fprintf(stderr,\ exit(1); }
if ((he=gethostbyname(argv[1])) == NULL) { /* get the host info */ herror(\ exit(1); }
if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) { perror(\ exit(1); }
their_addr.sin_family = AF_INET; /* host byte order */
their_addr.sin_port = htons(PORT); /* short, network byte order */ their_addr.sin_addr = *((struct in_addr *)he->h_addr); bzero(&(their_addr.sin_zero),; /* zero the rest of the struct */ if (connect(sockfd, (struct sockaddr *)&their_addr,sizeof(struct sockaddr)) == -1) { perror(\ exit(1); }
if ((numbytes=recv(sockfd, buf, MAXDATASIZE, 0)) == -1) {
perror(\ exit(1); }
buf[numbytes] = '\\0'; printf(\ close(sockfd); return 0; }
注意，如果你在运行服务器之前运行客户程序，connect() 将返回 \信息，这非常有用。
-------------------------------------------------------------------------------- 数据包 Sockets
我不想讲更多了，所以我给出代码 talker.c 和 listener.c。
listener 在机器上等待在端口 4590 来的数据包。talker 发送数据包到 一定的机器，它包含用户在命令行输入的内容。 这里就是 listener.c： #include
#include
#define MYPORT 4950 /* the port users will be sending to */ #define MAXBUFLEN 100 main() {
int sockfd;
struct sockaddr_in my_addr; /* my address information */
struct sockaddr_in their_addr; /* connector's address information */ int addr_len, numbytes; char buf[MAXBUFLEN];
if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) { perror(\ exit(1); }
my_addr.sin_family = AF_INET; /* host byte order */
my_addr.sin_port = htons(MYPORT); /* short, network byte order */ my_addr.sin_addr.s_addr = INADDR_ANY; /* auto-fill with my IP */ bzero(&(my_addr.sin_zero),; /* zero the rest of the struct */ if (bind(sockfd, (struct sockaddr *)&my_addr, sizeof(struct sockaddr)) \\
== -1) {
perror(\ exit(1); }
addr_len = sizeof(struct sockaddr);
if ((numbytes=recvfrom(sockfd, buf, MAXBUFLEN, 0, \\ (struct sockaddr *)&their_addr, &addr_len)) == -1) { perror(\ exit(1); }
printf(\ printf(\ buf[numbytes] = '\\0';
printf(\ close(sockfd); }
注意在我们的调用 socket()，我们最后使用了 SOCK_DGRAM。同时，listen() 或者 accept()。我们在使用无连接的数据报套接 字！ 下面是 talker.c： #include
没有必要去使用 #include
#define MYPORT 4950 /* the port users will be sending to */ int main(int argc, char *argv[]) {
int sockfd;
struct sockaddr_in their_addr; /* connector's address information */ struct hostent *he; int numbytes; if (argc != 3) {
fprintf(stderr,\ exit(1); }
if ((he=gethostbyname(argv[1])) == NULL) { /* get the host info */ herror(\ exit(1); }
if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) { perror(\