Re: [RFC PATCH v2] Add 'human' date format

[Andrei Rybak <rybak.a.v@gmail.com>]

On 2018-07-08 00:02, Linus Torvalds wrote:
> diff --git a/date.c b/date.c
> index 49f943e25..4486c028a 100644
> --- a/date.c
> +++ b/date.c
> @@ -77,22 +77,16 @@ static struct tm *time_to_tm_local(timestamp_t time)
>  }
>
>  /*
> - * What value of "tz" was in effect back then at "time" in the
> - * local timezone?
> + * Fill in the localtime 'struct tm' for the supplied time,
> + * and return the local tz.
>   */
> -static int local_tzoffset(timestamp_t time)
> +static int local_time_tzoffset(time_t t, struct tm *tm)
>  {
> -     time_t t, t_local;
> -     struct tm tm;
> +     time_t t_local;
>       int offset, eastwest;
>
> -     if (date_overflows(time))
> -             die("Timestamp too large for this system: %"PRItime, time);
> -
> -     t = (time_t)time;
> -     localtime_r(&t, &tm);
> -     t_local = tm_to_time_t(&tm);
> -
> +     localtime_r(&t, tm);
> +     t_local = tm_to_time_t(tm);
>       if (t_local == -1)
>               return 0; /* error; just use +0000 */
>       if (t_local < t) {
> @@ -107,6 +101,20 @@ static int local_tzoffset(timestamp_t time)
>       return offset * eastwest;
>  }
>

[...]

> +
>  const char *show_date(timestamp_t time, int tz, const struct date_mode *mode)
>  {
>       struct tm *tm;
> +     struct tm human_tm = { 0 };
> +     int human_tz = -1;

Is -1 an OK initial value for timezone if local_time_tzoffset returns
negative values as well? It looks like it doesn't matter for from functional

>       static struct strbuf timebuf = STRBUF_INIT;
>
>       if (mode->type == DATE_UNIX) {
> @@ -202,6 +281,15 @@ const char *show_date(timestamp_t time, int tz, const struct date_mode *mode)
>               return timebuf.buf;
>       }
>
> +     if (mode->type == DATE_HUMAN) {
> +             struct timeval now;
> +
> +             gettimeofday(&now, NULL);
> +
> +             /* Fill in the data for "current time" in human_tz and human_tm */
> +             human_tz = local_time_tzoffset(now.tv_sec, &human_tm);
> +     }
> +
>       if (mode->local)
>               tz = local_tzoffset(time);
>

--
Best regards, Andrei Rybak