date.c: allow even more varied time formats

(and some added checks for truly non-sensical stuff)
This commit is contained in:
Linus Torvalds 2005-05-01 11:48:34 -07:00
parent e2a669bb2e
commit 198b0fb635

206
date.c
View File

@ -157,75 +157,164 @@ static int match_alpha(const char *date, struct tm *tm, int *offset)
return 0;
}
static int match_digit(char *date, struct tm *tm, int *offset)
static int is_date(int year, int month, int day, struct tm *tm)
{
char *end, c;
unsigned long num, num2, num3;
num = strtoul(date, &end, 10);
/* Time? num:num[:num] */
if (num < 24 && end[0] == ':' && isdigit(end[1])) {
tm->tm_hour = num;
num = strtoul(end+1, &end, 10);
if (num < 60) {
tm->tm_min = num;
if (end[0] == ':' && isdigit(end[1])) {
num = strtoul(end+1, &end, 10);
if (num < 61)
tm->tm_sec = num;
}
if (month > 0 && month < 13 && day > 0 && day < 32) {
if (year == -1) {
tm->tm_mon = month-1;
tm->tm_mday = day;
return 1;
}
return end - date;
if (year >= 1970 && year < 2100) {
year -= 1900;
} else if (year > 70 && year < 100) {
/* ok */
} else if (year < 38) {
year += 100;
} else
return 0;
tm->tm_mon = month-1;
tm->tm_mday = day;
tm->tm_year = year;
return 1;
}
return 0;
}
/* Year? Day of month? Numeric date-string?*/
c = *end;
static int match_multi_number(unsigned long num, char c, char *date, char *end, struct tm *tm)
{
long num2, num3;
num2 = strtol(end+1, &end, 10);
num3 = -1;
if (*end == c && isdigit(end[1]))
num3 = strtol(end+1, &end, 10);
/* Time? Date? */
switch (c) {
default:
if (num > 0 && num < 32) {
tm->tm_mday = num;
case ':':
if (num3 < 0)
num3 = 0;
if (num < 25 && num2 >= 0 && num2 < 60 && num3 >= 0 && num3 <= 60) {
tm->tm_hour = num;
tm->tm_min = num2;
tm->tm_sec = num3;
break;
}
if (num > 1900) {
tm->tm_year = num - 1900;
break;
}
if (num > 70) {
tm->tm_year = num;
break;
}
break;
return 0;
case '-':
case '/':
if (num && num < 32 && isdigit(end[1])) {
num2 = strtoul(end+1, &end, 10);
if (!num2 || num2 > 31)
if (num > 70) {
/* yyyy-mm-dd? */
if (is_date(num, num2, num3, tm))
break;
if (num > 12) {
if (num2 > 12)
break;
num3 = num;
num = num2;
num2 = num3;
}
tm->tm_mon = num - 1;
tm->tm_mday = num2;
if (*end == c && isdigit(end[1])) {
num3 = strtoul(end+1, &end, 10);
if (num3 > 1900)
num3 -= 1900;
else if (num3 < 38)
num3 += 100;
tm->tm_year = num3;
}
/* yyyy-dd-mm? */
if (is_date(num, num3, num2, tm))
break;
}
/* mm/dd/yy ? */
if (is_date(num3, num2, num, tm))
break;
/* dd/mm/yy ? */
if (is_date(num3, num, num2, tm))
break;
return 0;
}
return end - date;
}
/*
* We've seen a digit. Time? Year? Date?
*/
static int match_digit(char *date, struct tm *tm, int *offset)
{
int n;
char *end;
unsigned long num;
num = strtoul(date, &end, 10);
/*
* Seconds since 1970? We trigger on that for anything after Jan 1, 2000
*/
if (num > 946684800) {
time_t time = num;
if (gmtime_r(&time, tm))
return end - date;
}
/*
* Check for special formats: num[:-/]num[same]num
*/
switch (*end) {
case ':':
case '/':
case '-':
if (isdigit(end[1])) {
int match = match_multi_number(num, *end, date, end, tm);
if (match)
return match;
}
}
/*
* None of the special formats? Try to guess what
* the number meant. We use the number of digits
* to make a more educated guess..
*/
n = 0;
do {
n++;
} while (isdigit(date[n]));
/* Four-digit year or a timezone? */
if (n == 4) {
if (num <= 1200 && *offset == -1) {
unsigned int minutes = num % 100;
unsigned int hours = num / 100;
*offset = hours*60 + minutes;
} else if (num > 1900 && num < 2100)
tm->tm_year = num - 1900;
return n;
}
/*
* NOTE! We will give precedence to day-of-month over month or
* year numebers in the 1-12 range. So 05 is always "mday 5",
* unless we already have a mday..
*
* IOW, 01 Apr 05 parses as "April 1st, 2005".
*/
if (num > 0 && num < 32 && tm->tm_mday < 0) {
tm->tm_mday = num;
return n;
}
/* Two-digit year? */
if (n == 2 && tm->tm_year < 0) {
if (num < 10 && tm->tm_mday >= 0) {
tm->tm_year = num + 100;
return n;
}
if (num >= 70) {
tm->tm_year = num;
return n;
}
}
if (num > 0 && num < 32) {
tm->tm_mday = num;
} else if (num > 1900) {
tm->tm_year = num - 1900;
} else if (num > 70) {
tm->tm_year = num;
} else if (num > 0 && num < 13) {
tm->tm_mon = num-1;
}
return end - date;
return n;
}
static int match_tz(char *date, int *offp)
@ -233,10 +322,19 @@ static int match_tz(char *date, int *offp)
char *end;
int offset = strtoul(date+1, &end, 10);
int min, hour;
int n = end - date - 1;
min = offset % 100;
hour = offset / 100;
/*
* Don't accept any random crap.. At least 3 digits, and
* a valid minute. We might want to check that the minutes
* are divisible by 30 or something too.
*/
if (min >= 60 || n < 3)
return 0;
offset = hour*60+min;
if (*date == '-')
offset = -offset;