On Tue, 11 Feb 2020 22:31:12 +0100 Peter Dons Tychsen wrote: > On Tue, 2020-02-11 at 22:16 +0900, Takashi Yano wrote: > > however, I found the real cause is that errno is accidentally set > > by kill() in pty system calls. That is, the problem is not in the > > kill() itself but in usage of it. Cygwin older than 3.1.0 does not > > have these code in pty. > > OK, is there a fix for that or is that the fix you already pushed? And > what is wrong with the usage of kill(). How can kill() be used > incorrectly?
POSIX system calls set global variable errno to appropriate value when the system calls fail. http://man7.org/linux/man-pages/man3/errno.3.html My failure in pty code was that I used kill() in pty system calls. kill() can be used check if the process is still alive by passing signal number of 0 to the second argument. It returns -1 if the process already exited. However, in this case errno is set to ESRCH. As a result, the errno value which pty system call set is accidentally overwritten by kill(). The patch was already accepted and pushed to git repository. I hope cygwin 3.1.3 which applied this patch will be released shortly. -- Takashi Yano <takashi.y...@nifty.ne.jp> -- 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
