linux c select函数使用求解释

      代码非常easy，就是发送c语言发送http请求。但 i= read(sockfd, buf, BUFSIZE-1); 能够正常执行， 

替换为i= Read(sockfd, buf, BUFSIZE-1);后程序退出，不知什么原因，求解答。

#include <stdio.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <time.h>
#include <errno.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/wait.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <arpa/inet.h>
 
#define IPSTR "180.97.33.107"
#define PORT 80
#define BUFSIZE 1024 * 1024 * 2

int Read(int fd, char *buf, int count) {
    int nread, totlen = 0;

    while (totlen != count) {
        nread = read(fd, buf, count - totlen);
        if (nread == 0)
            return totlen;
        if (nread == -1) 
            return -1; 
        totlen += nread;
        buf += nread;
    }   
    return totlen;
}

 
int main(int argc, char **argv)
{
        int sockfd, ret, i, h;
        struct sockaddr_in servaddr;
        char str1[4096], buf[BUFSIZE];
        socklen_t len;
        fd_set   t_set1;
        struct timeval  tv;
 
        if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0 ) {
                printf("---socket error!
");
                exit(0);
        };
 
        bzero(&servaddr, sizeof(servaddr));
        servaddr.sin_family = AF_INET;
        servaddr.sin_port = htons(PORT);
        if (inet_pton(AF_INET, IPSTR, &servaddr.sin_addr) <= 0 ){
                printf("--inet_pton error!
");
                exit(0);
        };
 
        if (connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr)) < 0){
                printf("connect error!
");
                exit(0);
        }

        memset(str1, 0, 4096);
        strcat(str1, "GET / HTTP/1.1
");
        strcat(str1, "Host: www.baidu.com
");
        strcat(str1, "

");
        printf("%s",str1);
 
        ret = write(sockfd,str1,strlen(str1));
        if (ret < 0) {
		printf("errno = %d strerror = %s
",errno, strerror(errno));
                exit(0);
        }else{
		printf("send %d size
", ret);
        }
 
        FD_ZERO(&t_set1);
        FD_SET(sockfd, &t_set1);
 
        while(1){
                tv.tv_sec= 2;
                tv.tv_usec= 0;
                h= 0;
                printf("--------------->1
");
                h= select(sockfd +1, &t_set1, NULL, NULL, &tv);
                printf("--------------->2
");
 
		printf("h =================== %d
", h);
                //if (h == 0) continue;
                if (h < 0) {
                        close(sockfd);
			printf("select error 
");
                        return -1;
                }
 
                if (h > 0){
                        memset(buf, 0, BUFSIZE);
                        i= read(sockfd, buf, BUFSIZE-1);
                        //i= Read(sockfd, buf, BUFSIZE-1);
			printf("i ========================== %d", i);
                        if (i==0){
                                close(sockfd);
				printf("stop .................
");
                                return -1;
                        }
                        printf("%s
", buf);
                }
        }
        close(sockfd);
        return 0;
}