- \footnotesize
- \begin{lstlisting}{}
-/* Subroutines declaration */
-void ServEcho(int sockfd);
-/* Program beginning */
-int main(int argc, char *argv[])
-{
- int list_fd, conn_fd;
- pid_t pid;
- struct sockaddr_in serv_add;
- ....
- /* create socket */
- if ( (list_fd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
- perror("Socket creation error");
- exit(-1);
- }
- /* initialize address */
- memset((void *)&serv_add, 0, sizeof(serv_add)); /* clear server address */
- serv_add.sin_family = AF_INET; /* address type is INET */
- serv_add.sin_port = htons(13); /* daytime port is 13 */
- serv_add.sin_addr.s_addr = htonl(INADDR_ANY); /* connect from anywhere */
- /* bind socket */
- if (bind(list_fd, (struct sockaddr *)&serv_add, sizeof(serv_add)) < 0) {
- perror("bind error");
- exit(-1);
- }
- /* listen on socket */
- if (listen(list_fd, BACKLOG) < 0 ) {
- perror("listen error");
- exit(-1);
- }
- /* handle echo to client */
- while (1) {
- /* accept connection */
- if ( (conn_fd = accept(list_fd, NULL, NULL)) < 0) {
- perror("accept error");
- exit(-1);
- }
- /* fork to handle connection */
- if ( (pid = fork()) < 0 ){
- perror("fork error");
- exit(-1);
- }
- if (pid == 0) { /* child */
- close(list_fd); /* close listening socket */
- SockEcho(conn_fd); /* handle echo */
- exit(0);
- } else { /* parent */
- close(conn_fd); /* close connected socket */
- }
- }
- /* normal exit, never reached */
- exit(0);
-}
- \end{lstlisting}