FD_CLOEXEC        345 execwrappers.cpp       fcntl(i, F_SETFD, flags & ~FD_CLOEXEC);
FD_CLOEXEC         84 popen.cpp          fcntl(pipe_fds[0], F_SETFD, FD_CLOEXEC);
FD_CLOEXEC         85 popen.cpp          fcntl(pipe_fds[1], F_SETFD, FD_CLOEXEC);