> On 16 Sep 2019, at 16:06, Doug Graham <edougra@xxxxxxxxx> wrote: > >> Case in point; EAGAIN can come if you give your fd to another process >> and continue using it yourself. > >> Short counts; It is documented behavior that read() and write() may >> return short counts. It is not documented why, so you can not make >> any assumptions. > > You might be right about short counts but if you're right about > EAGAIN, there are > bugs everywhere. My first attempt at working around my "make: write error" > failure was to pipe make into cat or tee, eg: "make | tee make.log". But that > caused both cat and tee to fail with EAGAIN. So they have the same "bug" as > make. Also note that make is just calling printf normally and then > just before exiting, > it calls ferror(stdout) to see if any error occurred when it > previously wrote to stdout. > ferror() is returning true. So now the bug has moved into the C library. Dumb question: shouldn't whatever is calling fork() (here 'make' I believe) be dup()'ing the FDs just in case the called program does something odd with them like set O_NONBLOCK? That's what I've always done before fork(), and I believe what the venerable Mr Stevens recommends. -- Alex Bligh _______________________________________________ openssh-unix-dev mailing list openssh-unix-dev@xxxxxxxxxxx https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev
