Hi, Guys

I'm converting some code that uses the Mysql/Mariadb C api from
text queries to prepared statements, and would like my public
interfaces to use struct tm (Unix "broken-down" time) instead of
MYSQL_TIME.

ISTM that in all the years of the Mysql C API, /someone/ probably
has tackled such an interface. So, instead of "re-inventing the
wheel", I thought that I'd ask around: can you direct me to
or provide the source code for a proper MYSQL_TIME to Unix struct tm
conversion routine?

FWIW, for testing purposes, I wrote my own naive conversion
functions: timeMtoU() (which converts MYSQL_TIME to struct tm),
and timeUtoM() (which converts struct tm to MYSQL_TIME)

I include the source code for these two functions, in case
someone can suggest improvements or bugfixes.

struct tm *timeMtoU(MYSQL_TIME *mtime, struct tm *utime)
{
/*
** Note:
** MYSQL_TIME year is always a positive value
** ranging from year 1000AD to year 9999AD, or
** year 0000 for special cases.
**
** MYSQL_TIME month ranges from 1 (January) to 12 (December),
** while struct tm tm_mon ranges from 0 (January) to 11 (December)
** Subtract 1 from month to get tm_mon
*/
memset(utime,0,sizeof *utime);

utime->tm_sec = mtime->second;
utime->tm_min = mtime->minute;
utime->tm_hour = mtime->hour;
utime->tm_mday = mtime->day;
utime->tm_mon = mtime->month - 1;
utime->tm_year = mtime->year - 1900;

utime->tm_isdst = -1; /* let time functions figure it out */

/*
** NB: we naively leave tm_wday and tm_yday set to 0.
** If the caller /requires/ a valid tm_wday and/or tm_yday
** it's going to have to manipulate the struct tm itself
*/

return utime;
}

MYSQL_TIME *timeUtoM(struct tm *utime, MYSQL_TIME *mtime)
{
/*
** NOTE:
** struct tm tm_year is number of years (+ve or -ve) from
** the year 1900. So, the year 1899 is tm_year = -1,
** and year 1901 is tm_year = 1.
**
** struct tm tm_mon ranges from 0 (January) to 11 (December)
** while MYSQL_TIME month ranges from 1 (January) to 12 (December)
** Add 1 to tm_mon to get month
*/
memset(mtime,0,sizeof *mtime);

mtime->year = 1900 + utime->tm_year; /* error before 1000AD */
mtime->month = utime->tm_mon + 1;
mtime->day = utime->tm_mday;
mtime->hour = utime->tm_hour;
mtime->minute = utime->tm_min;
mtime->second = utime->tm_sec;
mtime->neg = 0; /* never negative time */
mtime->second_part = 0;

return mtime;
}

Thanks in advance
--
Lew Pitcher
"In Skills We Trust"