C-socklib.c

/*SOCKLIB.C * This file contains functions used lots when writing Internet client/server programs. The both main function here is: *-------int Make_server_socket (portnum) return a server socket OR-1 if error *-------I NT Make_server_socket_q (portnum,backlog) *-------int connect_to_server (char * hostname,int portnum) return a connected s Ocket or-1 If error*/#include<stdio.h>#include<unistd.h>#include<sys/types.h>#include<sys/socket.h>#include<netinet/inch.h>#include<netdb.h>#include<time.h>#include<strings.h>#defineHostlen 256#defineBACKLOG 1intMake_server_socket_q (int,int); intMake_server_socket (intportnum) {     returnmake_server_socket_q (portnum,backlog);} intMake_server_socket_q (intPortnum,intbacklog) {     structSockaddr_in saddr;/*build our address here*/     structHostent * HP;/* This was part of our*/     CharHostname[hostlen];/*Address*/     intsock_id;/*The socket*/sock_id= Socket (Pf_inet,sock_stream,0);/*get a socket*/     if(sock_id = =-1)         return-1; /*Build address Andbind it to socket*/bzero ((void*) &saddr,sizeof(SADDR));/*clear out struct*/gethostname (Hostname,hostlen); /*where am I?*/HP= gethostbyname (hostname);/*get Infoabout host fill in host part*/bcopy ((void*) HP-H_ADDR, (void*) &saddr.sin_addr,hp->h_length); Saddr.sin_port= Htons (Portnum);/*fill in Socket port*/saddr.sin_family= Af_inet;/*fill in addr family*/     if(Bind (sock_id, (structSOCKADDR *) &saddr,sizeof(SADDR)) !=0)         return-1; /*arrange for incoming calls*/     if(Listen (sock_id,backlog)! =0)         return-1; returnsock_id;} intConnect_to_server (Char* Host,intportnum) {     intsock; structSockaddr_in Servadd;/* the number to call*/     structHostent *hp;/*used to get number*/     /*step 1:get a socket*/sock= Socket (Af_inet,sock_stream,0); if(Sock = =-1)         return-1; /*Step 2:connect to server*/bzero (&servadd,sizeof(Servadd));/*Zero The address*/HP= gethostbyname (host);/*Lookup Host ' s IP #*/     if(HP = =NULL)return-1; Bcopy (HP->h_addr, (structSOCKADDR *) &servadd.sin_addr,hp->h_length); Servadd.sin_port= Htons (Portnum);/*fill in Port number*/servadd.sin_family= Af_inet;/*fill in socket type*/     if(Connect (sock,structSOCKADDR *) &servadd,sizeof(Servadd)) !=0)         return-1; returnsock;}

C-socklib.c