time_t to simple date string conversion

[Jonathan M Davis]

> On Tue, 05 Apr 2011 17:24:11 -0400, Kai Meyer <kai at unixlords.com> wrote:
> > I'm reading documentation on std.datetime, and it appears there are
> > added features that I don't have in 2.51 (Linux). Did features like
> > 'SysTime' get added after 2.51?
> > 
> > Does anybody have a one-liner to convert a time_t to a date string that
> > should work for me?
> 
> auto t = time();
> auto systime = SystemTime(unixTimeToStdTime(t)); // to system time

That's correct. However, unless you're really just getting the current time 
instead of getting the time_t from somewhere else, then you'd just do

auto systime = Clock.currTime();

The OP didn't specify where the time_t was coming from though, and if the 
time_t comes from somewhere else, then what you gave was correct.

>  from there, you have many options to create the right string.  You can
> start with just writing it (via toString):
> 
> writeln(systime);
> 
> There's also:
> 
> http://www.digitalmars.com/d/2.0/phobos/std_datetime.html#toSimpleString
> http://www.digitalmars.com/d/2.0/phobos/std_datetime.html#toISOString
> http://www.digitalmars.com/d/2.0/phobos/std_datetime.html#toISOExtendedStri
> ng
> 
> and doing it directly:
> 
> writefln("%s/%s/%s", t.month, t.day, t.year);
> 
> Don't see a way to print the month in text format, but maybe I'm
> overlooking it.

toSimpleString (which toString calls) does give the short version of the month 
in it, but during the review process, a number of the folks reviewing  it were 
against putting code in there relating to printing the month out as a name 
rather than a number, because that gets it to dealing locales. The result is 
that the only stuff in std.datetime that does anything with the month's name 
as a string is toSimpleString (and therefore toString) and fromSimpleString on 
SysTime, Date, and DateTime. Everything else is numbers (though the Month enum 
does use the 3-letter English abbreviations for the names of its enum values).

I wouldn't have minded having English-specific stuff in there with locales 
being dealt with elsewhere, but it essentially got pushed out entirely, so 
there's next to no English-specific stuff in there, and it will _all_ be in 
locale stuff, if we ever _do_ any locale stuff.

- Jonathan M Davis