#include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <arpa/inet.h> #include <sys/socket.h> void error_handling(char *message); int main(int argc, char *argv[]) { int serv_sock; int clnt_sock; struct sockaddr_in serv_addr; struct sockaddr_in clnt_addr; socklen_t clnt_addr_size; char message[] = "Hello Master HaKu!"; if (argc != 2) { printf("Usage: %s <port>\n", argv[0]); exit(1); } serv_sock = socket(AF_INET, SOCK_STREAM, 0); if (serv_sock == -1) error_handling("sock() error"); memset(&serv_addr, 0, sizeof(serv_addr)); serv_addr.sin_family = AF_INET; serv_addr.sin_addr.s_addr = htonl(INADDR_ANY); serv_addr.sin_port = htons(atoi(argv[1])); if (bind(serv_sock, (struct sockaddr*)&serv_addr, sizeof(serv_addr)) == -1) error_handling("bind() error"); if (listen(serv_sock, 5) == -1) error_handling("listen() error"); clnt_addr_size = sizeof(clnt_addr); clnt_sock = accept(serv_sock, (struct sockaddr*)&clnt_addr, &clnt_addr_size); if (clnt_sock == -1) error_handling("accept() error"); write(clnt_sock, message, sizeof(message)); close(clnt_sock); close(serv_sock); return 0; } void error_handling(char *message) { fputs(message, stderr); fputc(\'\n\', stderr); exit(1); }