Socket远程执行命令并结果回传（客户端）

/*
*客户端,执行命令，回传执行结果
*By rekken
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <netinet/in.h>
#include <unistd.h>
#include <string.h>
#define SERVERPORT 3490
#define BACKLOG 10
#define MAX_CONNECTED_NO 10
#define MAXDATASIZE 120
int main()
{
        //declare the variable to be used
    FILE *pp;;    //used for file handle, pp used as buf after doing command

    char sendout[65535];    //used for store the data retrived from the file
    struct sockaddr_in server_sockaddr,client_sockaddr;    //for create socket
    int sin_size,recvbytes,sendbytes;    //recv and send used for recv() and send()
    int sockfd,client_fd;    //for socket creation
    char buf[MAXDATASIZE];    //store the file dir from recv()
    char output[MAXDATASIZE];
        //creat socket connection
    if((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1){
        perror("socket");
        exit(1);
    }
    printf("socket success!,sockfd=%d\n",sockfd);

        //set relevant parameters in the socketr_in struct
    server_sockaddr.sin_family=AF_INET;
    server_sockaddr.sin_port=htons(SERVERPORT);
    server_sockaddr.sin_addr.s_addr=INADDR_ANY;
    bzero(&(server_sockaddr.sin_zero),8);

        //bind the sockfd and port
    if(bind(sockfd,(struct sockaddr *)&server_sockaddr,sizeof(struct sockaddr))==-1){
        perror("bind");
        exit(1);
    }
    printf("bind success!\n");

        //begin to listen
    if(listen(sockfd,BACKLOG)==-1){
        perror("listen");
        exit(1);
    }
    printf("listening....\n");

            //call the accept(),wait for the peer's connecting
        if((client_fd=accept(sockfd,(struct sockaddr *)&client_sockaddr,&sin_size))==-1){
            perror("accept");
            exit(1);
        }

            //receive the data from the peer
        if((recvbytes=recv(client_fd,buf,sizeof(buf),0))==-1){
            perror("recv");
            exit(1);
        }
            //do the received command

        if((pp = popen(buf, "r")) == NULL )
        {
            printf("popen error!\n");
            return 0;
        }
        while(fgets(output, 255, pp))
        {
            printf("%s", output);
            if((sendbytes=send(client_fd,output,strlen(output),0))==-1){
                perror("send file");
                exit(1);
            }
            printf("send data length:%d\n",sendbytes);
        }
        pclose(pp);

        close(sockfd);
        return 1;
}

/*
*讲命令执行部分封装
*/

int do_command(int sockfd,char *command,char *output)//sockfd套接字用于结果回传，command为待执行命令，output存放执行结果
{
    FILE *pp;
    int count_byte=0;
    if((pp = popen(command, "r")) == NULL )
    {
        printf("popen error!\n");
        return 0;
    }
    while(!feof(pp)){//判断文件尾，下两行用于将文件内容保存在output中
        output[count_byte]=fgetc(pp);
        count_byte++;
    }
    if((send(sockfd,output,count_byte,0))==-1){//将执行结果发送回请求端
        perror("send file");
        exit(1);
    }
    pclose(pp);
    return count_byte;//返回值为传送字节数
}