UDP简单实现并发服务器和客户端简单通信-蒲公英云

UDP简单实现并发服务器和客户端简单通信

墨蓝 2022-07-14 09:40 316阅读 0赞

以下程序均未做错误处理，以后有时间一定补上

客户端

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <netinet/in.h>
#include <sys/socket.h>
int main(int argc,char **argv)
{
    int sockfd;
    int n;
    struct sockaddr_in servaddr;
    char readbuf[1000];
    char sendbuf[1000];
    sockfd = socket(AF_INET,SOCK_DGRAM,0);
    bzero(&servaddr,sizeof(servaddr));
    servaddr.sin_family = AF_INET;
    servaddr.sin_addr.s_addr = inet_addr(argv[1]);
    servaddr.sin_port = htons(3200);
    while(fgets(sendbuf,1000,stdin) != NULL)
    {
        sendto(sockfd,sendbuf,strlen(sendbuf),0,(struct sockaddr *)&servaddr,sizeof(servaddr));
        n = recvfrom(sockfd,readbuf,1000,0,NULL,NULL);
        readbuf[n] = '\0';
        fputs(readbuf,stdout);
    }
    close(sockfd);
    return 0;
}

服务器

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <netinet/in.h>
#include <sys/socket.h>
void strlwr(char *str)
{
    char *p;
    p = str;
    while(*p != '\0')
    {
        if((*p >= 'a') && (*p <= 'z'))
        {
            *p -= 32;
        }
        p++;
    }
}
int main()
{
    int sockfd;
    int n;
    struct sockaddr_in servaddr,cliaddr;
    char mesg[1000];
    socklen_t clilen;
    sockfd = socket(AF_INET,SOCK_DGRAM,0);
    bzero(&servaddr,sizeof(servaddr));
    servaddr.sin_family = AF_INET;
    servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
    servaddr.sin_port = htons(3200);
    bind(sockfd,(struct sockaddr*)&servaddr,sizeof(servaddr));
    clilen = sizeof(cliaddr);
    for(;;)
    {
        for(;;)
        {
            n = recvfrom(sockfd,mesg,1000,0,(struct sockaddr*)&cliaddr,&clilen);
            if(n == 0)
            {
                printf("client closed");
                exit(-1);
            }
            printf("******************\n");
            mesg[n] = '\0';
            printf("%s\n",mesg);
            printf("*******************\n");
            strlwr(mesg);
            sendto(sockfd,mesg,n,0,(struct sockaddr*)&cliaddr,sizeof(cliaddr));
        }
        //close(sockfd);
    }
    close(sockfd);
    return 0;
}