On 6/10/2017 10:30 PM, Eric Blake wrote: > On 06/10/2017 08:48 AM, cyg Simple wrote: > >> >> Uhm, 'wt' and 'wb' came from MS itself. > > Not quite. fopen(,"wb") comes from POSIX. "wb" is probably a microsoft > extension, but it is certainly not in POSIX nor in glibc. >
I think it's a C standard so it should be in glibc. It may be mentioned in the POSIX standard as in support of the C standard. >> GNU GCC was adapted to allow it > > Huh? It's not whether the compiler allows it, but whether libc allows > it. ALL libc that are remotely close to POSIX compliant support > fopen(,"wb"), but only Windows platforms (and NOT glibc) support > fopen(,"wt"). > Looking at http://www.cplusplus.com/reference/cstdio/fopen/ I see: "If additional characters follow the sequence, the behavior depends on the library implementation: some implementations may ignore additional characters so that for example an additional "t" (sometimes used to explicitly state a text file) is accepted." There is also a lot of discussion about the topic at: https://stackoverflow.com/questions/229924/difference-between-files-writen-in-binary-and-text-mode As for glibc, it will just ignore the extra character but it allows the use of "wt"; it just means nothing to that C runtime library. It does aide in portable code though. As for me conflating GCC with a C runtime - please forgive my lapse in memory. -- cyg Simple -- 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
