#line 28 "date.c-nw"
#include <config.h>
#include "equal.e"
#include "skip-sp.e"
/*
Ignoring commas and hyphens:
o-+-wday-+-+-date-month-+-+-H:M:S-zone-year-----+-garbage-o
| | | | | |
+------+ +-month-date-+ +-year-----H:M:S-zone-+
zone = o-+-zone-+------+-o
| | |
| +-diff-+
| |
+-diff--------+
| |
+-------------+
H:M:S = o-hour-":"-min-":"-sec-+---------------+-o
| |
+-"."-hundreths-+
*/
/*
This is from RFC822:
5. DATE AND TIME SPECIFICATION
5.1. SYNTAX
date-time = [ day "," ] date time ; dd mm yy
; hh:mm:ss zzz
day = "Mon" / "Tue" / "Wed" / "Thu"
/ "Fri" / "Sat" / "Sun"
date = 1*2DIGIT month 2DIGIT ; day month year
; e.g. 20 Jun 82
month = "Jan" / "Feb" / "Mar" / "Apr"
/ "May" / "Jun" / "Jul" / "Aug"
/ "Sep" / "Oct" / "Nov" / "Dec"
time = hour zone ; ANSI and Military
hour = 2DIGIT ":" 2DIGIT [":" 2DIGIT]
; 00:00:00 - 23:59:59
zone = "GMT" ; Universal Time
*/
#define SKIP(s) while (isspace(*(s)) || *(s) == ',') (s)++
static void try_weekday(char **s)
{
char *t = *s;
switch (upcase[*t]) {
case 'F': /* Fri or Feb */
t++;
if (upcase[*t] != 'R') return; /* Not a weekday */
break;
case 'M': /* Mon, Mar or May */
t++;
if (upcase[*t] != 'O') return; /* Not a weekday */
break;
case 'S': /* Sat, Sun or Sep */
t++;
if (upcase[*t] != 'A' && upcase[*t] != 'U') return; /* Not a weekday */
break;
case 'T': /* Tue or Thu */
break;
case 'W': /* Wed */
break;
default:
return; /* Not a weekday */
}
while (isalpha(*t)) t++;
SKIP(t);
*s = t;
}
static Bool try_number(char **s, int *n)
{
if (!isdigit(**s)) return FALSE;
for (*n = 0; isdigit(**s); (*s)++)
*n = 10 * *n + **s - '0';
SKIP(*s);
return TRUE;
}
static Bool try_month(char **s, int *n)
{
char *t = *s;
switch (upcase[*t]) {
case 'A': /* Apr or Aug */
*n = upcase[*(++t)] == 'P' ? 3 : 7; /* Assume Apr, resp. Aug */
break;
case 'D': *n = 11; break; /* Assume Dec */
case 'F': /* Feb or Fri */
if (upcase[*(++t)] != 'E') return FALSE; /* Error */
*n = 1; /* Assume Feb */
break;
case 'J': /* Jan, Jun or Jul */
t++;
switch (upcase[*t]) {
case 'A': *n = 0; break; /* Assume Jan */
case 'U': /* Jun or Jul */
*n = upcase[*(++t)] == 'N' ? 5 : 6; /* Assume Jun, resp. Jul */
break;
default: return FALSE; /* Error */
}
break;
case 'M': /* Mar, May or Mon */
if (upcase[*(++t)] != 'A') return FALSE; /* Error */
*n = upcase[*(++t)] == 'R' ? 2 : 4; /* Assume Mar, resp. May */
break;
case 'N': *n = 10; break; /* Assume Nov */
case 'O': *n = 9; break; /* Assume Oct */
case 'S': /* Sep, Sat or Sun */
if (upcase[*(++t)] != 'E') return FALSE; /* Error */
*n = 8;
break;
default: return FALSE; /* Error */
}
while (isalpha(*t)) t++;
SKIP(t);
*s = t;
return TRUE;
}
static void try_numeric_zone(char **s, int *zone)
{
char *t = *s;
if (*t == '-') {
t++;
if (isdigit(*t)) {
*zone = 60 * 60 * (*t - '0');
t++;
if (isdigit(*t)) {
*zone = 10 * *zone + 60 * 60 * (*t - '0');
t++;
if (isdigit(*t)) {
*zone += 10 * 60 * (*t - '0');
t++;
if (isdigit(*t)) {
*zone += 60 * (*t - '0');
t++;
}
}
}
} else
*zone = 0; /* A '-' and no digits? */
} else if (*t == '+') {
t++;
if (isdigit(*t)) {
*zone = -60 * 60 * (*t - '0');
t++;
if (isdigit(*t)) {
*zone = 10 * *zone - 60 * 60 * (*t - '0');
t++;
if (isdigit(*t)) {
*zone -= 10 * 60 * (*t - '0');
t++;
if (isdigit(*t)) {
*zone -= 60 * (*t - '0');
t++;
}
}
}
} else
*zone = 0; /* A '+' and no digits? */
} else
*zone = 0; /* No '-' and no '+' */
SKIP(t);
*s = t;
}
static void try_zone(char **s, int *zone)
{
char *t;
int diff;
if (**s == '-' || **s == '+') {
try_numeric_zone(s, zone);
} else {
t = *s;
switch (upcase[*t]) {
case 'U': *zone = 0; break; /* Assume UTC */
case 'A':
if (upcase[*(++t)] == 'S')
*zone = 4 * 60 * 60; /* Assume AST */
else
*zone = 3 * 60 * 60; /* Assume ADT */
break;
case 'B': *zone = 0; break; /* Assume BST */
case 'C':
if (upcase[*(++t)] == 'S')
*zone = 6 * 60 * 60; /* Assume CST */
else
*zone = 5 * 60 * 60; /* Assume CDT */
break;
case 'E':
if (upcase[*(++t)] == 'S')
*zone = 5 * 60 * 60; /* Assume EST */
else
*zone = 4 * 60 * 60; /* Assume EDT */
break;
case 'G': *zone = 0; break; /* Assume GMT */
case 'M':
if (upcase[*(++t)] == 'S')
*zone = 7 * 60 * 60; /* Assume MST */
else if (upcase[*t] == 'D')
*zone = 6 * 60 * 60; /* Assume MDT */
else if (upcase[*t] != 'E')
; /* Unknown */
else if (upcase[*(++t)] == 'Z')
*zone = -60 * 60; /* Assume MEZ */
else if (upcase[*t] == 'S')
*zone = -2 * 60 * 60; /* Assume MESZ */
else if (upcase[*t] != 'T')
; /* Unknown */
else if (upcase[*(++t)] == 'D')
*zone = -2 * 60 * 60; /* Assume METDST */
else
*zone = -60 * 60; /* Assume MET */
break;
case 'N':
if (upcase[*(++t)] == 'S')
*zone = 3 * 60 * 60 + 30 * 60; /* Assume NST */
else if (upcase[*(++t)] == 'D')
*zone = 2 * 60 * 60 + 30 * 60; /* Assume NDT */
else if (upcase[*t] != 'Z')
; /* Unknown */
if (upcase[*(++t)] == 'S')
*zone = -12 * 60 * 60; /* Assume NZST */
else
*zone = -13 * 60 * 60; /* Assume NZDT */
break;
case 'P':
if (upcase[*(++t)] == 'W')
*zone = 0; /* Assume PWT */
else if (upcase[*t] == 'S')
*zone = 8 * 60 * 60; /* Assume PST */
else
*zone = 7 * 60 * 60; /* Assume PDT */
break;
case 'S':
if (upcase[*(++t)] != 'A')
; /* Unknown */
else if (upcase[*(++t)] == 'S')
*zone = -2 * 60 * 60; /* Assume SAST */
else
*zone = -3 * 60 * 60; /* Assume SADT */
break;
case 'W': *zone = 0; break; /* Assume WET */
case 'Y':
if (upcase[*(++t)] == 'S')
*zone = 9 * 60 * 60; /* Assume YST */
else
*zone = 8 * 60 * 60; /* Assume YDT */
break;
default: return; /* Unknown */
}
while (isalpha(*t)) t++;
SKIP(t);
if (*t == '-' || *t == '+') {
try_numeric_zone(&t, &diff);
*zone += diff;
}
SKIP(t);
*s = t;
}
}
static Bool try_time(char **s, int *hour, int *min, int *sec)
{
char *t = *s;
if (!isdigit(*t)) return FALSE;
for (*hour = 0; isdigit(*t); t++) /* Hours */
*hour = 10 * *hour + *t - '0';
if (*hour > 24 || *t != ':') return FALSE;
t++;
if (!isdigit(*t)) return FALSE;
for (*min = 0; isdigit(*t); t++) /* Minutes */
*min = 10 * *min + *t - '0';
if (*min > 59 || *t != ':') return FALSE;
t++;
if (!isdigit(*t)) return FALSE;
for (*sec = 0; isdigit(*t); t++) /* Seconds */
*sec = 10 * *sec + *t - '0';
if (*sec > 59) return FALSE;
if (*t == '.')
do t++; while (isdigit(*t)); /* Skip hundreths */
SKIP(t);
*s = t;
return TRUE;
}
#define CENTURY_CUTOFF 70
EXPORT Bool parse_date(char *s, time_t *t)
{
struct tm h, *timeptr;
int n, zone = 0;
*t = time(NULL);
timeptr = gmtime(t);
h = *timeptr;
SKIP(s);
try_weekday(&s);
if (isdigit(*s)) {
(void) try_number(&s, &h.tm_mday);
if (*s == '-') { s++; SKIP(s); }
if (!try_month(&s, &h.tm_mon)) return FALSE;
if (*s == '-') { s++; SKIP(s); }
} else {
if (!try_month(&s, &h.tm_mon)) return FALSE;
if (!try_number(&s, &h.tm_mday)) return FALSE;
}
if (try_time(&s, &h.tm_hour, &h.tm_min, &h.tm_sec)) {
try_zone(&s, &zone);
if (!try_number(&s, &n)) return FALSE;
if (n > 1900) h.tm_year = n - 1900;
else if (n < CENTURY_CUTOFF) h.tm_year = 100 + n; /* 21st century? */
else h.tm_year = n;
} else {
if (!try_number(&s, &n)) return FALSE;
if (n > 1900) h.tm_year = n - 1900;
else if (n < CENTURY_CUTOFF) h.tm_year = 100 + n; /* 21st century? */
else h.tm_year = n;
if (!try_time(&s, &h.tm_hour, &h.tm_min, &h.tm_sec)) return FALSE;
try_zone(&s, &zone);
}
tzset();
h.tm_sec += zone; /* Convert to GMT */
h.tm_sec -= timezone; /* Convert to local time */
*t = mktime(&h); /* Compute secs since epoch */
return TRUE;
}