Implementing Linux Select Io multiplexing c/s server code

Verified available under Ubuntu

Server-side

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <arpa/inet.h>
#include <sys/select.h>

#define MAXBUF 256
#define Maxlisten 8
#define PORT 8888

struct MSGTEMP
{
int num;
Char *s;
};

int main ()
{
int clen,dirnum,opt=1,i,nbyte;
int listenfd,clientfd,maxfd;
int client[fd_setsize];

struct sockaddr_in client_addr,server_addr;
Char Readbuf[maxbuf],writebuf[maxbuf];
struct Msgtemp msg[fd_setsize];
Fd_set RSet, Allset;

if ((Listenfd=socket (af_inet,sock_stream,0)) <0) {
Perror ("Socket Error:");
Exit (1);
}
Clen = sizeof (CLIENT_ADDR);
Bzero (&server_addr,0);
Server_addr.sin_family =af_inet;
Server_addr.sin_addr.s_addr=htonl (Inaddr_any);
Server_addr.sin_port=htons (port);

SetSockOpt (Listenfd,sol_socket,so_reuseaddr, (char*) &opt,sizeof (opt));
if (Bind (LISTENFD, (struct sockaddr *) &server_addr,sizeof (SERVER_ADDR)) <0) {
Perror ("bind error");
Exit (1);
}
if (Listen (Listenfd,maxlisten) <0) {
Perror ("Listen error:");
Exit (1);
}

MAXFD = LISTENFD;
for (i = 0; i < fd_setsize; i++)
Client[i] =-1;

Fd_zero (&allset);
Fd_set (LISTENFD, &allset);


while (1) {
RSet = Allset;
if (select (maxfd+1, &rset, NULL, NULL, NULL) <0)
{
Perror ("select");
return-1;
}
if (Fd_isset (LISTENFD, &rset)) {/* Is there a new connection coming in */
Clientfd=accept (LISTENFD, (struct sockaddr *) &client_addr,&clen);
if (Clientfd < 0)
{
Perror ("accept");
}
printf ("New Connection FD =%d\n", CLIENTFD);
Fd_set (CLIENTFD, &allset);
MAXFD = clientfd > maxfd? CLIENTFD:MAXFD;
for (i = 0; i < fd_setsize; i++)
if (Client[i] < 0) {
Client[i] = CLIENTFD;
Break
}
}
for (i = 0; i < fd_setsize; i++)
{
if (Fd_isset (Client[i], &rset)) {
if ((Nbyte = Read (Client[i], readbuf, maxbuf)) < 0) {
Perror ("read");
Continue

}
else if (Nbyte ==0)
{
Close (Client[i]);
FD_CLR (Client[i], &allset);
printf ("Connection fd =%d closed\n", client[i]);
Client[i] =-1;
Msg[i].num = 0;
MSG[I].S = NULL;

}
else{
printf ("recv msg from FD =%d:%s\n", client[i],readbuf);

MSG[I].S = Readbuf;
sprintf (Writebuf, "%03d:%s", MSG[I].NUM,MSG[I].S);
Write (Client[i], Writebuf, strlen (WRITEBUF) +1);
Msg[i].num + +;
}

}
}






}
return 0;
}

Client

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <arpa/inet.h>
#include <fcntl.h>

#define MAXBUF 256
#define PORT 8888

int main ()
{
int ssock;
int clen,readbytes,fd2,i;
struct sockaddr_in server_addr;
Char Writebuf[maxbuf],readbuf[maxbuf],file_path[maxbuf];

if ((Ssock=socket (af_inet,sock_stream,0)) <0) {
Perror ("Socket Error:");
Exit (1);
}
Clen = sizeof (SERVER_ADDR);
Bzero (&server_addr,0);
Server_addr.sin_family =af_inet;
SERVER_ADDR.SIN_ADDR.S_ADDR=INET_ADDR ("127.0.0.1");
Server_addr.sin_port =htons (port);
if (Connect (ssock, (struct sockaddr *) &server_addr,clen) <0) {
Perror ("Connect error:");
Exit (1);
}

while (1)
{
printf ("Input msg:");
Fgets (Writebuf,maxbuf,stdin);
if (write (SSOCK,WRITEBUF,MAXBUF) <0)
{
Perror ("Write Error:");
}

Readbytes=read (SSOCK,READBUF,MAXBUF);
if (readbytes <0)
{

Perror ("Read error:");
Exit (1);
}
if (readbytes ==0)
{
printf ("Connection closed \ n");
Break
}


printf ("%s\n", readbuf);
}

Close (Ssock);

return 0;
}

Implementing Linux Select Io multiplexing c/s server code