Very Computer

Hi,

I have an arbitrary date/time within an arbitrary timezone
and I want to convert this to UTC (or localtime). How do I do this?
I know about getdate(3C), but this doesn't work, if
the TZ variable is not the same as the one in the date/time
I provide. This is on Solaris 2.5.1/2.6.

Quote:> echo $TZ
MET
> cat test.c

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

int main(void) {
  struct tm *timePointer;
  struct tm time1, time2;

  putenv("DATEMSK=/tmp/getdatemask");

  timePointer = getdate("24 9 1968 12:34 CET");
  if (NULL == timePointer) {
    printf("Oops, getdate test error <%d>\n", getdate_err);
    return 1;
  }
  return 0;

Quote:}
> cat /tmp/getdatemask
%d %m %Y %H:%M %Z
> cc time.c ; ./a.out

Oops, getdate test error <7>
Exit 1

Change the timezone CET in the program to MET and the program
works just fine.

I know that I could change TZ before the invocation of getdate(),
but I need this in a multithreaded program, and thus I'd have to
synchronize access to all time/date-processing functions, which is
a lot of work.

  Guenther

P.S.: I'd be happy, if I just could find out, what the time difference
between any given time in a timezone and UTC was.

    Use mktime(), and ask it for the time in seconds for Janyary 2nd,
1970 at 0:00 local.  Than subtract 86400.  You can't use January 1st,
because east of Grenwich, it's an error (time_t being unsigned).

    If you're worried about screwing your TZ environment, fork()
and change it in the child.