linux c select函数使用求解释

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代码很简单，就是发送c语言发送http请求，但 i= read(sockfd, buf, BUFSIZE-1); 可以正常运行，

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 * 2int 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!\n");                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!\n");                exit(0);        };         if (connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr)) < 0){                printf("connect error!\n");                exit(0);        }        memset(str1, 0, 4096);        strcat(str1, "GET / HTTP/1.1\n");        strcat(str1, "Host: www.baidu.com\n");        strcat(str1, "\n\n");        printf("%s",str1);         ret = write(sockfd,str1,strlen(str1));        if (ret < 0) {printf("errno = %d strerror = %s\n",errno, strerror(errno));                exit(0);        }else{printf("send %d size\n", ret);        }         FD_ZERO(&t_set1);        FD_SET(sockfd, &t_set1);         while(1){                tv.tv_sec= 2;                tv.tv_usec= 0;                h= 0;                printf("--------------->1\n");                h= select(sockfd +1, &t_set1, NULL, NULL, &tv);                printf("--------------->2\n"); printf("h =================== %d\n", h);                //if (h == 0) continue;                if (h < 0) {                        close(sockfd);printf("select error \n");                        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 .................\n");                                return -1;                        }                        printf("%s\n", buf);                }        }        close(sockfd);        return 0;}

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