- #include <stdio.h>
- #include <string.h>
- #include <errno.h>
- #include <sys/socket.h>
- #include <resolv.h>
- #include <stdlib.h>
- #include <netinet/in.h>
- #include <arpa/inet.h>
- #include <unistd.h>
- #define MAXBUF 1024
- int main(int argc, char **argv)
- {
- int sockfd;
- struct sockaddr_in dest;
- char buffer[MAXBUF];
- if (argc != 3) {
- printf
- ("参数格式错误!正确用法如下:/n/t/t%s IP地址 端口/n/t比如:/t%s 127.0.0.1 80/n此程序用来从某个 IP 地址的服务器某个端口接收最多 MAXBUF 个字节的消息",
- argv[0], argv[0]);
- exit(0);
- }
- if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
- perror("Socket");
- exit(errno);
- }
- bzero(&dest, sizeof(dest));
- dest.sin_family = AF_INET;
- dest.sin_port = htons(atoi(argv[2]));
- if (inet_aton(argv[1], (struct in_addr *) &dest.sin_addr.s_addr) == 0) {
- perror(argv[1]);
- exit(errno);
- }
- if (connect(sockfd, (struct sockaddr *) &dest, sizeof(dest)) != 0) {
- perror("Connect ");
- exit(errno);
- }
- bzero(buffer, MAXBUF);
- recv(sockfd, buffer, sizeof(buffer), 0);
- printf("%s", buffer);
- close(sockfd);
- return 0;
- }
编译此程序使用如下命令:
gcc -Wall simple-socket.c |
运行此程序使用如下命令(假设你的主机上开启了ssh服务):
./a.out 127.0.0.1 22 |