Server side: I open the server and connect the client. The automatic response from server is an error; Error reading from socket. Then prints out a blank message from client and skips to message for the server to send back.
Client side: Client automatically prompts, please enter message, as soon as it connects. When you enter a message, it prints blank space like a new line char in the buffer and the repeats the please enter a message prompt. What am I doing wrong? BTW I cleaned it up a great deal Salem and improved the indentation.
SERVER:
Code:
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
#include <sys/select.h>
int main(int argc, char *argv[]) {
int sockfd, newsockfd, portno, i, b, fdmax;
struct sockaddr_in serv_addr, cli_addr;
socklen_t clilen;
char buffer[1024];
fd_set master;
fd_set read_fds;
int yes = 1;
if(argc < 2) fprintf(stderr, "No port provided.\n");
FD_ZERO(&master);
FD_ZERO(&read_fds);
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if(sockfd < 0) fprintf(stderr, "Error creating socket.\n");
if(setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int)) < 0) fprintf(stderr, "Socket already in use.\n");
bzero((char *) &serv_addr, sizeof(serv_addr));
portno = atoi(argv[1]);
serv_addr.sin_family = AF_INET;
serv_addr.sin_addr.s_addr = INADDR_ANY;
serv_addr.sin_port = htons(portno);
if(bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0) fprintf(stderr, "Error binding to socket.\n");
listen(sockfd, 10);
clilen = sizeof(cli_addr);
FD_SET(sockfd, &master);
fdmax = sockfd;
for( ; ; ) {
read_fds = master;
if(select(fdmax+1, &read_fds, NULL, NULL, NULL) < 0) fprintf(stderr, "Select error.\n");
for(i = 0; i <= fdmax; i++) {
if(FD_ISSET(i, &read_fds)) {
if(i == sockfd) {
newsockfd = accept(sockfd, (struct sockaddr *) &cli_addr, &clilen);
if(newsockfd < 0) fprintf(stderr, "Error accepting new connection.\n");
FD_SET(newsockfd, &master);
if(newsockfd > fdmax) fdmax = newsockfd;
}
fprintf(stdout, "New connection from %c on %d.\n", inet_ntoa(cli_addr.sin_addr), newsockfd);
}
/*handle data, close connection, remove from temp set(read_fds)*/
for( ; ; ) {
int b = sizeof(buffer); if(b > 0) bzero(buffer, 1024);
if(recv(i, buffer, strlen(buffer)-1, 0) < 0) fprintf(stderr, "Error reading from socket.\n");
fprintf(stdout, "Client: %s\n", buffer);
b = sizeof(buffer); if(b > 0) bzero(buffer, 1024);
fprintf(stdout, "message: ");
fgets(buffer, sizeof(buffer), stdin);
if(send(i, buffer, strlen(buffer)-1, 0) < 0) fprintf(stderr, "Error writing to socket.\n");
}
close(i);
FD_CLR(i, &read_fds);
}
}
}
CLIENT:
Code:
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
int main(int argc, char *argv[]) {
int sockfd, portno;
char buffer[1024];
struct hostent *server;
struct sockaddr_in serv_addr;
if(argc < 3) fprintf(stderr, "Ussage: %s IP Address port #\n", argv[0]);
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if(sockfd < 0) fprintf(stderr, "Error creating socket.\n");
bzero((char *) &serv_addr, sizeof(serv_addr));
server = gethostbyname(argv[1]);
if(server == NULL) fprintf(stderr, "No such host.\n");
portno = atoi(argv[2]);
serv_addr.sin_family = AF_INET;
memcpy(&serv_addr.sin_addr.s_addr, server->h_addr, server->h_length);
serv_addr.sin_port = htons(portno);
if(connect(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0) fprintf(stderr, "Error connecting to server.\n");
for( ; ; ) {
fprintf(stdout, "Please enter the message: ");
int i = sizeof(buffer); if(i > 0) bzero(buffer, 1024);
fgets(buffer,sizeof(buffer), stdin);
if(send(sockfd, buffer, strlen(buffer)-1, 0)< 0)
fprintf(stderr, "ERROR writing to socket.\n");
i = sizeof(buffer); if(i > 0) bzero(buffer, 1024);
if(recv(sockfd, buffer, strlen(buffer)-1, 0)< 0)
fprintf(stderr, "ERROR reading from socket.\n");
printf("%s\n", buffer);
}
close(sockfd);
}
Any help is appreciated!