rem: * there are compiler warnings on e.g. SCO OpenSwerver.  It * seems they all eventually get the right idea.
add: * there are compiler warnings on e.g. SCO OpenSwerver or AIX. * It seems they all eventually get the right idea.
context: int is_a_socket(int fd){	int v, l;	l = sizeof(int);        /* Parameters to getsockopt, setsockopt etc are very         * unstandardized across platforms, so don't be surprised if         * there are compiler warnings on e.g. SCO OpenSwerver.  It         * seems they all eventually get the right idea.         *         * Debian says: ``The fifth argument of getsockopt and         * setsockopt is in reality an int [*] (and this is what BSD         * 4.* and libc4 and libc5 have).  Some POSIX confusion         * resulted in the present socklen_t.  The draft standard has         * not been adopted yet, but glibc2 already follows it and         * also has socklen_t [*]. See also accept(2).''         *         * We now return to your regularly scheduled programming.  */	return(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0);}