Regarding time zones..

culin · 08-30-2012, 03:10 AM

Hi all ,

How can i read the timezone information from a c code ?

Eg:

time_t clock = time(NULL);
printf("Current time is %s\n", ctime(&clock));

The above code displays the calender time. But it wont show the timezone information. Where as the date command output from the command line shows it as IST. So, from where the date command is reading this information ? or how can i write a piece of C code as above to get the timezone information ? similar to date command output.

Cheers,
Naren

Snark1994 · 08-30-2012, 04:19 AM

http://www.cplusplus.com/reference/c...time/strftime/ should help. There's an example at the bottom, you just need to change the format string to get the timezone

Hope this helps,

culin · 08-31-2012, 01:34 AM

Cooooool !!! Snark1994... Thanks a lot for the info

but is there a way to tell how or from where the strftime function reads this timezone info ?

Snark1994 · 09-01-2012, 09:06 AM

From the tm struct you pass to it

As you see in the code sample, you use time() to get the current time (in seconds from the epoch, IIRC) and you pass this to localtime() which then fills the tm struct appropriately.