freebsd-dev/gnu/usr.bin/rcs/lib/partime.c
1997-02-22 15:48:31 +00:00

702 lines
19 KiB
C

/* Parse a string, yielding a struct partime that describes it. */
/* Copyright 1993, 1994, 1995 Paul Eggert
Distributed under license by the Free Software Foundation, Inc.
This file is part of RCS.
RCS is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
RCS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with RCS; see the file COPYING.
If not, write to the Free Software Foundation,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
Report problems and direct all questions to:
rcs-bugs@cs.purdue.edu
*/
#if has_conf_h
# include "conf.h"
#else
# ifdef __STDC__
# define P(x) x
# else
# define const
# define P(x) ()
# endif
# include <limits.h>
# include <time.h>
#endif
#include <ctype.h>
#undef isdigit
#define isdigit(c) (((unsigned)(c)-'0') <= 9) /* faster than stock */
#include "partime.h"
char const partimeId[]
= "$Id$";
/* Lookup tables for names of months, weekdays, time zones. */
#define NAME_LENGTH_MAXIMUM 4
struct name_val {
char name[NAME_LENGTH_MAXIMUM];
int val;
};
static char const *parse_decimal P((char const*,int,int,int,int,int*,int*));
static char const *parse_fixed P((char const*,int,int*));
static char const *parse_pattern_letter P((char const*,int,struct partime*));
static char const *parse_prefix P((char const*,struct partime*,int*));
static char const *parse_ranged P((char const*,int,int,int,int*));
static int lookup P((char const*,struct name_val const[]));
static int merge_partime P((struct partime*, struct partime const*));
static void undefine P((struct partime*));
static struct name_val const month_names[] = {
{"jan",0}, {"feb",1}, {"mar",2}, {"apr",3}, {"may",4}, {"jun",5},
{"jul",6}, {"aug",7}, {"sep",8}, {"oct",9}, {"nov",10}, {"dec",11},
{"", TM_UNDEFINED}
};
static struct name_val const weekday_names[] = {
{"sun",0}, {"mon",1}, {"tue",2}, {"wed",3}, {"thu",4}, {"fri",5}, {"sat",6},
{"", TM_UNDEFINED}
};
#define hr60nonnegative(t) ((t)/100 * 60 + (t)%100)
#define hr60(t) ((t)<0 ? -hr60nonnegative(-(t)) : hr60nonnegative(t))
#define zs(t,s) {s, hr60(t)}
#define zd(t,s,d) zs(t, s), zs((t)+100, d)
static struct name_val const zone_names[] = {
zs(-1000, "hst"), /* Hawaii */
zd(-1000,"hast","hadt"),/* Hawaii-Aleutian */
zd(- 900,"akst","akdt"),/* Alaska */
zd(- 800, "pst", "pdt"),/* Pacific */
zd(- 700, "mst", "mdt"),/* Mountain */
zd(- 600, "cst", "cdt"),/* Central */
zd(- 500, "est", "edt"),/* Eastern */
zd(- 400, "ast", "adt"),/* Atlantic */
zd(- 330, "nst", "ndt"),/* Newfoundland */
zs( 000, "utc"), /* Coordinated Universal */
zs( 000, "cut"), /* " */
zs( 000, "ut"), /* Universal */
zs( 000, "z"), /* Zulu (required by ISO 8601) */
zd( 000, "gmt", "bst"),/* Greenwich Mean, British Summer */
zs( 000, "wet"), /* Western Europe */
zs( 100, "met"), /* Middle Europe */
zs( 100, "cet"), /* Central Europe */
zs( 200, "eet"), /* Eastern Europe */
zs( 530, "ist"), /* India */
zd( 900, "jst", "jdt"),/* Japan */
zd( 900, "kst", "kdt"),/* Korea */
zd( 1200,"nzst","nzdt"),/* New Zealand */
{ "lt", 1 },
#if 0
/* The following names are duplicates or are not well attested. */
zs(-1100, "sst"), /* Samoa */
zs(-1000, "tht"), /* Tahiti */
zs(- 930, "mqt"), /* Marquesas */
zs(- 900, "gbt"), /* Gambier */
zd(- 900, "yst", "ydt"),/* Yukon - name is no longer used */
zs(- 830, "pit"), /* Pitcairn */
zd(- 500, "cst", "cdt"),/* Cuba */
zd(- 500, "ast", "adt"),/* Acre */
zd(- 400, "wst", "wdt"),/* Western Brazil */
zd(- 400, "ast", "adt"),/* Andes */
zd(- 400, "cst", "cdt"),/* Chile */
zs(- 300, "wgt"), /* Western Greenland */
zd(- 300, "est", "edt"),/* Eastern South America */
zs(- 300, "mgt"), /* Middle Greenland */
zd(- 200, "fst", "fdt"),/* Fernando de Noronha */
zs(- 100, "egt"), /* Eastern Greenland */
zs(- 100, "aat"), /* Atlantic Africa */
zs(- 100, "act"), /* Azores and Canaries */
zs( 000, "wat"), /* West Africa */
zs( 100, "cat"), /* Central Africa */
zd( 100, "mez","mesz"),/* Mittel-Europaeische Zeit */
zs( 200, "sat"), /* South Africa */
zd( 200, "ist", "idt"),/* Israel */
zs( 300, "eat"), /* East Africa */
zd( 300, "ast", "adt"),/* Arabia */
zd( 300, "msk", "msd"),/* Moscow */
zd( 330, "ist", "idt"),/* Iran */
zs( 400, "gst"), /* Gulf */
zs( 400, "smt"), /* Seychelles & Mascarene */
zd( 400, "esk", "esd"),/* Yekaterinburg */
zd( 400, "bsk", "bsd"),/* Baku */
zs( 430, "aft"), /* Afghanistan */
zd( 500, "osk", "osd"),/* Omsk */
zs( 500, "pkt"), /* Pakistan */
zd( 500, "tsk", "tsd"),/* Tashkent */
zs( 545, "npt"), /* Nepal */
zs( 600, "bgt"), /* Bangladesh */
zd( 600, "nsk", "nsd"),/* Novosibirsk */
zs( 630, "bmt"), /* Burma */
zs( 630, "cct"), /* Cocos */
zs( 700, "ict"), /* Indochina */
zs( 700, "jvt"), /* Java */
zd( 700, "isk", "isd"),/* Irkutsk */
zs( 800, "hkt"), /* Hong Kong */
zs( 800, "pst"), /* Philippines */
zs( 800, "sgt"), /* Singapore */
zd( 800, "cst", "cdt"),/* China */
zd( 800, "ust", "udt"),/* Ulan Bator */
zd( 800, "wst", "wst"),/* Western Australia */
zd( 800, "ysk", "ysd"),/* Yakutsk */
zs( 900, "blt"), /* Belau */
zs( 900, "mlt"), /* Moluccas */
zd( 900, "vsk", "vsd"),/* Vladivostok */
zd( 930, "cst", "cst"),/* Central Australia */
zs( 1000, "gst"), /* Guam */
zd( 1000, "gsk", "gsd"),/* Magadan */
zd( 1000, "est", "est"),/* Eastern Australia */
zd( 1100,"lhst","lhst"),/* Lord Howe */
zd( 1100, "psk", "psd"),/* Petropavlovsk-Kamchatski */
zs( 1100,"ncst"), /* New Caledonia */
zs( 1130,"nrft"), /* Norfolk */
zd( 1200, "ask", "asd"),/* Anadyr */
zs( 1245,"nz-chat"), /* Chatham */
zs( 1300, "tgt"), /* Tongatapu */
#endif
{"", -1}
};
static int
lookup (s, table)
char const *s;
struct name_val const table[];
/* Look for a prefix of S in TABLE, returning val for first matching entry. */
{
int j;
char buf[NAME_LENGTH_MAXIMUM];
for (j = 0; j < NAME_LENGTH_MAXIMUM; j++) {
unsigned char c = *s++;
buf[j] = isupper (c) ? tolower (c) : c;
if (!isalpha (c))
break;
}
for (; table[0].name[0]; table++)
for (j = 0; buf[j] == table[0].name[j]; )
if (++j == NAME_LENGTH_MAXIMUM || !table[0].name[j])
goto done;
done:
return table[0].val;
}
static void
undefine (t) struct partime *t;
/* Set *T to ``undefined'' values. */
{
t->tm.tm_sec = t->tm.tm_min = t->tm.tm_hour = t->tm.tm_mday = t->tm.tm_mon
= t->tm.tm_year = t->tm.tm_wday = t->tm.tm_yday
= t->ymodulus = t->yweek
= TM_UNDEFINED;
t->zone = TM_UNDEFINED_ZONE;
}
/*
* Array of patterns to look for in a date string.
* Order is important: we look for the first matching pattern
* whose values do not contradict values that we already know about.
* See `parse_pattern_letter' below for the meaning of the pattern codes.
*/
static char const * const patterns[] = {
/*
* These traditional patterns must come first,
* to prevent an ISO 8601 format from misinterpreting their prefixes.
*/
"E_n_y", "x", /* RFC 822 */
"E_n", "n_E", "n", "t:m:s_A", "t:m_A", "t_A", /* traditional */
"y/N/D$", /* traditional RCS */
/* ISO 8601:1988 formats, generalized a bit. */
"y-N-D$", "4ND$", "Y-N$",
"RND$", "-R=N$", "-R$", "--N=D$", "N=DT",
"--N$", "---D$", "DT",
"Y-d$", "4d$", "R=d$", "-d$", "dT",
"y-W-X", "yWX", "y=W",
"-r-W-X", "r-W-XT", "-rWX", "rWXT", "-W=X", "W=XT", "-W",
"-w-X", "w-XT", "---X$", "XT", "4$",
"T",
"h:m:s$", "hms$", "h:m$", "hm$", "h$", "-m:s$", "-ms$", "-m$", "--s$",
"Y", "Z",
0
};
static char const *
parse_prefix (str, t, pi) char const *str; struct partime *t; int *pi;
/*
* Parse an initial prefix of STR, setting *T accordingly.
* Return the first character after the prefix, or 0 if it couldn't be parsed.
* Start with pattern *PI; if success, set *PI to the next pattern to try.
* Set *PI to -1 if we know there are no more patterns to try;
* if *PI is initially negative, give up immediately.
*/
{
int i = *pi;
char const *pat;
unsigned char c;
if (i < 0)
return 0;
/* Remove initial noise. */
while (!isalnum (c = *str) && c != '-' && c != '+') {
if (!c) {
undefine (t);
*pi = -1;
return str;
}
str++;
}
/* Try a pattern until one succeeds. */
while ((pat = patterns[i++]) != 0) {
char const *s = str;
undefine (t);
do {
if (!(c = *pat++)) {
*pi = i;
return s;
}
} while ((s = parse_pattern_letter (s, c, t)) != 0);
}
return 0;
}
static char const *
parse_fixed (s, digits, res) char const *s; int digits, *res;
/*
* Parse an initial prefix of S of length DIGITS; it must be a number.
* Store the parsed number into *RES.
* Return the first character after the prefix, or 0 if it couldn't be parsed.
*/
{
int n = 0;
char const *lim = s + digits;
while (s < lim) {
unsigned d = *s++ - '0';
if (9 < d)
return 0;
n = 10*n + d;
}
*res = n;
return s;
}
static char const *
parse_ranged (s, digits, lo, hi, res) char const *s; int digits, lo, hi, *res;
/*
* Parse an initial prefix of S of length DIGITS;
* it must be a number in the range LO through HI.
* Store the parsed number into *RES.
* Return the first character after the prefix, or 0 if it couldn't be parsed.
*/
{
s = parse_fixed (s, digits, res);
return s && lo<=*res && *res<=hi ? s : 0;
}
static char const *
parse_decimal (s, digits, lo, hi, resolution, res, fres)
char const *s;
int digits, lo, hi, resolution, *res, *fres;
/*
* Parse an initial prefix of S of length DIGITS;
* it must be a number in the range LO through HI
* and it may be followed by a fraction that is to be computed using RESOLUTION.
* Store the parsed number into *RES; store the fraction times RESOLUTION,
* rounded to the nearest integer, into *FRES.
* Return the first character after the prefix, or 0 if it couldn't be parsed.
*/
{
s = parse_fixed (s, digits, res);
if (s && lo<=*res && *res<=hi) {
int f = 0;
if ((s[0]==',' || s[0]=='.') && isdigit ((unsigned char) s[1])) {
char const *s1 = ++s;
int num10 = 0, denom10 = 10, product;
while (isdigit ((unsigned char) *++s))
denom10 *= 10;
s = parse_fixed (s1, s - s1, &num10);
product = num10*resolution;
f = (product + (denom10>>1)) / denom10;
f -= f & (product%denom10 == denom10>>1); /* round to even */
if (f < 0 || product/resolution != num10)
return 0; /* overflow */
}
*fres = f;
return s;
}
return 0;
}
char *
parzone (s, zone) char const *s; long *zone;
/*
* Parse an initial prefix of S; it must denote a time zone.
* Set *ZONE to the number of seconds east of GMT,
* or to TM_LOCAL_ZONE if it is the local time zone.
* Return the first character after the prefix, or 0 if it couldn't be parsed.
*/
{
char sign;
int hh, mm, ss;
int minutesEastOfUTC;
long offset, z;
/*
* The formats are LT, n, n DST, nDST, no, o
* where n is a time zone name
* and o is a time zone offset of the form [-+]hh[:mm[:ss]].
*/
switch (*s) {
case '-': case '+':
z = 0;
break;
default:
minutesEastOfUTC = lookup (s, zone_names);
if (minutesEastOfUTC == -1)
return 0;
/* Don't bother to check rest of spelling. */
while (isalpha ((unsigned char) *s))
s++;
/* Don't modify LT. */
if (minutesEastOfUTC == 1) {
*zone = TM_LOCAL_ZONE;
return (char *) s;
}
z = minutesEastOfUTC * 60L;
/* Look for trailing " DST". */
if (
(s[-1]=='T' || s[-1]=='t') &&
(s[-2]=='S' || s[-2]=='s') &&
(s[-3]=='D' || s[-3]=='t')
)
goto trailing_dst;
while (isspace ((unsigned char) *s))
s++;
if (
(s[0]=='D' || s[0]=='d') &&
(s[1]=='S' || s[1]=='s') &&
(s[2]=='T' || s[2]=='t')
) {
s += 3;
trailing_dst:
*zone = z + 60*60;
return (char *) s;
}
switch (*s) {
case '-': case '+': break;
default: return (char *) s;
}
}
sign = *s++;
if (!(s = parse_ranged (s, 2, 0, 23, &hh)))
return 0;
mm = ss = 0;
if (*s == ':')
s++;
if (isdigit ((unsigned char) *s)) {
if (!(s = parse_ranged (s, 2, 0, 59, &mm)))
return 0;
if (*s==':' && s[-3]==':' && isdigit ((unsigned char) s[1])) {
if (!(s = parse_ranged (s + 1, 2, 0, 59, &ss)))
return 0;
}
}
if (isdigit ((unsigned char) *s))
return 0;
offset = (hh*60 + mm)*60L + ss;
*zone = z + (sign=='-' ? -offset : offset);
/*
* ?? Are fractions allowed here?
* If so, they're not implemented.
*/
return (char *) s;
}
static char const *
parse_pattern_letter (s, c, t) char const *s; int c; struct partime *t;
/*
* Parse an initial prefix of S, matching the pattern whose code is C.
* Set *T accordingly.
* Return the first character after the prefix, or 0 if it couldn't be parsed.
*/
{
switch (c) {
case '$': /* The next character must be a non-digit. */
if (isdigit ((unsigned char) *s))
return 0;
break;
case '-': case '/': case ':':
/* These characters stand for themselves. */
if (*s++ != c)
return 0;
break;
case '4': /* 4-digit year */
s = parse_fixed (s, 4, &t->tm.tm_year);
break;
case '=': /* optional '-' */
s += *s == '-';
break;
case 'A': /* AM or PM */
/*
* This matches the regular expression [AaPp][Mm]?.
* It must not be followed by a letter or digit;
* otherwise it would match prefixes of strings like "PST".
*/
switch (*s++) {
case 'A': case 'a':
if (t->tm.tm_hour == 12)
t->tm.tm_hour = 0;
break;
case 'P': case 'p':
if (t->tm.tm_hour != 12)
t->tm.tm_hour += 12;
break;
default: return 0;
}
switch (*s) {
case 'M': case 'm': s++; break;
}
if (isalnum (*s))
return 0;
break;
case 'D': /* day of month [01-31] */
s = parse_ranged (s, 2, 1, 31, &t->tm.tm_mday);
break;
case 'd': /* day of year [001-366] */
s = parse_ranged (s, 3, 1, 366, &t->tm.tm_yday);
t->tm.tm_yday--;
break;
case 'E': /* extended day of month [1-9, 01-31] */
s = parse_ranged (s, (
isdigit ((unsigned char) s[0]) &&
isdigit ((unsigned char) s[1])
) + 1, 1, 31, &t->tm.tm_mday);
break;
case 'h': /* hour [00-23 followed by optional fraction] */
{
int frac;
s = parse_decimal (s, 2, 0, 23, 60*60, &t->tm.tm_hour, &frac);
t->tm.tm_min = frac / 60;
t->tm.tm_sec = frac % 60;
}
break;
case 'm': /* minute [00-59 followed by optional fraction] */
s = parse_decimal (s, 2, 0, 59, 60, &t->tm.tm_min, &t->tm.tm_sec);
break;
case 'n': /* month name [e.g. "Jan"] */
if (!TM_DEFINED (t->tm.tm_mon = lookup (s, month_names)))
return 0;
/* Don't bother to check rest of spelling. */
while (isalpha ((unsigned char) *s))
s++;
break;
case 'N': /* month [01-12] */
s = parse_ranged (s, 2, 1, 12, &t->tm.tm_mon);
t->tm.tm_mon--;
break;
case 'r': /* year % 10 (remainder in origin-0 decade) [0-9] */
s = parse_fixed (s, 1, &t->tm.tm_year);
t->ymodulus = 10;
break;
case_R:
case 'R': /* year % 100 (remainder in origin-0 century) [00-99] */
s = parse_fixed (s, 2, &t->tm.tm_year);
t->ymodulus = 100;
break;
case 's': /* second [00-60 followed by optional fraction] */
{
int frac;
s = parse_decimal (s, 2, 0, 60, 1, &t->tm.tm_sec, &frac);
t->tm.tm_sec += frac;
}
break;
case 'T': /* 'T' or 't' */
switch (*s++) {
case 'T': case 't': break;
default: return 0;
}
break;
case 't': /* traditional hour [1-9 or 01-12] */
s = parse_ranged (s, (
isdigit ((unsigned char) s[0]) && isdigit ((unsigned char) s[1])
) + 1, 1, 12, &t->tm.tm_hour);
break;
case 'w': /* 'W' or 'w' only (stands for current week) */
switch (*s++) {
case 'W': case 'w': break;
default: return 0;
}
break;
case 'W': /* 'W' or 'w', followed by a week of year [00-53] */
switch (*s++) {
case 'W': case 'w': break;
default: return 0;
}
s = parse_ranged (s, 2, 0, 53, &t->yweek);
break;
case 'X': /* weekday (1=Mon ... 7=Sun) [1-7] */
s = parse_ranged (s, 1, 1, 7, &t->tm.tm_wday);
t->tm.tm_wday--;
break;
case 'x': /* weekday name [e.g. "Sun"] */
if (!TM_DEFINED (t->tm.tm_wday = lookup (s, weekday_names)))
return 0;
/* Don't bother to check rest of spelling. */
while (isalpha ((unsigned char) *s))
s++;
break;
case 'y': /* either R or Y */
if (
isdigit ((unsigned char) s[0]) &&
isdigit ((unsigned char) s[1]) &&
!isdigit ((unsigned char) s[2])
)
goto case_R;
/* fall into */
case 'Y': /* year in full [4 or more digits] */
{
int len = 0;
while (isdigit ((unsigned char) s[len]))
len++;
if (len < 4)
return 0;
s = parse_fixed (s, len, &t->tm.tm_year);
}
break;
case 'Z': /* time zone */
s = parzone (s, &t->zone);
break;
case '_': /* possibly empty sequence of non-alphanumerics */
while (!isalnum (*s) && *s)
s++;
break;
default: /* bad pattern */
return 0;
}
return s;
}
static int
merge_partime (t, u) struct partime *t; struct partime const *u;
/*
* If there is no conflict, merge into *T the additional information in *U
* and return 0. Otherwise do nothing and return -1.
*/
{
# define conflict(a,b) ((a) != (b) && TM_DEFINED (a) && TM_DEFINED (b))
if (
conflict (t->tm.tm_sec, u->tm.tm_sec) ||
conflict (t->tm.tm_min, u->tm.tm_min) ||
conflict (t->tm.tm_hour, u->tm.tm_hour) ||
conflict (t->tm.tm_mday, u->tm.tm_mday) ||
conflict (t->tm.tm_mon, u->tm.tm_mon) ||
conflict (t->tm.tm_year, u->tm.tm_year) ||
conflict (t->tm.tm_wday, u->tm.tm_yday) ||
conflict (t->ymodulus, u->ymodulus) ||
conflict (t->yweek, u->yweek) ||
(
t->zone != u->zone &&
t->zone != TM_UNDEFINED_ZONE &&
u->zone != TM_UNDEFINED_ZONE
)
)
return -1;
# undef conflict
# define merge_(a,b) if (TM_DEFINED (b)) (a) = (b);
merge_ (t->tm.tm_sec, u->tm.tm_sec)
merge_ (t->tm.tm_min, u->tm.tm_min)
merge_ (t->tm.tm_hour, u->tm.tm_hour)
merge_ (t->tm.tm_mday, u->tm.tm_mday)
merge_ (t->tm.tm_mon, u->tm.tm_mon)
merge_ (t->tm.tm_year, u->tm.tm_year)
merge_ (t->tm.tm_wday, u->tm.tm_yday)
merge_ (t->ymodulus, u->ymodulus)
merge_ (t->yweek, u->yweek)
# undef merge_
if (u->zone != TM_UNDEFINED_ZONE) t->zone = u->zone;
return 0;
}
char *
partime (s, t) char const *s; struct partime *t;
/*
* Parse a date/time prefix of S, putting the parsed result into *T.
* Return the first character after the prefix.
* The prefix may contain no useful information;
* in that case, *T will contain only undefined values.
*/
{
struct partime p;
undefine (t);
while (*s) {
int i = 0;
char const *s1;
do {
if (!(s1 = parse_prefix (s, &p, &i)))
return (char *) s;
} while (merge_partime (t, &p) != 0);
s = s1;
}
return (char *) s;
}