[Crash-utility] [PATCH v2] Append time zone to output of date and time

[lijiang]

在 2020年09月11日 14:01, HAGIO KAZUHITO(萩尾　一仁) 写道:
> Hi Lianbo,
> 
> Thank you for reviewing this.
> 
> -----Original Message-----
> ...
>>>  /*
>>> + * Convert a calendar time into a null-terminated string like ctime(), but
>>> + * the result string contains the time zone string and does not ends with a
>>> + * linefeed ('\n').  If localtime() or strftime() fails, fail back to return
>>> + * POSIX time (seconds since the Epoch) or ctime() string respectively.
>>> + *
>>> + * NOTE: The return value points to a statically allocated string which is
>>> + * overwritten by subsequent calls.
>>> + */
>>
>> Although it simplifies the context in which it is called, the definition of the
>> static variable could not be very good, and that could leave some potential risks
>> as you mentioned in the code comment.
>>
>> In addition, I noticed that there are not many calls to the ctime_tz(). Could it
>> be better like this?
>>
>> int ctime_tz(time_t *timep, char *buf, int size)
>>
>> ...
>> ret = ctime_tz(&time_now, buffer, sizeof(buffer));
>> ...
> 
> Yeah it might be safer, but I would not like to have an additional buffer only
> for this functionality and there is no cases that the allocated buffer is reused
> in the current crash source.  That behavior and interface are same as the original
> ctime() (please see the manpage of ctime), so we can just replace it with the
> ctime_tz() and it will be convenient for developers who are used to ctime().
> 
> I took the convenience rather than the safety here.  Is it unacceptable?
> 
No problem, this is also acceptable because it is not a serious problem.

Thanks.
Acked-by: Lianbo Jiang <lijiang at redhat.com>

> Thanks,
> Kazu
> 
>>
>> Thanks.
>> Lianbo
>>
>>> +char *
>>> +ctime_tz(time_t *timep)
>>> +{
>>> +	static char buf[64];
>>> +	struct tm *tm;
>>> +	size_t size;
>>> +
>>> +	if (!timep)
>>> +		return NULL;
>>> +
>>> +	tm = localtime(timep);
>>> +	if (!tm) {
>>> +		snprintf(buf, sizeof(buf), "%ld", *timep);
>>> +		return buf;
>>> +	}
>>> +
>>> +	size = strftime(buf, sizeof(buf), "%a %b %e %T %Z %Y", tm);
>>> +	if (!size)
>>> +		return strip_linefeeds(ctime(timep));
>>> +
>>> +	return buf;
>>> +}
>>> +
>>> +/*
>>>   *  Stall for a number of microseconds.
>>>   */
>>>  void
>>>
>