Greetings, Bruno Haible! > In Gnulib, we have a unit test that compiles the program below as a > native Windows program (either with mingw or with MSVC), that exercises > the Gnulib select() function > > <https://git.savannah.gnu.org/gitweb/?p=gnulib.git;a=blob;f=lib/select.c;h=5a58d6ee47f5b10413d97cb7a1996d424eefc796;hb=HEAD>
> Then it does (in a Cygwin shell): > rm -f t-select-in.tmp > ./test-select-fd.exe r 0 t-select-in.tmp < /dev/null > cat t-select-in.tmp > Up to Cygwin 3.6.0, the contents of the file t-select-in.tmp was "1", > like on most other OSes, indicating that the program can read() from > file descriptor 0. But "< /dev/null" literally means "don't read from STDIN". As far as I recall (correct me if I'm wrong), READING from /dev/null is undefined and may result in undetermined behavior. > In Cygwin 3.6.1, the contents of the file t-select-in.tmp is "0", > indicating that read()ing from file descriptor 0 would block. > This is a regression. What I've gathered is that in most cases reading from /dev/null should immediately return EOF. -- With best regards, Andrey Repin Monday, April 14, 2025 14:31:08 Sorry for my terrible english... -- Problem reports: https://cygwin.com/problems.html FAQ: https://cygwin.com/faq/ Documentation: https://cygwin.com/docs.html Unsubscribe info: https://cygwin.com/ml/#unsubscribe-simple
