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server.c
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server.c
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#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <errno.h>
#include <pthread.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <arpa/inet.h>
#include "server.h"
#include "transmit.h"
#include "client.h"
/* --------------------------- Global Variables ---------------------------- */
int master_sockfd;
client_t clients[MAX_CLIENTS];
mgame_t games[MAX_GAMES];
pthread_mutex_t new_game_lock = PTHREAD_MUTEX_INITIALIZER;
/* ----------------------------- Helper Macros ----------------------------- */
#define SAFE_TRANSMIT(id, sockfd, command, data) \
pthread_mutex_lock(&clients[id].send_lock); \
transmit(sockfd, command, data); \
pthread_mutex_unlock(&clients[id].send_lock);
#define SAFE_TRANSMIT2(id, command, data) \
pthread_mutex_lock(&clients[id].send_lock); \
transmit(clients[id].sockfd, command, data); \
pthread_mutex_unlock(&clients[id].send_lock);
#define ENFORCE_CONTEXT(desired_status) \
if (clients[id].status != desired_status) { \
free(buffer); \
SAFE_TRANSMIT(id, sockfd, CMD_QUIT, ERR_BAD_CONTEXT); \
goto cleanup; \
}
/* --------------------------- Helper Functions ---------------------------- */
/* Return whether or not the server is currently running. */
static int is_running(void) {
int sockfd = make_connection("localhost");
if (sockfd > 0)
close(sockfd);
return sockfd > 0;
}
/* Get the PID of the server, assuming it is running. */
static pid_t get_server_pid(void) {
int sockfd = make_connection("localhost");
char resp[16] = "\0";
if (sockfd < 0)
return -1;
if (transmit(sockfd, CMD_GETPID, NULL) < 0)
return -1;
read(sockfd, resp, 16);
return atol(resp);
}
/* Shutdown the server by sending a quit message to all clients and exiting. */
static void stop_server(int retval) {
int id;
for (id = 0; id < MAX_CLIENTS; id++) {
switch (clients[id].status) {
case CLIENT_FREE:
break;
case CLIENT_CONNECTING:
case CLIENT_IDLE:
case CLIENT_WAITING:
case CLIENT_IN_GAME:
pthread_mutex_lock(&clients[id].send_lock);
transmit(clients[id].sockfd, CMD_QUIT, ERR_SERVER_STOPPING);
close(clients[id].sockfd);
pthread_mutex_unlock(&clients[id].send_lock);
}
}
close(master_sockfd);
exit(retval);
}
/* Catch signals in order to safely close client connections. */
static void catch_signal(int sig) {
if (sig == SIGTERM)
stop_server(0);
}
/* Set up the server connection but do not enter the main loop. */
static void start_server(void) {
int sockfd, id;
struct sockaddr_in serv_addr;
if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
perror("Error: cannot create socket");
exit(1);
}
/* Create socket structure. */
bzero((char *) &serv_addr, sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
serv_addr.sin_addr.s_addr = INADDR_ANY;
serv_addr.sin_port = htons(PORT);
if (bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0) {
perror("Error: couldn't bind()");
exit(1);
}
if (listen(sockfd, 16) < 0) {
perror("Error: couldn't listen()");
exit(1);
}
/* Set up remaining data. */
srand(time(NULL));
for (id = 0; id < MAX_CLIENTS; id++) {
clients[id] = (client_t) {id, CLIENT_FREE};
clients[id].request = NO_REQUEST;
pthread_mutex_init(&clients[id].send_lock, NULL);
}
for (id = 0; id < MAX_GAMES; id++) {
games[id] = (mgame_t) {id, GAME_FREE};
pthread_mutex_init(&games[id].state_lock, NULL);
pthread_mutex_init(&games[id].input_buffer.lock, NULL);
}
if (signal(SIGTERM, catch_signal) == SIG_ERR) {
printf("Error: couldn't attach a signal handler.\n");
exit(1);
}
master_sockfd = sockfd;
}
/* Daemonize the current running process, for after starting the server. */
static void daemonize(void) {
/* https://en.wikipedia.org/wiki/Daemon_(computing)#Creation */
pid_t pid = fork();
if (pid < 0) {
printf("error: couldn't fork.\n");
exit(1);
}
if (pid > 0)
exit(0); /* Forked correctly: exit parent. */
umask(0);
if (setsid() < 0) {
printf("error: couldn't create a new session.\n");
exit(1);
}
if ((chdir("/")) < 0) {
printf("error: couldn't chdir(\"/\").\n");
exit(1);
}
printf("done.\n");
freopen( "/dev/null", "r", stdin);
freopen( "/dev/null", "w", stdout);
freopen( "/dev/null", "w", stderr);
}
/* Get a free client ID. Return -1 if none are available. */
static int get_free_client_id(void) {
int id;
for (id = 0; id < MAX_CLIENTS; id++) {
if (clients[id].status == CLIENT_FREE)
return id;
}
return -1;
}
/* Get a free game ID. Return -1 if none are available. */
static int get_free_game_id(void) {
int id;
for (id = 0; id < MAX_GAMES; id++) {
if (games[id].status == GAME_FREE)
return id;
}
return -1;
}
/* Return whether or not the given client is connected from localhost. */
static int is_local_client(int id) {
char cname[INET_ADDRSTRLEN];
inet_ntop(AF_INET, &clients[id].addr.sin_addr, cname, INET_ADDRSTRLEN);
return strcmp(cname, "127.0.0.1") == 0;
}
/* Cancel any pending requests for a game. */
static void cancel_requests(int game_id) {
int id;
for (id = 0; id < MAX_CLIENTS; id++) {
if (clients[id].request == game_id) {
SAFE_TRANSMIT2(id, CMD_REJECT_REQ, NULL);
clients[id].request = NO_REQUEST;
}
}
}
/* Get the game slot that corresponds to a client ID. */
static int get_slot_for_client(int game_id, int player) {
int slot;
for (slot = 0; slot < games[game_id].slots_total; slot++) {
if (games[game_id].players[slot] == player)
return slot;
}
return EMPTY_SLOT;
}
/* Handle the logic in a running game. This runs in its own thread. */
static void* handle_game(void* arg) {
int id = *((int*) arg), action, player, slot;
input_t* input;
char *buffer;
/* Set up the game and enter the logic loop. */
setup_game(&games[id].data);
setup_multiplayer(&games[id].data, games[id].slots_total, -1, -1);
while (games[id].data.running) {
pthread_mutex_lock(&games[id].state_lock);
if (games[id].status != GAME_PLAYING) { /* All players have left. */
pthread_mutex_unlock(&games[id].state_lock);
return NULL;
}
do_logic(&games[id].data);
/* Handle unprocessed player input. */
pthread_mutex_lock(&games[id].input_buffer.lock);
while (games[id].input_buffer.first != NULL) {
/* Pop the first input item off the stack. */
input = games[id].input_buffer.first;
player = input->player;
action = input->action;
games[id].input_buffer.first = input->next;
free(input);
/* Process the input in the context of its sender. */
slot = get_slot_for_client(id, player);
if (slot == EMPTY_SLOT)
continue;
handle_serializable_input(&games[id].data, slot, action);
}
pthread_mutex_unlock(&games[id].input_buffer.lock);
/* Update all players with the current game status. */
serialize_game_data(&games[id].data, &buffer);
for (slot = 0; slot < games[id].slots_total; slot++) {
player = games[id].players[slot];
if (player == EMPTY_SLOT)
continue;
SAFE_TRANSMIT2(player, CMD_GAME_UPDATE, buffer);
}
pthread_mutex_unlock(&games[id].state_lock);
free(buffer);
usleep(1000000 / FPS);
}
/* Game has ended; inform remaining players. */
pthread_mutex_lock(&games[id].state_lock);
for (slot = 0; slot < games[id].slots_total; slot++) {
player = games[id].players[slot];
if (player == EMPTY_SLOT)
continue;
SAFE_TRANSMIT2(player, CMD_GAME_OVER, NULL);
clients[player].status = CLIENT_IDLE;
}
games[id].status = GAME_FREE;
cancel_requests(id);
pthread_mutex_unlock(&games[id].state_lock);
return NULL;
}
/* Start a game pthread. */
static void start_game_thread(int id) {
pthread_attr_t attr;
pthread_attr_init(&attr);
pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
if (pthread_create(&games[id].thread, &attr, handle_game, (void*) &id) < 0) {
pthread_attr_destroy(&attr);
stop_server(1);
}
pthread_attr_destroy(&attr);
}
/* Remove a player from a game; notify remaining players or end the game. */
static void remove_player(int id, int game_id) {
int slot;
/* Update game slots data. */
pthread_mutex_lock(&games[game_id].state_lock);
slot = get_slot_for_client(game_id, id);
if (slot < 0) {
/* Something is very wrong, but I'm not sure how to handle it. Running
around like a headless chicken is ill-advised, so let's pretend this
never happened. */
pthread_mutex_unlock(&games[game_id].state_lock);
return;
}
games[game_id].players[slot] = EMPTY_SLOT;
games[game_id].slots_filled--;
/* If there are players left, kill the player. */
if (games[game_id].slots_filled > 0) {
games[game_id].data.players[slot].lives = 0;
games[game_id].data.players[slot].respawning = 1;
}
/* If that was the last player, end the game. */
else {
games[game_id].status = GAME_FREE;
cancel_requests(game_id);
}
pthread_mutex_unlock(&games[game_id].state_lock);
}
/* Process CMD_SETUP_GAME. */
static void process_setup_game(int id, int sockfd, char* buffer) {
int game_id, game_mode, slots_total, slot;
char name[NAME_LEN + 1], tempbuf[8];
/* Load the game data and try to fetch a free ID. */
unserialize_game_setup(buffer, name, &game_mode, &slots_total);
pthread_mutex_lock(&new_game_lock);
if ((game_id = get_free_game_id()) < 0) {
pthread_mutex_unlock(&new_game_lock);
SAFE_TRANSMIT(id, sockfd, CMD_ERROR, ERR_FULL);
return;
}
/* Populate the game's struct. */
games[game_id].slots_total = slots_total;
games[game_id].slots_filled = 1;
games[game_id].players[0] = id;
for (slot = 1; slot < slots_total; slot++)
games[game_id].players[slot] = EMPTY_SLOT;
strcpy(games[game_id].name, name);
games[game_id].mode = game_mode;
games[game_id].status = GAME_WAITING;
pthread_mutex_unlock(&new_game_lock);
/* Populate the game's admin's struct and inform them of the creation. */
clients[id].game = game_id;
clients[id].status = CLIENT_WAITING;
snprintf(tempbuf, 8, "%d", id);
SAFE_TRANSMIT(id, sockfd, CMD_PLAYER_JOIN, tempbuf);
}
/* Process CMD_JOIN_GAME. */
static void process_join_game(int id, int sockfd, char* buffer) {
int game_id, admin;
char tempbuf[8];
/* Check for an old pending request; check for validity of new one. */
if (clients[id].request != NO_REQUEST) {
SAFE_TRANSMIT(id, sockfd, CMD_ERROR, ERR_ALREADY_PENDING);
return;
}
game_id = atoi(buffer);
if (game_id < 0 || game_id >= MAX_GAMES) {
SAFE_TRANSMIT(id, sockfd, CMD_ERROR, ERR_BAD_ID);
return;
}
/* Reject if game isn't waiting for new players, or if it's full. */
pthread_mutex_lock(&games[game_id].state_lock);
if (games[game_id].status != GAME_WAITING) {
SAFE_TRANSMIT(id, sockfd, CMD_ERROR, (games[game_id].status == GAME_PLAYING) ? ERR_GAME_STARTED : ERR_BAD_ID);
return;
}
if (games[game_id].slots_filled >= games[game_id].slots_total) {
SAFE_TRANSMIT(id, sockfd, CMD_ERROR, ERR_GAME_FULL);
return;
}
/* Inform the game admin of the new request. */
clients[id].request = game_id;
admin = games[game_id].players[0];
snprintf(tempbuf, 8, "%d", id);
SAFE_TRANSMIT2(admin, CMD_NEW_REQUEST, tempbuf);
pthread_mutex_unlock(&games[game_id].state_lock);
}
/* Process CMD_CANCEL_REQ. */
static void process_cancel_req(int id, int sockfd) {
int game_id = clients[id].request, admin;
char tempbuf[8];
/* Ensure the client has a pending request to cancel. */
if (game_id == -1) {
SAFE_TRANSMIT(id, sockfd, CMD_ERROR, ERR_NO_REQUEST);
return;
}
/* Invalidate the request and inform the admin if necessary. */
clients[id].request = NO_REQUEST;
pthread_mutex_lock(&games[game_id].state_lock);
if (games[game_id].status == GAME_WAITING) {
admin = games[game_id].players[0];
snprintf(tempbuf, 8, "%d", id);
SAFE_TRANSMIT2(admin, CMD_CANCEL_REQ, tempbuf);
}
pthread_mutex_unlock(&games[game_id].state_lock);
}
/* Process CMD_ACCEPT_REQ. */
static void process_accept_req(int id, int sockfd, char* buffer) {
int game_id = clients[id].game, requester, slot, player;
char tempbuf[8], tempbuf2[8];
/* Only admins can accept requests; ensure request is valid. */
if (id != games[game_id].players[0]) {
SAFE_TRANSMIT(id, sockfd, CMD_ERROR, ERR_NOT_ADMIN);
return;
}
requester = atoi(buffer);
if (clients[requester].request != game_id) {
SAFE_TRANSMIT(id, sockfd, CMD_ERROR, ERR_NO_REQUEST);
return;
}
/* Remove the pending request and inform the requester; update struct. */
clients[requester].request = NO_REQUEST;
SAFE_TRANSMIT2(requester, CMD_ACCEPT_REQ, NULL);
clients[requester].status = CLIENT_WAITING;
clients[requester].game = game_id;
/* Inform current players of the new guy and vice versa. */
snprintf(tempbuf, 8, "%d", requester);
pthread_mutex_lock(&games[game_id].state_lock);
for (slot = 0; slot < games[game_id].slots_total; slot++) {
player = games[game_id].players[slot];
if (player == EMPTY_SLOT)
continue;
snprintf(tempbuf2, 8, "%d", player);
SAFE_TRANSMIT2(player, CMD_PLAYER_JOIN, tempbuf);
SAFE_TRANSMIT2(requester, CMD_PLAYER_JOIN, tempbuf2);
}
SAFE_TRANSMIT2(requester, CMD_PLAYER_JOIN, tempbuf);
/* Fill an empty slot with the new player. */
for (slot = 0; slot < games[game_id].slots_total; slot++) {
if (games[game_id].players[slot] == EMPTY_SLOT) {
games[game_id].players[slot] = requester;
break;
}
}
games[game_id].slots_filled++;
/* If we have enough players now, start the game. */
if (games[game_id].slots_filled >= games[game_id].slots_total) {
games[game_id].status = GAME_PLAYING;
/* Inform players of the game start. */
for (slot = 0; slot < games[game_id].slots_total; slot++) {
player = games[game_id].players[slot];
if (player == EMPTY_SLOT)
continue;
clients[player].status = CLIENT_IN_GAME;
snprintf(tempbuf2, 8, "%d", slot);
SAFE_TRANSMIT2(player, CMD_GAME_START, tempbuf2);
}
cancel_requests(game_id);
start_game_thread(game_id);
}
pthread_mutex_unlock(&games[game_id].state_lock);
}
/* Process CMD_REJECT_REQ. */
static void process_reject_req(int id, int sockfd, char* buffer) {
int game_id = clients[id].game, requester;
/* Only admins can accept requests; ensure request is valid. */
if (id != games[game_id].players[0]) {
SAFE_TRANSMIT(id, sockfd, CMD_ERROR, ERR_NOT_ADMIN);
return;
}
requester = atoi(buffer);
if (clients[requester].request != game_id) {
SAFE_TRANSMIT(id, sockfd, CMD_ERROR, ERR_NO_REQUEST);
return;
}
/* Remove the pending request and inform the requester. */
clients[requester].request = NO_REQUEST;
SAFE_TRANSMIT2(requester, CMD_REJECT_REQ, NULL);
}
/* Process CMD_PLAYER_PART. */
static void process_player_part(int id) {
clients[id].status = CLIENT_IDLE;
remove_player(id, clients[id].game);
}
/* Process CMD_INPUT. */
static void process_input(int id, int sockfd, char* buffer) {
int game_id = clients[id].game;
input_t* input = malloc(sizeof(input_t));
/* Lock the input buffer, create a new node, and push it to the top. */
pthread_mutex_lock(&games[game_id].input_buffer.lock);
input->player = id;
input->action = atoi(buffer);
input->next = games[game_id].input_buffer.first;
games[game_id].input_buffer.first = input;
pthread_mutex_unlock(&games[game_id].input_buffer.lock);
}
/* Clean up data involving a particular client after their socket is closed. */
static void cleanup_client(int id) {
int game_id, admin;
char tempbuf[8];
/* If client has a pending request: invalidate it and inform admin. */
if (clients[id].status == CLIENT_IDLE && clients[id].request != -1) {
game_id = clients[id].request;
clients[id].request = NO_REQUEST;
pthread_mutex_lock(&games[game_id].state_lock);
if (games[game_id].status == GAME_WAITING) {
admin = games[game_id].players[0];
snprintf(tempbuf, 8, "%d", id);
SAFE_TRANSMIT2(admin, CMD_CANCEL_REQ, tempbuf);
}
pthread_mutex_unlock(&games[game_id].state_lock);
}
/* If client is in a game, act as if they've parted. */
else if (clients[id].status == CLIENT_WAITING || clients[id].status == CLIENT_IN_GAME)
remove_player(id, clients[id].game);
clients[id].status = CLIENT_FREE;
}
/* Handle a connection with a client. This runs in its own thread. */
static void* handle_client(void* arg) {
char* buffer, databuf[1024];
int id = *((int*) arg), sockfd = clients[id].sockfd, command;
if (receive(sockfd, &command, &buffer) < 0)
goto cleanup;
switch (command) {
case CMD_CONNECT:
if (strlen(buffer) < 2 || strlen(buffer) > NAME_LEN) {
free(buffer);
transmit(sockfd, CMD_QUIT, ERR_BAD_NAME);
goto cleanup;
}
strcpy(clients[id].name, buffer);
free(buffer);
clients[id].status = CLIENT_IDLE;
snprintf(databuf, 1024, "%d", id);
transmit(sockfd, CMD_CONNECT, databuf);
break;
case CMD_GETPID:
free(buffer);
if (is_local_client(id)) {
snprintf(databuf, 1024, "%d", getpid());
write(sockfd, databuf, strlen(databuf));
}
else
transmit(sockfd, CMD_QUIT, ERR_UNAUTHORIZED);
goto cleanup;
case CMD_STATUS:
free(buffer);
if (is_local_client(id)) {
serialize_status_data(&clients[0], &games[0], databuf);
write(sockfd, databuf, strlen(databuf));
}
else
transmit(sockfd, CMD_QUIT, ERR_UNAUTHORIZED);
goto cleanup;
default:
free(buffer);
transmit(sockfd, CMD_QUIT, ERR_INVALID);
goto cleanup;
}
while (1) {
if (receive(sockfd, &command, &buffer) < 0)
goto cleanup;
switch (command) {
case CMD_LOBBY_INFO:
ENFORCE_CONTEXT(CLIENT_IDLE);
free(buffer);
serialize_lobby_info(&clients[0], &games[0], &buffer);
SAFE_TRANSMIT(id, sockfd, CMD_LOBBY_INFO, buffer);
break;
case CMD_SETUP_GAME:
ENFORCE_CONTEXT(CLIENT_IDLE);
process_setup_game(id, sockfd, buffer);
break;
case CMD_JOIN_GAME:
ENFORCE_CONTEXT(CLIENT_IDLE);
process_join_game(id, sockfd, buffer);
break;
case CMD_CANCEL_REQ:
ENFORCE_CONTEXT(CLIENT_IDLE);
process_cancel_req(id, sockfd);
break;
case CMD_ACCEPT_REQ:
ENFORCE_CONTEXT(CLIENT_WAITING);
process_accept_req(id, sockfd, buffer);
break;
case CMD_REJECT_REQ:
ENFORCE_CONTEXT(CLIENT_WAITING);
process_reject_req(id, sockfd, buffer);
break;
case CMD_PLAYER_PART:
ENFORCE_CONTEXT(CLIENT_WAITING && clients[id].status != CLIENT_IN_GAME);
process_player_part(id);
break;
case CMD_INPUT:
ENFORCE_CONTEXT(CLIENT_IN_GAME);
process_input(id, sockfd, buffer);
break;
default:
free(buffer);
SAFE_TRANSMIT(id, sockfd, CMD_QUIT, ERR_INVALID);
goto cleanup;
}
free(buffer);
}
cleanup:
close(sockfd);
cleanup_client(id);
return NULL;
}
/* Main server loop which listens for and handles connections. */
static void serve() {
struct sockaddr_in client_addr;
socklen_t client_len;
int client_fd, id;
pthread_attr_t attr;
client_len = sizeof(client_addr);
while (1) {
if ((client_fd = accept(master_sockfd, (struct sockaddr*) &client_addr, &client_len)) < 0)
stop_server(1);
if ((id = get_free_client_id()) < 0) {
transmit(client_fd, CMD_QUIT, ERR_FULL);
close(client_fd);
}
clients[id].status = CLIENT_CONNECTING;
clients[id].sockfd = client_fd;
clients[id].addr = client_addr;
pthread_attr_init(&attr);
pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
if (pthread_create(&clients[id].thread, &attr, handle_client, (void*) &id) < 0) {
pthread_attr_destroy(&attr);
transmit(client_fd, CMD_QUIT, ERR_SERVER_STOPPING);
clients[id].status = CLIENT_FREE;
stop_server(1);
}
pthread_attr_destroy(&attr);
}
}
/* ------------------------------- Commands -------------------------------- */
static void do_help(char* name) {
printf("%s [status|start|stop]\n", name);
}
static void do_status(void) {
int sockfd = make_connection("localhost");
int n_clients, nc_max, nc_connecting, nc_idle, nc_waiting, nc_in_game,
n_games, ng_max, ng_waiting, ng_playing;
char resp[1024];
printf("Terminvaders server: ");
if (sockfd < 0) {
printf("offline.\n");
return;
}
printf("running on port %d.\n", PORT);
if (transmit(sockfd, CMD_STATUS, NULL) < 0)
return;
read(sockfd, resp, 1024);
close(sockfd);
sscanf(resp, "%d/%d (%d/%d/%d/%d)\n%d/%d (%d/%d)", &n_clients, &nc_max,
&nc_connecting, &nc_idle, &nc_waiting, &nc_in_game, &n_games,
&ng_max, &ng_waiting, &ng_playing);
printf("%d users connected (%d max)\n", n_clients, nc_max);
if (nc_connecting > 0)
printf(" %d users connecting\n", nc_connecting);
if (nc_idle > 0)
printf(" %d users idling in the lobby\n", nc_idle);
if (nc_waiting > 0)
printf(" %d users waiting for a game to start\n", nc_waiting);
if (nc_in_game > 0)
printf(" %d users in a game\n", nc_in_game);
printf("%d games active (%d max)\n", n_games, ng_max);
if (ng_waiting > 0)
printf(" %d games waiting for players\n", ng_waiting);
if (ng_playing > 0)
printf(" %d games in progress\n", ng_playing);
}
static void do_start(void) {
if (is_running()) {
printf("Error: the server is already running!\n");
exit(1);
}
start_server();
printf("Terminvaders server listening on port %d.\n", PORT);
printf("Daemonizing... ");
fflush(stdout);
daemonize();
serve();
}
static void do_stop(void) {
pid_t pid;
if (!is_running()) {
printf("Error: the server not running!\n");
exit(1);
}
printf("Stopping server... ");
fflush(stdout);
if ((pid = get_server_pid()) < 0) {
perror("error: couldn't get PID of server");
exit(1);
}
if (kill(pid, SIGTERM)) {
if (errno == EPERM)
printf("error: no permission to kill(%d).\n", pid);
else
printf("error: can't kill(%d). Already stopped?\n", pid);
exit(1);
}
while (1) { /* Poll until server quits. */
if (kill(pid, 0)) {
if (errno == ESRCH) {
printf("stopped.\n");
return;
}
perror("error");
exit(1);
}
usleep(500); /* Try again in half a second. */
}
}
/* --------------------------------- Main ---------------------------------- */
int main(int argc, char* argv[]) {
if (argc < 2)
do_help(argv[0]);
else if (!strcmp(argv[1], "status"))
do_status();
else if (!strcmp(argv[1], "start"))
do_start();
else if (!strcmp(argv[1], "stop"))
do_stop();
else {
do_help(argv[0]);
return 1;
}
return 0;
}