BSD Socket 简易入门手册.pdfVIP

socket() bind() listen() listen() socket()bind()listen() /* code to establish a socket; originally from bzs@ */ int establish(unsigned short portnum) { char myname[MAXHOSTNAME+1]; int s; struct sockaddr_in sa; struct hostent *hp; memset(sa, 0, sizeof(struct sockaddr_in)); /* clear our address */ gethostname(myname, MAXHOSTNAME); /* who are we? */ hp= gethostbyname(myname); /* get our address info */ if (hp == NULL) /* we dont exist !? */ return(-1); sa.sin_family= hp-h_addrtype; /* this is our host address */ sa.sin_port= htons(portnum); /* this is our port number */ if ((s= socket(AF_INET, SOCK_STREAM, 0)) 0) /* create socket */ return(-1); if (bind(s,sa,sizeof(struct sockaddr_in)) 0) { close(s); return(-1); /* bind address to socket */ } listen(s, 3); /* max # of queued connects */ return(s); } accept()accept() Accept() /* wait for a connection to occur on a socket created with establish() */ int get_connection(int s) { int t; /* socket of connection */ if ((t = accept(s,NULL,NULL)) 0) /* accept connection if there is one */ return(-1); return(t); } establish()get_connection() #include errno.h /* obligatory includes */ #include signal.h #include stdio.h #include unistd.h #include sys/types.h #include sys/socket.h #include sys/wait.h #include netinet/in.h #include netdb.h #define PORTNUM 50000 /* random port number, we need something */ void fireman(void); void do_something(int); main() { int s, t; if ((s= establish(PORTNUM)) 0) { /* plug in the phone */ perror(establish); exit(1); } signal(SIGCHLD, fireman); /* this eliminates zo