Client Part :
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <netdb.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
int main(int argc,char *argv[])
{
int sockfd;
char buffer[1024];
struct sockaddr_in server_addr;
struct hostent *host;
int portnumber,nbytes;
if(argc!=3)
{
printf("wrong 1");
exit(1);
}
if((host=gethostbyname(argv[1]))==NULL)
{
printf("wrong 2");
exit(1);
}
if((portnumber=atoi(argv[2])) <0)
{
printf("wrong 3");
exit(1);
}
if((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1)
{
printf("wrong 4");
exit(1);
}
bzero(&server_addr,sizeof(server_addr));
server_addr.sin_family=PF_INET;
server_addr.sin_port=htons(portnumber);
server_addr.sin_addr.s_addr=inet_addr("127.0.0.1");
printf("we are trying to connect \n");
if(connect(sockfd,(struct sockaddr*)(&server_addr),sizeof(struct sockaddr))==-1)
{
fprintf(stderr,"Connect Error:%s\a\n",strerror(errno));
exit(1);
}
printf("our connection succeeded!\n");
while(1)
{
printf("client:");
scanf("%s",buffer);
getchar();
if((nbytes=send(sockfd,buffer,strlen(buffer),0))==-1)
{
printf("send failed with error \n");
exit(1);
}
if((nbytes=recv(sockfd,buffer,strlen(buffer),0))==-1);
{
printf(stderr," Read Error:%s\n",strerror(errno));
exit(1);
}
buffer[nbytes]='\0';
printf("sever:%s\n",buffer);
}
printf("I have received:%s\n",buffer);
close(sockfd);
eixt(0);
}
Server Part :
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <netdb.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#define BACKLOG 10
int main(int argc, char *argv[])
{
int sockfd,new_fd;
int ret;
struct sockaddr_in server_addr;
struct sockaddr_in client_addr;
int sin_size,portnumber;
char buffer[1024];
if(argc!=2)
{
fprintf(stderr,"Usage:%s portnumber\a\n",argv[0]);
exit(1);
}
if((portnumber=atoi(argv[1])) <0)
{
fprintf(stderr,"Usage:%s portnumber\a\n",argv[0]);
exit(1);
}
if((sockfd=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP))==-1)
{
fprintf(stderr,"Socket error:%s\n\a",strerror(errno));
exit(1);
}
bzero(&server_addr,sizeof(server_addr));
server_addr.sin_family=AF_INET;
server_addr.sin_addr.s_addr=htonl(INADDR_ANY);
server_addr.sin_port=htons(portnumber);
if(bind(sockfd,(struct sockaddr*)(&server_addr),sizeof(struct sockaddr))==-1)
{
fprintf(stderr,"Bind error:%s\n\a",strerror(errno));
exit(1);
}
if(listen(sockfd,5)==-1)
{
fprintf(stderr,"Listen error:%s\n\a",strerror(errno));
exit(1);
}
printf("we are waiting a connection on port %d\n",portnumber);
sin_size=sizeof(struct sockaddr_in);
if((new_fd=accept(sockfd,(struct sockaddr*)(&client_addr),&sin_size))==-1)
{
fprintf(stderr,"Server get connection from %s\n",inet_ntoa(client_addr.sin_addr));
if(write(new_fd,buffer,strlen(buffer))==-1)
{
fprintf(stderr,"Write Error:%s\n",strerror(errno));
exit(1);
}
}
printf("We successfull ^^^^from %s:%d\n",inet_ntoa(client_addr.sin_addr),ntohs(client_addr.sin_port));
printf("we are waiting to receive data...\n");
while(1)
{
if((ret = recv(new_fd,buffer,sizeof(buffer),0))==-1)
{
printf("receive failed!\n");
exit(0);
}
buffer[ret]='\0';
printf("cilent: %s\n",buffer);
printf("server:");
scanf("%s",buffer);getchar();
if((ret = send(new_fd,buffer,sizeof(buffer),0))==-1)
{
printf("send failed!\n");
exit(0);
}
}
close(new_fd);
close(sockfd);
}
this is a example which an engineer do not know how to debug
So I help to debug with It.
Step One :
compile the Server and Client,e.g
compile as chat_server , chat_client
Step Tow:
run the server at the back ground ,
./chat_server 1234 & <----run this at back ground
step three:
run the client
./chat_client 127.0.0.1 1234
operat according with the indication
have fun !
