C语言两个进程相互通信—socket

client.c

 

#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <stdlib.h>
int main()
{
    int sockfd;
    int len;
    struct sockaddr_in address;
    int result;
    int i,byte;
    char char_recv,char_send;
    if((sockfd = socket(AF_INET,SOCK_STREAM,0)) == -1)
    {
        perror("socket");
        exit(EXIT_FAILURE);
    }
    address.sin_family = AF_INET;
    address.sin_addr.s_addr = inet_addr("127.0.0.1");
    address.sin_port = 8080;
    len = sizeof(address);
    if((result = connect(sockfd,(struct sockaddr *)&address,len)) == -1)
    {
        perror("connect");
        exit(EXIT_FAILURE);
    }

    printf("please enter the context you want to send to server :");
    scanf("%c",&char_send);

    if(byte = send(sockfd,&char_send,1,0) == -1)
    {
        perror("send");
        exit(EXIT_FAILURE);
    }
    if(byte = recv(sockfd,&char_recv,1,0) == -1)
    {
        perror("recv");
        exit(EXIT_FAILURE);
    }
    printf("receive from server %c\n",char_recv);

    close(sockfd);
    exit(0);
}

 server.c

 

#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <stdlib.h>
char dict(char temp)
{
    if(temp == 'Z')
    {
        return 'A';
    }
    return temp+1;
}
int main()
{
    int server_sockfd,client_sockfd;
    int server_len,client_len;
    struct sockaddr_in server_address;
    struct sockaddr_in client_address;
    int i,btye;
    char char_recv,char_send;

    server_address.sin_family = AF_INET;
    server_address.sin_addr.s_addr = inet_addr("127.0.0.1");
    server_address.sin_port = 8080;
    server_len = sizeof(server_address);

    server_sockfd = socket(AF_INET,SOCK_STREAM,0);

    bind(server_sockfd,(struct sockaddr *)&server_address,server_len);

    listen(server_sockfd,5);
    printf("server waiting for connect\n");

    client_len = sizeof(client_address);
    client_sockfd = accept(server_sockfd,(struct sockaddr *)&client_address,(socklen_t *)&client_len);

    if(btye = recv(client_sockfd,&char_recv,1,0) == -1)
    {
        perror("recv");
        exit(EXIT_FAILURE);
    }
    printf("receive from client is %c\n",char_recv);
    char_send = dict(char_recv);
    if(btye = send(client_sockfd,&char_send,1,0) == -1)
    {
        perror("send");
        exit(EXIT_FAILURE);
    }

    shutdown(client_sockfd,2);
    shutdown(server_sockfd,2);
    return 0;
}