->HaveYear && !gds->HaveRel) {
gds->HaveYear++;
gds->Year = gds->tokenp[0].value;
gds->tokenp += 1;
return 1;
}
if(gds->tokenp[0].value > 10000) {
/* "20040301" */
gds->HaveYear++;
gds->HaveMonth++;
gds->HaveDay++;
gds->Day= (gds->tokenp[0].value)%100;
gds->Month= (gds->tokenp[0].value/100)%100;
gds->Year = gds->tokenp[0].value/10000;
gds->tokenp += 1;
return 1;
}
if (gds->tokenp[0].value < 24) {
gds->HaveTime++;
gds->Hour = gds->tokenp[0].value;
gds->Minutes = 0;
gds->Seconds = 0;
gds->tokenp += 1;
return 1;
}
if ((gds->tokenp[0].value / 100 < 24)
&& (gds->tokenp[0].value % 100 < 60)) {
/* "513" is same as "5:13" */
gds->Hour = gds->tokenp[0].value / 100;
gds->Minutes = gds->tokenp[0].value % 100;
gds->Seconds = 0;
gds->tokenp += 1;
return 1;
}
}
return 0;
}
/*
* A dictionary of time words.
*/
static struct LEXICON {
size_t abbrev;
const char *name;
int type;
time_t value;
} const TimeWords[] = {
/* am/pm */
{ 0, "am", tAMPM, tAM },
{ 0, "pm", tAMPM, tPM },
/* Month names. */
{ 3, "january", tMONTH, 1 },
{ 3, "february", tMONTH, 2 },
{ 3, "march", tMONTH, 3 },
{ 3, "april", tMONTH, 4 },
{ 3, "may", tMONTH, 5 },
{ 3, "june", tMONTH, 6 },
{ 3, "july", tMONTH, 7 },
{ 3, "august", tMONTH, 8 },
{ 3, "september", tMONTH, 9 },
{ 3, "october", tMONTH, 10 },
{ 3, "november", tMONTH, 11 },
{ 3, "december", tMONTH, 12 },
/* Days of the week. */
{ 2, "sunday", tDAY, 0 },
{ 3, "monday", tDAY, 1 },
{ 2, "tuesday", tDAY, 2 },
{ 3, "wednesday", tDAY, 3 },
{ 2, "thursday", tDAY, 4 },
{ 2, "friday", tDAY, 5 },
{ 2, "saturday", tDAY, 6 },
/* Timezones: Offsets are in seconds. */
{ 0, "gmt", tZONE, 0*HOUR }, /* Greenwich Mean */
{ 0, "ut", tZONE, 0*HOUR }, /* Universal (Coordinated) */
{ 0, "utc", tZONE, 0*HOUR },
{ 0, "wet", tZONE, 0*HOUR }, /* Western European */
{ 0, "bst", tDAYZONE, 0*HOUR }, /* British Summer */
{ 0, "wat", tZONE, 1*HOUR }, /* West Africa */
{ 0, "at", tZONE, 2*HOUR }, /* Azores */
/* { 0, "bst", tZONE, 3*HOUR }, */ /* Brazil Standard: Conflict */
/* { 0, "gst", tZONE, 3*HOUR }, */ /* Greenland Standard: Conflict*/
{ 0, "nft", tZONE, 3*HOUR+30*MINUTE }, /* Newfoundland */
{ 0, "nst", tZONE, 3*HOUR+30*MINUTE }, /* Newfoundland Standard */
{ 0, "ndt", tDAYZONE, 3*HOUR+30*MINUTE }, /* Newfoundland Daylight */
{ 0, "ast", tZONE, 4*HOUR }, /* Atlantic Standard */
{ 0, "adt", tDAYZONE, 4*HOUR }, /* Atlantic Daylight */
{ 0, "est", tZONE, 5*HOUR }, /* Eastern Standard */
{ 0, "edt", tDAYZONE, 5*HOUR }, /* Eastern Daylight */
{ 0, "cst", tZONE, 6*HOUR }, /* Central Standard */
{ 0, "cdt", tDAYZONE, 6*HOUR }, /* Central Daylight */
{ 0, "mst", tZONE, 7*HOUR }, /* Mountain Standard */
{ 0, "mdt", tDAYZONE, 7*HOUR }, /* Mountain Daylight */
{ 0, "pst", tZONE, 8*HOUR }, /* Pacific Standard */
{ 0, "pdt", tDAYZONE, 8*HOUR }, /* Pacific Daylight */
{ 0, "yst", tZONE, 9*HOUR }, /* Yukon Standard */
{ 0, "ydt", tDAYZONE, 9*HOUR }, /* Yukon Daylight */
{ 0, "hst", tZONE, 10*HOUR }, /* Hawaii Standard */
{ 0, "hdt", tDAYZONE, 10*HOUR }, /* Hawaii Daylight */
{ 0, "cat", tZONE, 10*HOUR }, /* Central Alaska */
{ 0, "ahst", tZONE, 10*HOUR }, /* Alaska-Hawaii Standard */
{ 0, "nt", tZONE, 11*HOUR }, /* Nome */
{ 0, "idlw", tZONE, 12*HOUR }, /* Intl Date Line West */
{ 0, "cet", tZONE, -1*HOUR }, /* Central European */
{ 0, "met", tZONE, -1*HOUR }, /* Middle European */
{ 0, "mewt", tZONE, -1*HOUR }, /* Middle European Winter */
{ 0, "mest", tDAYZONE, -1*HOUR }, /* Middle European Summer */
{ 0, "swt", tZONE, -1*HOUR }, /* Swedish Winter */
{ 0, "sst", tDAYZONE, -1*HOUR }, /* Swedish Summer */
{ 0, "fwt", tZONE, -1*HOUR }, /* French Winter */
{ 0, "fst", tDAYZONE, -1*HOUR }, /* French Summer */
{ 0, "eet", tZONE, -2*HOUR }, /* Eastern Eur, USSR Zone 1 */
{ 0, "bt", tZONE, -3*HOUR }, /* Baghdad, USSR Zone 2 */
{ 0, "it", tZONE, -3*HOUR-30*MINUTE },/* Iran */
{ 0, "zp4", tZONE, -4*HOUR }, /* USSR Zone 3 */
{ 0, "zp5", tZONE, -5*HOUR }, /* USSR Zone 4 */
{ 0, "ist", tZONE, -5*HOUR-30*MINUTE },/* Indian Standard */
{ 0, "zp6", tZONE, -6*HOUR }, /* USSR Zone 5 */
/* { 0, "nst", tZONE, -6.5*HOUR }, */ /* North Sumatra: Conflict */
/* { 0, "sst", tZONE, -7*HOUR }, */ /* So Sumatra, USSR 6: Conflict */
{ 0, "wast", tZONE, -7*HOUR }, /* West Australian Standard */
{ 0, "wadt", tDAYZONE, -7*HOUR }, /* West Australian Daylight */
{ 0, "jt", tZONE, -7*HOUR-30*MINUTE },/* Java (3pm in Cronusland!)*/
{ 0, "cct", tZONE, -8*HOUR }, /* China Coast, USSR Zone 7 */
{ 0, "jst", tZONE, -9*HOUR }, /* Japan Std, USSR Zone 8 */
{ 0, "cast", tZONE, -9*HOUR-30*MINUTE },/* Ctrl Australian Std */
{ 0, "cadt", tDAYZONE, -9*HOUR-30*MINUTE },/* Ctrl Australian Daylt */
{ 0, "east", tZONE, -10*HOUR }, /* Eastern Australian Std */
{ 0, "eadt", tDAYZONE, -10*HOUR }, /* Eastern Australian Daylt */
{ 0, "gst", tZONE, -10*HOUR }, /* Guam Std, USSR Zone 9 */
{ 0, "nzt", tZONE, -12*HOUR }, /* New Zealand */
{ 0, "nzst", tZONE, -12*HOUR }, /* New Zealand Standard */
{ 0, "nzdt", tDAYZONE, -12*HOUR }, /* New Zealand Daylight */
{ 0, "idle", tZONE, -12*HOUR }, /* Intl Date Line East */
{ 0, "dst", tDST, 0 },
/* Time units. */
{ 4, "years", tMONTH_UNIT, 12 },
{ 5, "months", tMONTH_UNIT, 1 },
{ 9, "fortnights", tSEC_UNIT, 14 * DAY },
{ 4, "weeks", tSEC_UNIT, 7 * DAY },
{ 3, "days", tSEC_UNIT, DAY },
{ 4, "hours", tSEC_UNIT, HOUR },
{ 3, "minutes", tSEC_UNIT, MINUTE },
{ 3, "seconds", tSEC_UNIT, 1 },
/* Relative-time words. */
{ 0, "tomorrow", tSEC_UNIT, DAY },
{ 0, "yesterday", tSEC_UNIT, -DAY },
{ 0, "today", tSEC_UNIT, 0 },
{ 0, "now", tSEC_UNIT, 0 },
{ 0, "last", tUNUMBER, -1 },
{ 0, "this", tSEC_UNIT, 0 },
{ 0, "next", tUNUMBER, 2 },
{ 0, "first", tUNUMBER, 1 },
{ 0, "1st", tUNUMBER, 1 },
/* { 0, "second", tUNUMBER, 2 }, */
{ 0, "2nd", tUNUMBER, 2 },
{ 0, "third", tUNUMBER, 3 },
{ 0, "3rd", tUNUMBER, 3 },
{ 0, "fourth", tUNUMBER, 4 },
{ 0, "4th", tUNUMBER, 4 },
{ 0, "fifth", tUNUMBER, 5 },
{ 0, "5th", tUNUMBER, 5 },
{ 0, "sixth", tUNUMBER, 6 },
{ 0, "seventh", tUNUMBER, 7 },
{ 0, "eighth", tUNUMBER, 8 },
{ 0, "ninth", tUNUMBER, 9 },
{ 0, "tenth", tUNUMBER, 10 },
{ 0, "eleventh", tUNUMBER, 11 },
{ 0, "twelfth", tUNUMBER, 12 },
{ 0, "ago", tAGO, 1 },
/* Military timezones. */
{ 0, "a", tZONE, 1*HOUR },
{ 0, "b", tZONE, 2*HOUR },
{ 0, "c", tZONE, 3*HOUR },
{ 0, "d", tZONE, 4*HOUR },
{ 0, "e", tZONE, 5*HOUR },
{ 0, "f", tZONE, 6*HOUR },
{ 0, "g", tZONE, 7*HOUR },
{ 0, "h", tZONE, 8*HOUR },
{ 0, "i", tZONE, 9*HOUR },
{ 0, "k", tZONE, 10*HOUR },
{ 0, "l", tZONE, 11*HOUR },
{ 0, "m", tZONE, 12*HOUR },
{ 0, "n", tZONE, -1*HOUR },
{ 0, "o", tZONE, -2*HOUR },
{ 0, "p", tZONE, -3*HOUR },
{ 0, "q", tZONE, -4*HOUR },
{ 0, "r", tZONE, -5*HOUR },
{ 0, "s", tZONE, -6*HOUR },
{ 0, "t", tZONE, -7*HOUR },
{ 0, "u", tZONE, -8*HOUR },
{ 0, "v", tZONE, -9*HOUR },
{ 0, "w", tZONE, -10*HOUR },
{ 0, "x", tZONE, -11*HOUR },
{ 0, "y", tZONE, -12*HOUR },
{ 0, "z", tZONE, 0*HOUR },
/* End of table. */
{ 0, NULL, 0, 0 }
};
/*
* Convert hour/minute/second to count of seconds.
*/
static time_t
ToSeconds(time_t Hours, time_t Minutes, time_t Seconds)
{
if (Minutes < 0 || Minutes > 59 || Seconds < 0 || Seconds > 59)
return -1;
if (Hours < 0 || Hours > 23)
return -1;
return Hours * HOUR + Minutes * MINUTE + Seconds;
}
/*
* Year is either:
* = A number from 0 to 99, which means a year from 1970 to 2069, or
* = The actual year (>=100).
*/
static time_t
Convert(time_t Month, time_t Day, time_t Year,
time_t Hours, time_t Minutes, time_t Seconds,
time_t Timezone, enum DSTMODE DSTmode)
{
static int DaysInMonth[12] = {
31, 0, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
};
time_t tod;
time_t Julian;
int i;
if (Year < 69)
Year += 2000;
else if (Year < 100)
Year += 1900;
DaysInMonth[1] = Year % 4 == 0 && (Year % 100 != 0 || Year % 400 == 0)
? 29 : 28;
/* Checking for 2038 bogusly assumes that time_t is 32 bits. But
I'm too lazy to try to check for time_t overflow in another way. */
if (Year < EPOCH || Year > 2038
|| Month < 1 || Month > 12
/* Lint fluff: "conversion from long may lose accuracy" */
|| Day < 1 || Day > DaysInMonth[(int)--Month])
return -1;
Julian = Day - 1;
for (i = 0; i < Month; i++)
Julian += DaysInMonth[i];
for (i = EPOCH; i < Year; i++)
Julian += 365 + (i % 4 == 0);
Julian *= DAY;
Julian += Timezone;
if ((tod = ToSeconds(Hours, Minutes, Seconds)) < 0)
return -1;
Julian += tod;
if (DSTmode == DSTon
|| (DSTmode == DSTmaybe && localtime(&Julian)->tm_isdst))
Julian -= HOUR;
return Julian;
}
static time_t
DSTcorrect(time_t Start, time_t Future)
{
time_t StartDay;
time_t FutureDay;
StartDay = (localtime(&Start)->tm_hour + 1) % 24;
FutureDay = (localtime(&Future)->tm_hour + 1) % 24;
return (Future - Start) + (StartDay - FutureDay) * HOUR;
}
static time_t
RelativeDate(time_t Start, time_t zone, int dstmode,
time_t DayOrdinal, time_t DayNumber)
{
struct tm *tm;
time_t t, now;
t = Start - zone;
tm = gmtime(&t);
now = Start;
now += DAY * ((DayNumber - tm->tm_wday + 7) % 7);
now += 7 * DAY * (DayOrdinal <= 0 ? DayOrdinal : DayOrdinal - 1);
if (dstmode == DSTmaybe)
return DSTcorrect(Start, now);
return now - Start;
}
static time_t
RelativeMonth(time_t Start, time_t Timezone, time_t RelMonth)
{
struct tm *tm;
time_t Month;
time_t Year;
if (RelMonth == 0)
return 0;
tm = localtime(&Start);
Month = 12 * (tm->tm_year + 1900) + tm->tm_mon + RelMonth;
Year = Month / 12;
Month = Month % 12 + 1;
return DSTcorrect(Start,
Convert(Month, (time_t)tm->tm_mday, Year,
(time_t)tm->tm_hour, (time_t)tm->tm_min, (time_t)tm->tm_sec,
Timezone, DSTmaybe));
}
/*
* Tokenizer.
*/
static int
nexttoken(char **in, time_t *value)
{
char c;
char buff[64];
for ( ; ; ) {
while (isspace((unsigned char)**in))
++*in;
/* Skip parenthesized comments. */
if (**in == '(') {
int Count = 0;
do {
c = *(*in)++;
if (c == '\0')
return c;
if (c == '(')
Count++;
else if (c == ')')
Count--;
} while (Count > 0);
continue;
}
/* Try the next token in the word table first. */
/* This allows us to match "2nd", for example. */
{
char *src = *in;
const struct LEXICON *tp;
unsigned i = 0;
/* Force to lowercase and strip '.' characters. */
while (*src != '\0'
&& (isalnum((unsigned char)*src) || *src == '.')
&& i < sizeof(buff)-1) {
if (*src != '.') {
if (isupper((unsigned char)*src))
buff[i++] = tolower((unsigned char)*src);
else
buff[i++] = *src;
}
src++;
}
buff[i++] = '\0';
/*
* Find the first match. If the word can be
* abbreviated, make sure we match at least
* the minimum abbreviation.
*/
for (tp = TimeWords; tp->name; tp++) {
size_t abbrev = tp->abbrev;
if (abbrev == 0)
abbrev = strlen(tp->name);
if (strlen(buff) >= abbrev
&& strncmp(tp->name, buff, strlen(buff))
== 0) {
/* Skip over token. */
*in = src;
/* Return the match. */
*value = tp->value;
return tp->type;
}
}
}
/*
* Not in the word table, maybe it's a number. Note:
* Because '-' and '+' have other special meanings, I
* don't deal with signed numbers here.
*/
if (isdigit((unsigned char)(c = **in))) {
for (*value = 0; isdigit((unsigned char)(c = *(*in)++)); )
*value = 10 * *value + c - '0';
(*in)--;
return (tUNUMBER);
}
return *(*in)++;
}
}
#define TM_YEAR_ORIGIN 1900
/* Yield A - B, measured in seconds. */
static long
difftm (struct tm *a, struct tm *b)
{
int ay = a->tm_year + (TM_YEAR_ORIGIN - 1);
int by = b->tm_year + (TM_YEAR_ORIGIN - 1);
int days = (
/* difference in day of year */
a->tm_yday - b->tm_yday
/* + intervening leap days */
+ ((ay >> 2) - (by >> 2))
- (ay/100 - by/100)
+ ((ay/100 >> 2) - (by/100 >> 2))
/* + difference in years * 365 */
+ (long)(ay-by) * 365
);
return (days * DAY + (a->tm_hour - b->tm_hour) * HOUR
+ (a->tm_min - b->tm_min) * MINUTE
+ (a->tm_sec - b->tm_sec));
}
/*
*
* The public function.
*
* TODO: tokens[] array should be dynamically sized.
*/
time_t
get_date(time_t now, char *p)
{
struct token tokens[256];
struct gdstate _gds;
struct token *lasttoken;
struct gdstate *gds;
struct tm local, *tm;
struct tm gmt, *gmt_ptr;
time_t Start;
time_t tod;
long tzone;
/* Clear out the parsed token array. */
memset(tokens, 0, sizeof(tokens));
/* Initialize the parser state. */
memset(&_gds, 0, sizeof(_gds));
gds = &_gds;
/* Look up the current time. */
memset(&local, 0, sizeof(local));
tm = localtime (&now);
if (tm == NULL)
return -1;
local = *tm;
/* Look up UTC if we can and use that to determine the current
* timezone offset. */
memset(&gmt, 0, sizeof(gmt));
gmt_ptr = gmtime (&now);
if (gmt_ptr != NULL) {
/* Copy, in case localtime and gmtime use the same buffer. */
gmt = *gmt_ptr;
}
if (gmt_ptr != NULL)
tzone = difftm (&gmt, &local);
else
/* This system doesn't understand timezones; fake it. */
tzone = 0;
if(local.tm_isdst)
tzone += HOUR;
/* Tokenize the input string. */
lasttoken = tokens;
while ((lasttoken->token = nexttoken(&p, &lasttoken->value)) != 0) {
++lasttoken;
if (lasttoken > tokens + 255)
return -1;
}
gds->tokenp = tokens;
/* Match phrases until we run out of input tokens. */
while (gds->tokenp < lasttoken) {
if (!phrase(gds))
return -1;
}
/* Use current local timezone if none was specified. */
if (!gds->HaveZone) {
gds->Timezone = tzone;
gds->DSTmode = DSTmaybe;
}
/* If a timezone was specified, use that for generating the default
* time components instead of the local timezone. */
if (gds->HaveZone && gmt_ptr != NULL) {
now -= gds->Timezone;
gmt_ptr = gmtime (&now);
if (gmt_ptr != NULL)
local = *gmt_ptr;
now += gds->Timezone;
}
if (!gds->HaveYear)
gds->Year = local.tm_year + 1900;
if (!gds->HaveMonth)
gds->Month = local.tm_mon + 1;
if (!gds->HaveDay)
gds->Day = local.tm_mday;
/* Note: No default for hour/min/sec; a specifier that just
* gives date always refers to 00:00 on that date. */
/* If we saw more than one time, timezone, weekday, year, month,
* or day, then give up. */
if (gds->HaveTime > 1 || gds->HaveZone > 1 || gds->HaveWeekDay > 1
|| gds->HaveYear > 1 || gds->HaveMonth > 1 || gds->HaveDay > 1)
return -1;
/* Compute an absolute time based on whatever absolute information
* we collected. */
if (gds->HaveYear || gds->HaveMonth || gds->HaveDay
|| gds->HaveTime || gds->HaveWeekDay) {
Start = Convert(gds->Month, gds->Day, gds->Year,
gds->Hour, gds->Minutes, gds->Seconds,
gds->Timezone, gds->DSTmode);
if (Start < 0)
return -1;
} else {
Start = now;
if (!gds->HaveRel)
Start -= local.tm_hour * HOUR + local.tm_min * MINUTE
+ local.tm_sec;
}
/* Add the relative offset. */
Start += gds->RelSeconds;
Start += RelativeMonth(Start, gds->Timezone, gds->RelMonth);
/* Adjust for day-of-week offsets. */
if (gds->HaveWeekDay
&& !(gds->HaveYear || gds->HaveMonth || gds->HaveDay)) {
tod = RelativeDate(Start, gds->Timezone,
gds->DSTmode, gds->DayOrdinal, gds->DayNumber);
Start += tod;
}
/* -1 is an error indicator, so return 0 instead of -1 if
* that's the actual time. */
return Start == -1 ? 0 : Start;
}
#if defined(TEST)
/* ARGSUSED */
int
main(int argc, char **argv)
{
time_t d;
while (*++argv != NULL) {
(void)printf("Input: %s\n", *argv);
d = get_date(*argv);
if (d == -1)
(void)printf("Bad format - couldn't convert.\n");
else
(void)printf("Output: %s\n", ctime(&d));
}
exit(0);
/* NOTREACHED */
}
#endif /* defined(TEST) */