linux 简易socket

linux下socket简易客户端和服务器代码，做测试用

服务器代码

server.c监测任意地址通过端口SERV_PORT过来的连接

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#include <sys/socket.h>
#include <stdio.h>
#include <sys/types.h>
#include <errno.h>
#include <netinet/in.h>
#include <sys/un.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
 
#define SERV_PORT 4564
#define LISTENQ   100
#define BUFF_SIZE 1024
 
int main(int argc,char *argv[])
{
    int listenfd = socket(AF_INET,SOCK_STREAM,0);
    if(-1 == listenfd)
    {
        perror(strerror(errno));
    }   
     
    struct sockaddr_in servaddr;
    memset(&servaddr,0,sizeof(servaddr));
    servaddr.sin_family = AF_INET;
    servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
    servaddr.sin_port = htons(SERV_PORT);
    if(-1 == bind(listenfd,(struct sockaddr*)&servaddr,
                    sizeof(servaddr)))
    {
        perror(strerror(errno));
    }
 
    listen(listenfd, LISTENQ);
     
    struct sockaddr_in client;
    int n = sizeof(client);
    int connetfd;
    pid_t child_pid;
    while(1)
    {   
        connetfd = accept(listenfd,(struct sockaddr*)&client,
                        &n);
        if(connetfd == -1)
        {   
            perror(strerror(errno));
        }
        printf("有%s客户端的连接\n",inet_ntoa(client.sin_addr));
        child_pid = fork();
        if(child_pid == -1)
        {
            perror(strerror(errno));
        }   
        if(child_pid == 0)
        {
            close(listenfd);
            char buf[BUFF_SIZE] = {0};
             
            time_t n = time(NULL);
            struct tm *t;
            t = localtime(&n);  
            sprintf(buf,"%02d:%02d:%02d",t->tm_hour,t->tm_min,t->tm_sec);
            write(connetfd,buf,strlen(buf));
            printf("已经把%s发到%s\n",buf,inet_ntoa(client.sin_addr));
 
            close(connetfd);
            exit(0);
        }
        close(connetfd);
    }
     
    return 0;   
}

客户端代码

客户端连接本地环回地址，端口为SERV_PORT

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#include <sys/socket.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include <netinet/in.h>
#include <stdlib.h>
#include <arpa/inet.h>
 
#define SERV_PORT 4564
#define BUFF_SIZE 1024
 
int main(int argc,char *argv[])
{
    int sockfd = socket(AF_INET,SOCK_STREAM,0);
    if(sockfd == -1)
        perror(strerror(errno));
     
    struct sockaddr_in servaddr;
    memset(&servaddr,0,sizeof(servaddr));
    servaddr.sin_family = AF_INET;
    servaddr.sin_port = htons(SERV_PORT);
    inet_aton(argv[1],&servaddr.sin_addr);
    if(connect(sockfd,(struct sockaddr*)&servaddr,sizeof(servaddr)) == -1)
        perror(strerror(errno)),exit(0);
    printf("连接到%s\n",argv[1]);
         
    char buf[BUFF_SIZE] = {0};  
    read(sockfd,buf,sizeof(buf));
    printf("%s\n",buf);
 
    return 0;
}