date() should not append a final "\n" ?!?

Kurt Hornik Kurt.Hornik@ci.tuwien.ac.at
Thu, 19 Aug 1999 12:11:09 +0200 (CEST)


>>>>> Martin Maechler writes:

>>>>> On Thu, 19 Aug 1999 11:43:46 +0200 (CEST), Kurt Hornik <Kurt.Hornik@ci.tuwien.ac.at> said:
>>>>> Martin Maechler writes:
>>>>> On Thu, 19 Aug 1999 10:45:35 +0200,
>>>>> Martin Maechler (MM) wrote:

MM> Between R 0.63.2 and 0.64, the behavior of 
MM> date()
MM> has been changed in order to become platform independent.
MM> It now uses POSIX calls, basically

MM> time_t t;
MM> time(&t);
MM> return ctime(&t);


MM> This currently returns (for me on Sun SPARC Solaris)

>>>>>> date()
MM> [1] "Thu Aug 19 10:36:28 1999\n"

MM> where I think the final "\n" is really UNdesired.

FrL> Yes!

>>> Okay,
>>> I checked  Lewine (1991) "POSIX Programmer's Guide" :

>>> POSIX specifies that ctime() has a final "\n" 
>>> (before the string terminator \0)
>>> and always length 26 (incl. terminator)

>>> Hence, we have to drop the final "\n",
>>> already in function R_Date() which is [in src/main/platform.c]
>>> currently
>>> char *R_Date()
>>> {
>>> time_t t;
>>> time(&t);
>>> return ctime(&t);
>>> }

>>> How can we drop is this done in the most elegant way?
>>> (without having to allocate a  char[26] ?)

KH> Be brutal, do

KH> date <- function() substring(.Internal(date()), 1, 24)

> Kurt, I said
> 		"most elegant way"
> about 5 lines above..

But you did not define `elegant' ... :-)

> And also for the C API, we want  R_Date() to be correct.

Define `correct'.  That would be without the trailing newline?

> {{I really wonder that the POSIX people where thinking when they
>   appended the "\n";  
>   appending afterwards is always much easier than removing....
> }}


Suggestion:

	return strtok(ctime(&t), "\n");

-k
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-devel-request@stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._