This is the mail archive of the
cygwin
mailing list for the Cygwin project.
Re: CR-LF handling behavior of SED changed recently - this breaks a lot of MinGW cross build scripts
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