using date function in unix

Question

how can I determine machine time in seconds on unix O/S? (i can't use 'date +%s', it's not POSIX).
what functions exist for date and epoch time in second?
by using date "+%format" how can i subtract 1-2 hour from present hour?

Regards

Looks like a duplicate of stackoverflow.com/questions/2445198 — Jens
– Jens, Commented Sep 1, 2011 at 8:28

icktoofay · Accepted Answer · 2011-05-09 06:20:23Z

0

time_t the_time=time(NULL);
// the_time now contains the number of seconds since the epoch

To get a time in the past, just subtract the number of seconds. Since there are 3600 seconds in an hour, to go an hour back, just subtract 3600.

answered May 9, 2011 at 6:20

icktoofay

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4 Comments

it can be use in shell script? it recieve value?

Sorry, I assumed you were using C. I don't see what's wrong with date +%s; I'm using Mac OS X and it works here.

A little searching shows that Solaris is a little odd in this respect. This may be helpful, but I'm not sure: solarisjedi.blogspot.com/2006/06/…

Oh, and I forgot to say: you may need to use platform detection. It sucks, but so does Solaris not supporting date +%s.