hello, i’m new to programming in i’m trying to solve this exercise in C, basically it’s the amount of passed hours between the start of a game and it’s end, if the game started at 16 and ended at 2 the result is a game with 10 hours(in different days) i know i can to it more manually, but i wanted to somehow use the <time.h> to learn how to use a header etc, can someone help me?, thank you all
Okay, I’ve read up on this a bit an you raise some valid points.
For whatever reason, posix has decided that
CLOCKS_PER_SECmust be exactly 1000000 on every system that wants to comply. That doesn’t leave much room on a 32-bit system for maximum clock duration. It will wrap around well before the 10 hours the OP was giving by example.The other is I gather on some systems,
clock()may be measuring the uptime of a particular process, which is not necessarily the same as real world time in multicore environments. (Fwiw I’m on a Mac where I don’t think it works that way? You would need some special apis to get that kind of info.)I’m trying to think of the last time I programmed straight C and used
time.hand the like. It was probably in developing scientific instrumentation? iirc the clock in that case was keyed to the VBL refresh of the display, meaningCLOCKS_PER_SECwould have been something like 60 Hz. And I doubttime()would have yielded any useful value. I wonder what the OP’s use case is?Most of my hobby programming is in ANSI C and C99, so I’m unfortunately far too aware of the weird and counter-intuitive things the C and POSIX standards say. :P
clock()is fantastic for sub-second timings, such as deltatimes in games, or peripheral synchronization, which matches the use case you mention very well. I recommendedtime()over it as OP’s use case is for calculating the amount of hours a user has had their software open, and unix timestamps are the perfect mechanism to do that in my opinion.