[pacman-dev] [PATCH] Reformatting log timestamp to include time-zone

[Allan McRae]

On 5/3/19 7:46 am, Florian Wehner wrote:
> The time logged is currently given as localtime without any time-zone
> information. This is confusing in various scenarios.
> 
> Examples:
> * If one is travelling across time-zones and the timestamps in the log
> appear out of order.

Stop updating multiple times per hour!  :D

> * Comparing dates with `datediff` gives an offset by the time-zone
> 
> This patch would reformat the time-stamp to a full ISO-8601 version.
> It includes the 'T' separating date and time. This could be removed.
> 
> Old: [2019-03-04 16:15]
> New: [2019-03-04T16:15-05:00]
> 

Can we switch from localtime() to gmtime() and just use UTC?


> Signed-off-by: Florian Wehner <florian at whnr.de>
> ---
>  lib/libalpm/log.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/libalpm/log.c b/lib/libalpm/log.c
> index e46ad3c3..cf869a08 100644
> --- a/lib/libalpm/log.c
> +++ b/lib/libalpm/log.c
> @@ -20,6 +20,7 @@
>  
>  #include <stdio.h>
>  #include <stdarg.h>
> +#include <stdlib.h>
>  #include <errno.h>
>  #include <syslog.h>
>  
> @@ -37,12 +38,17 @@
>  static int _alpm_log_leader(FILE *f, const char *prefix)
>  {
>  	time_t t = time(NULL);
> +	int tz_h, tz_m;
>  	struct tm *tm = localtime(&t);
>  
> +	/* Calculate the timezone offset ±hh:mm */
> +	tz_h = tm->tm_gmtoff/3600;
> +	tz_m = abs(tm->tm_gmtoff - (tz_h*3600))/60;
> +
>  	/* Use ISO-8601 date format */
> -	return fprintf(f, "[%04d-%02d-%02d %02d:%02d] [%s] ",
> +	return fprintf(f, "[%04d-%02d-%02dT%02d:%02d%+03d:%02d] [%s] ",
>  			tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
> -			tm->tm_hour, tm->tm_min, prefix);
> +			tm->tm_hour, tm->tm_min, tz_h, tz_m, prefix);
>  }
>  
>  /** A printf-like function for logging.
>