On May 12 11:01, Peter Rosin wrote: > Den 2011-05-11 19:34 skrev Corinna Vinschen: > > On May 11 16:52, Peter Rosin wrote: > >> Hello! > >> > >> The following STC hints at a problem in strptime: > ... > >> Opengroup has this to say about only filling in some fields: > >> > >> "It is unspecified whether multiple calls to strptime() > >> using the same tm structure will update the current > >> contents of the structure or overwrite all contents of > >> the structure. Conforming applications should make a > >> single call to strptime() with a format and all data > >> needed to completely specify the date and time being > >> converted." > >> > >> but I don't think it applies since indeed I do completely specify > >> the date in my strptime call. > > > > The Cygwin implementation of strptime is taken from NetBSD and enhanced > > only in terms of support for the E and O modifiers. The NetBSD and > > OpenBSD versions also support a non-POSIX format specifier %u (day of > > week, monday = 1). Other than that, the Cygwin strptime behaves exactly > > as the BSD implementation. tm_wday is only set if you specify %a, %A or > > %w. tm_yday is only set if you specify %j. > > > > Despite the example in the strptime man page of POSIX.1-2008, POSIX does > > not specify that strptime has to fill out tm fields which are not also > > specified in the format string. You should better memset the tm > > structure to 0 before calling strptime. > > Since you pulled out your "POSIX does not require it" card, I'm grasping > for my "Cygwin should behave like Linux" card. :-)
I'm not so much pulling the POSIX card, but rather the BSD/upstream card. Consider this: The Cygwin version behaves pretty exactly like the BSD version since it *is* the BSD version. Should you ever have to port your application to Open/Free/NetBSD, you will see the exact same problem. Whatever we do with the Cygwin strptime eventually, you still have to consider that your application is *not* portable. > Seriously, of course I need to handle quirks in strptime if I want the > users of my application to be happy, but that does not mean that strptime > can't be a little bit more helpful on Cygwin. Maybe someone with a > copyright assignment can find some inspiration in the patch [1] I sent > for the newlib strptime? I'll take a look. Corinna -- Corinna Vinschen Please, send mails regarding Cygwin to Cygwin Project Co-Leader cygwin AT cygwin DOT com Red Hat -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
