Create current_time function

[EduardoRSeifert]

No description provided.

[EduardoRSeifert]

should we us gmtime here instead? i was curious, i'd guess it's better to save in the user current time instead of always utc to avoid problems

[niltonvasques]

Thr ideal would be to receive the timezone as argument. And use UTC as default. Is it possible?

[EduardoRSeifert]

this is flaky, although th likelihood of failing is very low. i thought about testing it by using timediff and checking if it's 0 or 1 but i don't think that'd be better

[niltonvasques]

Could also be tested with a regex, using egrep

[EduardoRSeifert]

i see, to check if it fits the pattern, instead of checking if it displays the current_time. that is, in fact, a possibility

[EduardoRSeifert]

i decided to leave this test and add one with the regex match

[niltonvasques]

Thr ideal would be to receive the timezone as argument. And use UTC as default. Is it possible?

[niltonvasques]

Could also be tested with a regex, using egrep

[EduardoRSeifert]

@niltonvasques it is possible to set a timezone, but it'll mess with setting system environment variables and unsetting them afterwards (which is not a platform agnostic operation, there are different commands for linux and windows, for example). unless parsec is compiled with c++20, which would allow for a system agnostic approach (but would then require adding a timezone database to the build process).

here would be the base implementation (with help from mr gippity)

void set_timezone(string_type tz) {
    if (tz) {
        setenv("TZ", tz, 1); // On Windows, use _putenv_s("TZ", tz);
    } else {
        unsetenv("TZ"); // Reset to the system's default timezone
    }
    tzset(); // Apply the timezone change
}

void FunCurrentTime::Eval(ptr_val_type &ret, const ptr_val_type *a_pArg, int a_iArgc)
  {
    if (a_iArgc > 1)
      throw ParserError(ErrorContext(ecTOO_MANY_PARAMS, GetExprPos(), GetIdent()));

    string_type original_tz = getenv("TZ");
    string_type saved_tz = original_tz ? original_tz : "";
    string_type timezone = a_pArg[0]->GetString();
    set_timezone(timezone);
    std::time_t t = std::time(0);
    std::tm now = *std::localtime(&t);
    
    if (saved_tz.empty()) {
        set_timezone(nullptr); // No TZ was set initially
    } else {
        set_timezone(saved_tz.c_str());
    }

    *ret = format_time(now);
  }

[niltonvasques]

What about to establish UTC and just add or subtract depending on the arg? current_time(+3)

[EduardoRSeifert]

What about to establish UTC and just add or subtract depending on the arg? current_time(+3)

@niltonvasques and then we leave it to the user to properly determine their timezone difference to UTC? i think it's way better, and it can be offloaded to the systems using Parsec to genereate this offset, still leaving space for automation. i'll implement it and change the test to egrep and set the PR to review again!

[niltonvasques]

Yes. By doing that way we can during the setup determine the project timezone and set in the equation.

[niltonvasques]

Is missing just the timezone +1, +2....

[niltonvasques]

Suggested change

	return _T("current_time() - Returns the current time in the HH:MM:SS format.");
	return _T("current_time("+1") - Returns the current time in the HH:MM:SS format.");

[EduardoRSeifert]

oh, i thought it best to leave it as an integer param, is that a problem? so it would be current_time(1) not current_time("+1"). otherwise it would need a parser for the offset

[niltonvasques]

Ahhh! Its fine as you did! Is missing tests for that, right?

[EduardoRSeifert]

yeah! i was going to ping you when the pr was complete hehe. it is now ready

[Victorcorcos]

it is possible to set a timezone, but it'll mess with setting system environment variables and unsetting them afterwards (which is not a platform agnostic operation, there are different commands for linux and windows, for example)

Let's remember that macos would also be a problem here

[Victorcorcos]

Great job @EduardoRSeifert 👍