Jan Vroonhof wrote: No. They are always as follows: #define SIG_DFL ((__sighandler_t)0) /* default signal handling */ #define SIG_IGN ((__sighandler_t)1) /* ignore signal */ #define SIG_ERR ((__sighandler_t)-1) /* error return from signal */ The problem of libgpm assuming that signal() has SysV semantics would be solved by using sigaction(). However, if the problem also exists in libc-5 versions of libgpm (and isn't caused by __USE_BSD_SIGNAL or __FAVOR_BSD getting defined), then sigaction() won't help. Also, libgpm probably needs to use the entire `struct sigaction' which is returned in the third argument to sigaction(), not just the sa_handler field. If libgpm reinstalls the old sa_handler with the wrong sa_flags and/or sa_mask, the results could be unpredictable. -- Glynn Clements <glynn(a)sensei.co.uk&gt;