多进程并发服务器

data.h

#ifndef DATA_H
#define DATA_H
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <stdlib.h>
#include <unistd.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <errno.h>
#define PORT 45178
#define maxn 1100
#define BACKLOG 10
#define IP "127.0.0.1"
#endif

server.c

#include "data.h"
void send_message(int sockfd,struct sockaddr_in client)
{
    int num;
    char sendbuf[maxn],recvbuf[maxn];
    char cliname[maxn];
    printf("You get a connection from %s 
",inet_ntoa(client.sin_addr));
    num = recv(sockfd,cliname,maxn,0);
    printf("client name is %s
",cliname);
    while(num = recv(sockfd,recvbuf,maxn,0))
    {
        num--;
        recvbuf[num] = '';
        printf("Receive a message is %s from <===>%s
",recvbuf,cliname);
        send(sockfd,recvbuf,maxn,0);
    }        

}
int main()
{
    int sockfd;
        struct sockaddr_in server_in;
        if((sockfd = socket(AF_INET,SOCK_STREAM,0)) == -1)
        {
            fprintf(stderr,"socket fail,error %s",strerror(errno));
            return -1;
        }
        bzero(&server_in,sizeof(server_in));
        server_in.sin_family = AF_INET;
        server_in.sin_port = htons(PORT);
    inet_pton(AF_INET,IP,&server_in.sin_addr);
    if(bind(sockfd,(struct sockaddr*)&server_in,sizeof(server_in)) == -1)
       {
            fprintf(stderr,"bind fail,error %s",strerror(errno));
                return -1;
    }
    listen(sockfd,BACKLOG);
    struct sockaddr_in client;
    int len = sizeof(client);
    int afd;
    int pid;
    while(1)
    {
        if((afd = accept(sockfd,(struct sockaddr*)&client,&len)) == -1)
        {
            fprintf(stderr,"accept fail,error:%s
",strerror(errno));
            exit(1);
        }
        if((pid = fork()) > 0)
        {
            close(afd);
            continue;
        }
        else if(pid == 0)
        {
            close(sockfd);
            send_message(afd,client);
            exit(0);
        }
        else
        {
            printf("fork() error!
");
            exit(0);
        }
    }    
    close(sockfd);
}

client.c

#include "data.h"
void send_message(FILE *fp,int sockfd)
{
    char sendline[maxn];
    char recvbuf[maxn];
    int num;
    printf("connect to server!
");
    printf("Please input client name :
");
    if(fgets(sendline,maxn,fp) == NULL)
    {
        printf("input name error!
");
        exit(1);
    }
    send(sockfd,sendline,maxn,0);
    while(1)
    {
        printf("Please input message !
");
        if(fgets(sendline,maxn,fp) == NULL)  break;
        send(sockfd,sendline,strlen(sendline),0);
        bzero(&recvbuf,sizeof(recvbuf));
        recv(sockfd,recvbuf,maxn,0);
        int len = strlen(recvbuf);
        recvbuf[len] = '';
        printf("client receive message is %s
",recvbuf);
    }
    printf("client exit!
");
}
int main()
{
    struct sockaddr_in client_in;
       int sockfd;
        if((sockfd = socket(AF_INET,SOCK_STREAM,0)) == -1)
        {
                fprintf(stderr,"socket fail,error %s
",strerror(errno));
                return -1;
        }
        bzero(&client_in,sizeof(client_in));
    client_in.sin_family = AF_INET;
    client_in.sin_port = htons(PORT);
       inet_pton(AF_INET,IP,&client_in.sin_addr);
    connect(sockfd,(struct sockaddr*)&client_in,sizeof(client_in)) ;
    send_message(stdin,sockfd);
    close(sockfd);
    return 0;
}