msgio
error = msgio(fdes, ctl, data, &rv, FWRITE, &pri, &realflags);
error = msgio(fdes, ctl, data, &rv, FREAD, &pri, &flags);
error = msgio(fdes, ctl, data, &rv, FWRITE, &pri, &flags);
static int msgio(int fdes, struct strbuf *ctl, struct strbuf *data, int *rval,
if ((error = msgio(fdes, ctl, data, &rv, FREAD, &pri,