linux c編程實現vsftpd是否支持匿名賬戶

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>          /* See NOTES */
#include <sys/socket.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>


int main(int argc,char *argv[])
{
    char *passwd[4]={"212","das","123.com","dasdasf"};
    int fd;
    char buff[1024];
    struct sockaddr_in seraddr;
    char anmous[256] = "USER anonymous\r\n";
    int ret;
    struct timeval val;

    fd = socket(AF_INET,SOCK_STREAM,0);
    if(fd <=0 )
    {
        printf("*******************socket error\n");
        return -1;
    }	
    
    memset(&seraddr,0,sizeof(seraddr));
    seraddr.sin_family = AF_INET;
    seraddr.sin_port = htons(21);
    seraddr.sin_addr.s_addr = inet_addr("192.168.11.17");
   
    memset(&val,0,sizeof(val)); 
    val.tv_sec = 5;

    setsockopt(fd,SOL_SOCKET,SO_RCVTIMEO,(void*)&val, sizeof(val));
    if(connect(fd,(struct sockaddr*)&seraddr,sizeof(struct sockaddr_in)) != 0)
    {
        printf("connect error\n");
        goto out;
    }
    
    memset(buff,0,1024);   
    recv(fd,buff,1024,0);
    
    //show vsftpd version
    printf("%s\n", buff);
      
    //發送匿名賬戶登錄
    sprintf(anmous,"%s","USER anonymous\r\n");
    send(fd,anmous,strlen(anmous),0);  
    memset(buff,0,1024);   
    recv(fd,buff,1024,0);
    printf("%s\n",buff); 
 
    //331表示用戶名傳輸完成 要求輸入密碼 
    if(331 == atoi(buff))
    {
        //發送任意密碼 
        sprintf(anmous,"%s","PASS hellowold\r\n");
        send(fd,anmous,strlen(anmous),0);
        memset(buff,0,1024);   
        ret = recv(fd,buff,1024,0);
        if(ret <= 0)
        {
            printf("Not support anonymous\n");
            goto out;
        }
        printf("%s\n",buff);//發返回登錄成功

        //結束此次登錄
        sprintf(anmous,"%s","QUIT\r\n");
        send(fd,anmous,strlen(anmous),0);  
        memset(buff,0,1024);   
        recv(fd,buff,1024,0);
        printf("%s\n",buff);
     }   
    
out:
    close(fd);
    return 0;
}