freebsd-nq/usr.bin/tar/getdate.y
Tim Kientzle 6b422e20c1 Extended attribute support on write for Linux; FreeBSD hooks are
forthcoming.  This commit also has a number of style(9) fixes and
minor corrections so the code works better with the build system being
used for non-FreeBSD builds.

Many thanks to: Jaakko Heinonen, who proposed a mechanism for extended
attribute support and implemented both the machine-independent portion
and the Linux-specific portion.
2006-03-21 17:03:51 +00:00

811 lines
19 KiB
Plaintext
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

%{
/*
* March 2005: Further modified and simplified by Tim Kientzle:
* Eliminate minutes-based calculations (just do everything in
* seconds), have lexer only recognize unsigned integers (handle '+'
* and '-' characters in grammar), combine tables into one table with
* explicit abbreviation notes, do am/pm adjustments in the grammar
* (eliminate some state variables and post-processing). Among other
* things, these changes eliminated two shift/reduce conflicts. (Went
* from 10 to 8.)
*/
/*
** 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 $alz
** <rsalz@bbn.com> and Jim Berets <jberets@bbn.com> in August, 1990;
**
** This grammar has 10 shift/reduce conflicts.
**
** This code is in the public domain and has no copyright.
*/
/* SUPPRESS 287 on yaccpar_sccsid *//* Unused static variable */
/* SUPPRESS 288 on yyerrlab *//* Label unused */
#ifdef __FreeBSD__
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#endif
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#define yyparse getdate_yyparse
#define yylex getdate_yylex
#define yyerror getdate_yyerror
static int yyparse(void);
static int yylex(void);
static int yyerror(const char *);
time_t get_date(char *);
#define EPOCH 1970
#define HOUR(x) ((time_t)(x) * 60)
#define SECSPERDAY (24L * 60L * 60L)
/*
** Daylight-savings mode: on, off, or not yet known.
*/
typedef enum _DSTMODE {
DSTon, DSToff, DSTmaybe
} DSTMODE;
/*
** Meridian: am or pm.
*/
enum { tAM, tPM };
/*
** Global variables. We could get rid of most of these by using a good
** union as the yacc stack. (This routine was originally written before
** yacc had the %union construct.) Maybe someday; right now we only use
** the %union very rarely.
*/
static char *yyInput;
static DSTMODE yyDSTmode;
static time_t yyDayOrdinal;
static time_t yyDayNumber;
static int yyHaveDate;
static int yyHaveDay;
static int yyHaveRel;
static int yyHaveTime;
static int yyHaveZone;
static time_t yyTimezone;
static time_t yyDay;
static time_t yyHour;
static time_t yyMinutes;
static time_t yyMonth;
static time_t yySeconds;
static time_t yyYear;
static time_t yyRelMonth;
static time_t yyRelSeconds;
%}
%union {
time_t Number;
}
%token tAGO tDAY tDAYZONE tAMPM tMONTH tMONTH_UNIT tSEC_UNIT tUNUMBER
%token tZONE tDST
%type <Number> tDAY tDAYZONE tMONTH tMONTH_UNIT
%type <Number> tSEC_UNIT tUNUMBER tZONE tAMPM
%%
spec : /* NULL */
| spec item
;
item : time { yyHaveTime++; }
| zone { yyHaveZone++; }
| date { yyHaveDate++; }
| day { yyHaveDay++; }
| rel { yyHaveRel++; }
| number
;
time : tUNUMBER tAMPM {
/* "7am" */
yyHour = $1;
if (yyHour == 12)
yyHour = 0;
yyMinutes = 0;
yySeconds = 0;
if ($2 == tPM)
yyHour += 12;
}
| bare_time {
/* "7:12:18" "19:17" */
}
| bare_time tAMPM {
/* "7:12pm", "12:20:13am" */
if (yyHour == 12)
yyHour = 0;
if ($2 == tPM)
yyHour += 12;
}
| bare_time '+' tUNUMBER {
/* "7:14+0700" */
yyDSTmode = DSToff;
yyTimezone = - ($3 % 100 + ($3 / 100) * 60);
}
| bare_time '-' tUNUMBER {
/* "19:14:12-0530" */
yyDSTmode = DSToff;
yyTimezone = + ($3 % 100 + ($3 / 100) * 60);
}
;
bare_time : tUNUMBER ':' tUNUMBER {
yyHour = $1;
yyMinutes = $3;
yySeconds = 0;
}
| tUNUMBER ':' tUNUMBER ':' tUNUMBER {
yyHour = $1;
yyMinutes = $3;
yySeconds = $5;
}
;
zone : tZONE {
yyTimezone = $1;
yyDSTmode = DSToff;
}
| tDAYZONE {
yyTimezone = $1;
yyDSTmode = DSTon;
}
| tZONE tDST {
yyTimezone = $1;
yyDSTmode = DSTon;
}
;
day : tDAY {
yyDayOrdinal = 1;
yyDayNumber = $1;
}
| tDAY ',' {
/* "tue," "wednesday," */
yyDayOrdinal = 1;
yyDayNumber = $1;
}
| tUNUMBER tDAY {
/* "second tues" "3 wed" */
yyDayOrdinal = $1;
yyDayNumber = $2;
}
;
date : tUNUMBER '/' tUNUMBER {
/* "1/15" */
yyMonth = $1;
yyDay = $3;
}
| tUNUMBER '/' tUNUMBER '/' tUNUMBER {
if ($1 >= 13) {
/* First number is big: 2004/01/29, 99/02/17 */
yyYear = $1;
yyMonth = $3;
yyDay = $5;
} else if (($5 >= 13) || ($3 >= 13)) {
/* Last number is big: 01/07/98 */
/* Middle number is big: 01/29/04 */
yyMonth = $1;
yyDay = $3;
yyYear = $5;
} else {
/* No significant clues: 02/03/04 */
yyMonth = $1;
yyDay = $3;
yyYear = $5;
}
}
| tUNUMBER '-' tUNUMBER '-' tUNUMBER {
/* ISO 8601 format. yyyy-mm-dd. */
yyYear = $1;
yyMonth = $3;
yyDay = $5;
}
| tUNUMBER '-' tMONTH '-' tUNUMBER {
if ($1 > 31) {
/* e.g. 1992-Jun-17 */
yyYear = $1;
yyMonth = $3;
yyDay = $5;
} else {
/* e.g. 17-JUN-1992. */
yyDay = $1;
yyMonth = $3;
yyYear = $5;
}
}
| tMONTH tUNUMBER {
/* "May 3" */
yyMonth = $1;
yyDay = $2;
}
| tMONTH tUNUMBER ',' tUNUMBER {
/* "June 17, 2001" */
yyMonth = $1;
yyDay = $2;
yyYear = $4;
}
| tUNUMBER tMONTH {
/* "12 Sept" */
yyDay = $1;
yyMonth = $2;
}
| tUNUMBER tMONTH tUNUMBER {
/* "12 Sept 1997" */
yyDay = $1;
yyMonth = $2;
yyYear = $3;
}
;
rel : relunit tAGO {
yyRelSeconds = -yyRelSeconds;
yyRelMonth = -yyRelMonth;
}
| relunit
;
relunit : '-' tUNUMBER tSEC_UNIT {
/* "-3 hours" */
yyRelSeconds -= $2 * $3;
}
| '+' tUNUMBER tSEC_UNIT {
/* "+1 minute" */
yyRelSeconds += $2 * $3;
}
| tUNUMBER tSEC_UNIT {
/* "1 day" */
yyRelSeconds += $1;
}
| tSEC_UNIT {
/* "hour" */
yyRelSeconds++;
}
| '-' tUNUMBER tMONTH_UNIT {
/* "-3 months" */
yyRelMonth -= $2 * $3;
}
| '+' tUNUMBER tMONTH_UNIT {
/* "+5 years" */
yyRelMonth += $2 * $3;
}
| tUNUMBER tMONTH_UNIT {
/* "2 years" */
yyRelMonth += $1 * $2;
}
| tMONTH_UNIT {
/* "6 months" */
yyRelMonth += $1;
}
;
number : tUNUMBER {
if (yyHaveTime && yyHaveDate && !yyHaveRel)
yyYear = $1;
else {
if($1>10000) {
/* "20040301" */
yyHaveDate++;
yyDay= ($1)%100;
yyMonth= ($1/100)%100;
yyYear = $1/10000;
}
else {
/* "513" is same as "5:13" */
yyHaveTime++;
if ($1 < 100) {
yyHour = $1;
yyMinutes = 0;
}
else {
yyHour = $1 / 100;
yyMinutes = $1 % 100;
}
yySeconds = 0;
}
}
}
;
%%
static struct TABLE {
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 minutes. */
{ 0, "gmt", tZONE, HOUR( 0) }, /* Greenwich Mean */
{ 0, "ut", tZONE, HOUR( 0) }, /* Universal (Coordinated) */
{ 0, "utc", tZONE, HOUR( 0) },
{ 0, "wet", tZONE, HOUR( 0) }, /* Western European */
{ 0, "bst", tDAYZONE, HOUR( 0) }, /* British Summer */
{ 0, "wat", tZONE, HOUR( 1) }, /* West Africa */
{ 0, "at", tZONE, HOUR( 2) }, /* Azores */
/* { 0, "bst", tZONE, HOUR( 3) }, */ /* Brazil Standard: Conflict */
/* { 0, "gst", tZONE, HOUR( 3) }, */ /* Greenland Standard: Conflict*/
{ 0, "nft", tZONE, HOUR(3)+30 }, /* Newfoundland */
{ 0, "nst", tZONE, HOUR(3)+30 }, /* Newfoundland Standard */
{ 0, "ndt", tDAYZONE, HOUR(3)+30 }, /* Newfoundland Daylight */
{ 0, "ast", tZONE, HOUR( 4) }, /* Atlantic Standard */
{ 0, "adt", tDAYZONE, HOUR( 4) }, /* Atlantic Daylight */
{ 0, "est", tZONE, HOUR( 5) }, /* Eastern Standard */
{ 0, "edt", tDAYZONE, HOUR( 5) }, /* Eastern Daylight */
{ 0, "cst", tZONE, HOUR( 6) }, /* Central Standard */
{ 0, "cdt", tDAYZONE, HOUR( 6) }, /* Central Daylight */
{ 0, "mst", tZONE, HOUR( 7) }, /* Mountain Standard */
{ 0, "mdt", tDAYZONE, HOUR( 7) }, /* Mountain Daylight */
{ 0, "pst", tZONE, HOUR( 8) }, /* Pacific Standard */
{ 0, "pdt", tDAYZONE, HOUR( 8) }, /* Pacific Daylight */
{ 0, "yst", tZONE, HOUR( 9) }, /* Yukon Standard */
{ 0, "ydt", tDAYZONE, HOUR( 9) }, /* Yukon Daylight */
{ 0, "hst", tZONE, HOUR(10) }, /* Hawaii Standard */
{ 0, "hdt", tDAYZONE, HOUR(10) }, /* Hawaii Daylight */
{ 0, "cat", tZONE, HOUR(10) }, /* Central Alaska */
{ 0, "ahst", tZONE, HOUR(10) }, /* Alaska-Hawaii Standard */
{ 0, "nt", tZONE, HOUR(11) }, /* Nome */
{ 0, "idlw", tZONE, HOUR(12) }, /* Intl Date Line West */
{ 0, "cet", tZONE, -HOUR(1) }, /* Central European */
{ 0, "met", tZONE, -HOUR(1) }, /* Middle European */
{ 0, "mewt", tZONE, -HOUR(1) }, /* Middle European Winter */
{ 0, "mest", tDAYZONE, -HOUR(1) }, /* Middle European Summer */
{ 0, "swt", tZONE, -HOUR(1) }, /* Swedish Winter */
{ 0, "sst", tDAYZONE, -HOUR(1) }, /* Swedish Summer */
{ 0, "fwt", tZONE, -HOUR(1) }, /* French Winter */
{ 0, "fst", tDAYZONE, -HOUR(1) }, /* French Summer */
{ 0, "eet", tZONE, -HOUR(2) }, /* Eastern Eur, USSR Zone 1 */
{ 0, "bt", tZONE, -HOUR(3) }, /* Baghdad, USSR Zone 2 */
{ 0, "it", tZONE, -HOUR(3)-30 },/* Iran */
{ 0, "zp4", tZONE, -HOUR(4) }, /* USSR Zone 3 */
{ 0, "zp5", tZONE, -HOUR(5) }, /* USSR Zone 4 */
{ 0, "ist", tZONE, -HOUR(5)-30 },/* Indian Standard */
{ 0, "zp6", tZONE, -HOUR(6) }, /* USSR Zone 5 */
/* { 0, "nst", tZONE, -HOUR(6.5) }, */ /* North Sumatra: Conflict */
/* { 0, "sst", tZONE, -HOUR(7) }, */ /* So Sumatra, USSR 6: Conflict */
{ 0, "wast", tZONE, -HOUR(7) }, /* West Australian Standard */
{ 0, "wadt", tDAYZONE, -HOUR(7) }, /* West Australian Daylight */
{ 0, "jt", tZONE, -HOUR(7)-30 },/* Java (3pm in Cronusland!)*/
{ 0, "cct", tZONE, -HOUR(8) }, /* China Coast, USSR Zone 7 */
{ 0, "jst", tZONE, -HOUR(9) }, /* Japan Std, USSR Zone 8 */
{ 0, "cast", tZONE, -HOUR(9)-30 },/* Central Australian Std */
{ 0, "cadt", tDAYZONE, -HOUR(9)-30 },/* Central Australian Daylt */
{ 0, "east", tZONE, -HOUR(10) }, /* Eastern Australian Std */
{ 0, "eadt", tDAYZONE, -HOUR(10) }, /* Eastern Australian Daylt */
{ 0, "gst", tZONE, -HOUR(10) }, /* Guam Std, USSR Zone 9 */
{ 0, "nzt", tZONE, -HOUR(12) }, /* New Zealand */
{ 0, "nzst", tZONE, -HOUR(12) }, /* New Zealand Standard */
{ 0, "nzdt", tDAYZONE, -HOUR(12) }, /* New Zealand Daylight */
{ 0, "idle", tZONE, -HOUR(12) }, /* 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 * 24 * 60 * 60 },
{ 4, "weeks", tSEC_UNIT, 7 * 24 * 60 * 60 },
{ 3, "days", tSEC_UNIT, 1 * 24 * 60 * 60 },
{ 4, "hours", tSEC_UNIT, 60 * 60 },
{ 3, "minutes", tSEC_UNIT, 60 },
{ 3, "seconds", tSEC_UNIT, 1 },
/* Relative-time words. */
{ 0, "tomorrow", tSEC_UNIT, 1 * 24 * 60 * 60 },
{ 0, "yesterday", tSEC_UNIT, -1 * 24 * 60 * 60 },
{ 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, HOUR( 1) },
{ 0, "b", tZONE, HOUR( 2) },
{ 0, "c", tZONE, HOUR( 3) },
{ 0, "d", tZONE, HOUR( 4) },
{ 0, "e", tZONE, HOUR( 5) },
{ 0, "f", tZONE, HOUR( 6) },
{ 0, "g", tZONE, HOUR( 7) },
{ 0, "h", tZONE, HOUR( 8) },
{ 0, "i", tZONE, HOUR( 9) },
{ 0, "k", tZONE, HOUR( 10) },
{ 0, "l", tZONE, HOUR( 11) },
{ 0, "m", tZONE, HOUR( 12) },
{ 0, "n", tZONE, HOUR(- 1) },
{ 0, "o", tZONE, HOUR(- 2) },
{ 0, "p", tZONE, HOUR(- 3) },
{ 0, "q", tZONE, HOUR(- 4) },
{ 0, "r", tZONE, HOUR(- 5) },
{ 0, "s", tZONE, HOUR(- 6) },
{ 0, "t", tZONE, HOUR(- 7) },
{ 0, "u", tZONE, HOUR(- 8) },
{ 0, "v", tZONE, HOUR(- 9) },
{ 0, "w", tZONE, HOUR(-10) },
{ 0, "x", tZONE, HOUR(-11) },
{ 0, "y", tZONE, HOUR(-12) },
{ 0, "z", tZONE, HOUR( 0) },
/* End of table. */
{ 0, NULL, 0, 0 }
};
/* ARGSUSED */
static int
yyerror(const char *s)
{
(void)s;
return 0;
}
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 * 60L + Minutes) * 60L + 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, 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 *= SECSPERDAY;
Julian += yyTimezone * 60L;
if ((tod = ToSeconds(Hours, Minutes, Seconds)) < 0)
return -1;
Julian += tod;
if (DSTmode == DSTon
|| (DSTmode == DSTmaybe && localtime(&Julian)->tm_isdst))
Julian -= 60 * 60;
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) * 60L * 60L;
}
static time_t
RelativeDate(time_t Start, time_t DayOrdinal, time_t DayNumber)
{
struct tm *tm;
time_t now;
now = Start;
tm = localtime(&now);
now += SECSPERDAY * ((DayNumber - tm->tm_wday + 7) % 7);
now += 7 * SECSPERDAY * (DayOrdinal <= 0 ? DayOrdinal : DayOrdinal - 1);
return DSTcorrect(Start, now);
}
static time_t
RelativeMonth(time_t Start, 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,
DSTmaybe));
}
static int
yylex(void)
{
char c;
char buff[64];
for ( ; ; ) {
while (isspace(*yyInput))
yyInput++;
/* Skip parenthesized comments. */
if (*yyInput == '(') {
int Count = 0;
do {
c = *yyInput++;
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 = yyInput;
const struct TABLE *tp;
unsigned i = 0;
/* Force to lowercase and strip '.' characters. */
while (*src != '\0'
&& (isalnum(*src) || *src == '.')
&& i < sizeof(buff)-1) {
if (*src != '.') {
if (isupper(*src))
buff[i++] = tolower(*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. */
yyInput = src;
/* Return the match. */
yylval.Number = 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(c = *yyInput)) {
for (yylval.Number = 0; isdigit(c = *yyInput++); )
yylval.Number = 10 * yylval.Number + c - '0';
yyInput--;
return (tUNUMBER);
}
return (*yyInput++);
}
}
#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 (60*(60*(24*days + (a->tm_hour - b->tm_hour))
+ (a->tm_min - b->tm_min))
+ (a->tm_sec - b->tm_sec));
}
time_t
get_date(char *p)
{
struct tm *tm;
struct tm gmt, *gmt_ptr;
time_t Start;
time_t tod;
time_t nowtime;
long tzone;
memset(&gmt, 0, sizeof(gmt));
yyInput = p;
(void)time (&nowtime);
gmt_ptr = gmtime (&nowtime);
if (gmt_ptr != NULL) {
/* Copy, in case localtime and gmtime use the same buffer. */
gmt = *gmt_ptr;
}
if (! (tm = localtime (&nowtime)))
return -1;
if (gmt_ptr != NULL)
tzone = difftm (&gmt, tm) / 60;
else
/* This system doesn't understand timezones; fake it. */
tzone = 0;
if(tm->tm_isdst)
tzone += 60;
yyYear = tm->tm_year + 1900;
yyMonth = tm->tm_mon + 1;
yyDay = tm->tm_mday;
yyTimezone = tzone;
yyDSTmode = DSTmaybe;
yyHour = 0;
yyMinutes = 0;
yySeconds = 0;
yyRelSeconds = 0;
yyRelMonth = 0;
yyHaveDate = 0;
yyHaveDay = 0;
yyHaveRel = 0;
yyHaveTime = 0;
yyHaveZone = 0;
if (yyparse()
|| yyHaveTime > 1 || yyHaveZone > 1
|| yyHaveDate > 1 || yyHaveDay > 1)
return -1;
if (yyHaveDate || yyHaveTime || yyHaveDay) {
Start = Convert(yyMonth, yyDay, yyYear,
yyHour, yyMinutes, yySeconds, yyDSTmode);
if (Start < 0)
return -1;
} else {
Start = nowtime;
if (!yyHaveRel)
Start -= ((tm->tm_hour * 60L + tm->tm_min) * 60L) + tm->tm_sec;
}
Start += yyRelSeconds;
Start += RelativeMonth(Start, yyRelMonth);
if (yyHaveDay && !yyHaveDate) {
tod = RelativeDate(Start, yyDayOrdinal, yyDayNumber);
Start += tod;
}
/* Have to do *something* with a legitimate -1 so it's
* distinguishable from the error return value. (Alternately
* could set errno on error.) */
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) */