pbx.c

	/* id is zero is a callback without extension */
	if (!id) {
		cbprev = NULL;
		cblist = statecbs;
		while (cblist) {
	 		if (cblist->callback == callback) {
				if (!cbprev)
		    			statecbs = cblist->next;
				else
		    			cbprev->next = cblist->next;

				free(cblist);

	        		ast_mutex_unlock(&hintlock);
				return 0;
	    		}
	    		cbprev = cblist;
	    		cblist = cblist->next;
		}

		ast_mutex_lock(&hintlock);
		return -1;
	}

	/* id greater than zero is a callback with extension */
	/* Find the callback based on ID */
	list = hints;
	while (list) {
		cblist = list->callbacks;
		cbprev = NULL;
		while (cblist) {
	    		if (cblist->id==id) {
				if (!cbprev)
		    			list->callbacks = cblist->next;		
				else
		    			cbprev->next = cblist->next;
		
				free(cblist);
		
				ast_mutex_unlock(&hintlock);
				return 0;		
	    		}		
	    		cbprev = cblist;				
	    		cblist = cblist->next;
		}
		list = list->next;
	}

	ast_mutex_unlock(&hintlock);
	return -1;
}

/*--- ast_add_hint: Add hint to hint list, check initial extension state */
static int ast_add_hint(struct ast_exten *e)
{
	struct ast_hint *list;

	if (!e) 
		return -1;

	ast_mutex_lock(&hintlock);
	list = hints;        

	/* Search if hint exists, do nothing */
	while (list) {
		if (list->exten == e) {
			ast_mutex_unlock(&hintlock);
			if (option_debug > 1)
				ast_log(LOG_DEBUG, "HINTS: Not re-adding existing hint %s: %s\n", ast_get_extension_name(e), ast_get_extension_app(e));
			return -1;
		}
		list = list->next;    
	}

	if (option_debug > 1)
		ast_log(LOG_DEBUG, "HINTS: Adding hint %s: %s\n", ast_get_extension_name(e), ast_get_extension_app(e));

	list = malloc(sizeof(struct ast_hint));
	if (!list) {
		ast_mutex_unlock(&hintlock);
		if (option_debug > 1)
			ast_log(LOG_DEBUG, "HINTS: Out of memory...\n");
		return -1;
	}
	/* Initialize and insert new item at the top */
	memset(list, 0, sizeof(struct ast_hint));
	list->exten = e;
	list->laststate = ast_extension_state2(e);
	list->next = hints;
	hints = list;

	ast_mutex_unlock(&hintlock);
	return 0;
}

/*--- ast_change_hint: Change hint for an extension */
static int ast_change_hint(struct ast_exten *oe, struct ast_exten *ne)
{ 
	struct ast_hint *list;

	ast_mutex_lock(&hintlock);
	list = hints;

	while(list) {
		if (list->exten == oe) {
	    		list->exten = ne;
			ast_mutex_unlock(&hintlock);	
			return 0;
		}
		list = list->next;
	}
	ast_mutex_unlock(&hintlock);

	return -1;
}

/*--- ast_remove_hint: Remove hint from extension */
static int ast_remove_hint(struct ast_exten *e)
{
	/* Cleanup the Notifys if hint is removed */
	struct ast_hint *list, *prev = NULL;
	struct ast_state_cb *cblist, *cbprev;

	if (!e) 
		return -1;

	ast_mutex_lock(&hintlock);

	list = hints;    
	while(list) {
		if (list->exten==e) {
			cbprev = NULL;
			cblist = list->callbacks;
			while (cblist) {
				/* Notify with -1 and remove all callbacks */
				cbprev = cblist;	    
				cblist = cblist->next;
				cbprev->callback(list->exten->parent->name, list->exten->exten, -1, cbprev->data);
				free(cbprev);
	    		}
	    		list->callbacks = NULL;

	    		if (!prev)
				hints = list->next;
	    		else
				prev->next = list->next;
	    		free(list);
	    
			ast_mutex_unlock(&hintlock);
			return 0;
		} else {
			prev = list;
			list = list->next;    
		}
	}

	ast_mutex_unlock(&hintlock);
	return -1;
}


/*--- ast_get_hint: Get hint for channel */
int ast_get_hint(char *hint, int hintsize, char *name, int namesize, struct ast_channel *c, const char *context, const char *exten)
{
	struct ast_exten *e;
	void *tmp;
	e = ast_hint_extension(c, context, exten);
	if (e) {
		if (hint) 
		    strncpy(hint, ast_get_extension_app(e), hintsize - 1);
		if (name) {
			tmp = ast_get_extension_app_data(e);
			if (tmp)
				strncpy(name, (char *)tmp, namesize - 1);
		}
	    return -1;
	}
	return 0;	
}

int ast_exists_extension(struct ast_channel *c, const char *context, const char *exten, int priority, const char *callerid) 
{
	return pbx_extension_helper(c, NULL, context, exten, priority, NULL, callerid, HELPER_EXISTS);
}

int ast_findlabel_extension(struct ast_channel *c, const char *context, const char *exten, const char *label, const char *callerid) 
{
	return pbx_extension_helper(c, NULL, context, exten, 0, label, callerid, HELPER_FINDLABEL);
}

int ast_findlabel_extension2(struct ast_channel *c, struct ast_context *con, const char *exten, const char *label, const char *callerid) 
{
	return pbx_extension_helper(c, con, NULL, exten, 0, label, callerid, HELPER_FINDLABEL);
}

int ast_canmatch_extension(struct ast_channel *c, const char *context, const char *exten, int priority, const char *callerid)
{
	return pbx_extension_helper(c, NULL, context, exten, priority, NULL, callerid, HELPER_CANMATCH);
}

int ast_matchmore_extension(struct ast_channel *c, const char *context, const char *exten, int priority, const char *callerid)
{
	return pbx_extension_helper(c, NULL, context, exten, priority, NULL, callerid, HELPER_MATCHMORE);
}

int ast_spawn_extension(struct ast_channel *c, const char *context, const char *exten, int priority, const char *callerid) 
{
	return pbx_extension_helper(c, NULL, context, exten, priority, NULL, callerid, HELPER_SPAWN);
}

int ast_exec_extension(struct ast_channel *c, const char *context, const char *exten, int priority, const char *callerid) 
{
	return pbx_extension_helper(c, NULL, context, exten, priority, NULL, callerid, HELPER_EXEC);
}

int ast_pbx_run(struct ast_channel *c)
{
	int firstpass = 1;
	char digit;
	char exten[256];
	int pos;
	int waittime;
	int res=0;

	/* A little initial setup here */
	if (c->pbx)
		ast_log(LOG_WARNING, "%s already has PBX structure??\n", c->name);
	c->pbx = malloc(sizeof(struct ast_pbx));
	if (!c->pbx) {
		ast_log(LOG_ERROR, "Out of memory\n");
		return -1;
	}
	if (c->amaflags) {
		if (!c->cdr) {
			c->cdr = ast_cdr_alloc();
			if (!c->cdr) {
				ast_log(LOG_WARNING, "Unable to create Call Detail Record\n");
				free(c->pbx);
				return -1;
			}
			ast_cdr_init(c->cdr, c);
		}
	}
	memset(c->pbx, 0, sizeof(struct ast_pbx));
	/* Set reasonable defaults */
	c->pbx->rtimeout = 10;
	c->pbx->dtimeout = 5;

	/* Start by trying whatever the channel is set to */
	if (!ast_exists_extension(c, c->context, c->exten, c->priority, c->cid.cid_num)) {
		/* JK02: If not successfull fall back to 's' */
		if (option_verbose > 1)
			ast_verbose( VERBOSE_PREFIX_2 "Starting %s at %s,%s,%d failed so falling back to exten 's'\n", c->name, c->context, c->exten, c->priority);
		strncpy(c->exten, "s", sizeof(c->exten)-1);
		if (!ast_exists_extension(c, c->context, c->exten, c->priority, c->cid.cid_num)) {
			/* JK02: And finally back to default if everything else failed */
			if (option_verbose > 1)
				ast_verbose( VERBOSE_PREFIX_2 "Starting %s at %s,%s,%d still failed so falling back to context 'default'\n", c->name, c->context, c->exten, c->priority);
			strncpy(c->context, "default", sizeof(c->context)-1);
		}
		c->priority = 1;
	}
	if (c->cdr && !c->cdr->start.tv_sec && !c->cdr->start.tv_usec)
		ast_cdr_start(c->cdr);
	for(;;) {
		pos = 0;
		digit = 0;
		while(ast_exists_extension(c, c->context, c->exten, c->priority, c->cid.cid_num)) {
			memset(exten, 0, sizeof(exten));
			if ((res = ast_spawn_extension(c, c->context, c->exten, c->priority, c->cid.cid_num))) {
				/* Something bad happened, or a hangup has been requested. */
				if (((res >= '0') && (res <= '9')) || ((res >= 'A') && (res <= 'F')) ||
					(res == '*') || (res == '#')) {
					ast_log(LOG_DEBUG, "Oooh, got something to jump out with ('%c')!\n", res);
					memset(exten, 0, sizeof(exten));
					pos = 0;
					exten[pos++] = digit = res;
					break;
				}
				switch(res) {
				case AST_PBX_KEEPALIVE:
					if (option_debug)
						ast_log(LOG_DEBUG, "Spawn extension (%s,%s,%d) exited KEEPALIVE on '%s'\n", c->context, c->exten, c->priority, c->name);
					else if (option_verbose > 1)
						ast_verbose( VERBOSE_PREFIX_2 "Spawn extension (%s, %s, %d) exited KEEPALIVE on '%s'\n", c->context, c->exten, c->priority, c->name);
					goto out;
					break;
				default:
					if (option_debug)
						ast_log(LOG_DEBUG, "Spawn extension (%s,%s,%d) exited non-zero on '%s'\n", c->context, c->exten, c->priority, c->name);
					else if (option_verbose > 1)
						ast_verbose( VERBOSE_PREFIX_2 "Spawn extension (%s, %s, %d) exited non-zero on '%s'\n", c->context, c->exten, c->priority, c->name);
					if (c->_softhangup == AST_SOFTHANGUP_ASYNCGOTO) {
						c->_softhangup =0;
						break;
					}
					/* atimeout */
					if (c->_softhangup == AST_SOFTHANGUP_TIMEOUT) {
						break;
					}

					if (c->cdr) {
						ast_cdr_update(c);
					}
					goto out;
				}
			}
			if ((c->_softhangup == AST_SOFTHANGUP_TIMEOUT) && (ast_exists_extension(c,c->context,"T",1,c->cid.cid_num))) {
				strncpy(c->exten,"T",sizeof(c->exten) - 1);
				/* If the AbsoluteTimeout is not reset to 0, we'll get an infinite loop */
				c->whentohangup = 0;
				c->priority = 0;
				c->_softhangup &= ~AST_SOFTHANGUP_TIMEOUT;
			} else if (c->_softhangup) {
				ast_log(LOG_DEBUG, "Extension %s, priority %d returned normally even though call was hung up\n",
					c->exten, c->priority);
				goto out;
			}
			firstpass = 0;
			c->priority++;
		}
		if (!ast_exists_extension(c, c->context, c->exten, 1, c->cid.cid_num)) {
			/* It's not a valid extension anymore */
			if (ast_exists_extension(c, c->context, "i", 1, c->cid.cid_num)) {
				if (option_verbose > 2)
					ast_verbose(VERBOSE_PREFIX_3 "Sent into invalid extension '%s' in context '%s' on %s\n", c->exten, c->context, c->name);
				pbx_builtin_setvar_helper(c, "INVALID_EXTEN", c->exten);
				strncpy(c->exten, "i", sizeof(c->exten)-1);
				c->priority = 1;
			} else {
				ast_log(LOG_WARNING, "Channel '%s' sent into invalid extension '%s' in context '%s', but no invalid handler\n",
					c->name, c->exten, c->context);
				goto out;
			}
		} else if (c->_softhangup == AST_SOFTHANGUP_TIMEOUT) {
			/* If we get this far with AST_SOFTHANGUP_TIMEOUT, then we know that the "T" extension is next. */
			c->_softhangup = 0;
		} else {
			/* Done, wait for an extension */
			waittime = 0;
			if (digit)
				waittime = c->pbx->dtimeout;
			else if (!autofallthrough)
				waittime = c->pbx->rtimeout;
			if (waittime) {
				while (ast_matchmore_extension(c, c->context, exten, 1, c->cid.cid_num)) {
					/* As long as we're willing to wait, and as long as it's not defined, 
					   keep reading digits until we can't possibly get a right answer anymore.  */
					digit = ast_waitfordigit(c, waittime * 1000);
					if (c->_softhangup == AST_SOFTHANGUP_ASYNCGOTO) {
						c->_softhangup = 0;
					} else {
						if (!digit)
							/* No entry */
							break;
						if (digit < 0)
							/* Error, maybe a  hangup */
							goto out;
						exten[pos++] = digit;
						waittime = c->pbx->dtimeout;
					}
				}
				if (ast_exists_extension(c, c->context, exten, 1, c->cid.cid_num)) {
					/* Prepare the next cycle */
					strncpy(c->exten, exten, sizeof(c->exten)-1);
					c->priority = 1;
				} else {
					/* No such extension */
					if (!ast_strlen_zero(exten)) {
						/* An invalid extension */
						if (ast_exists_extension(c, c->context, "i", 1, c->cid.cid_num)) {
							if (option_verbose > 2)
								ast_verbose( VERBOSE_PREFIX_3 "Invalid extension '%s' in context '%s' on %s\n", exten, c->context, c->name);
							pbx_builtin_setvar_helper(c, "INVALID_EXTEN", exten);
							strncpy(c->exten, "i", sizeof(c->exten)-1);
							c->priority = 1;
						} else {
							ast_log(LOG_WARNING, "Invalid extension '%s', but no rule 'i' in context '%s'\n", exten, c->context);
							goto out;
						}
					} else {
						/* A simple timeout */
						if (ast_exists_extension(c, c->context, "t", 1, c->cid.cid_num)) {
							if (option_verbose > 2)
								ast_verbose( VERBOSE_PREFIX_3 "Timeout on %s\n", c->name);
							strncpy(c->exten, "t", sizeof(c->exten)-1);
							c->priority = 1;
						} else {
							ast_log(LOG_WARNING, "Timeout, but no rule 't' in context '%s'\n", c->context);
							goto out;
						}
					}	
				}
				if (c->cdr) {
					if (option_verbose > 2)
						ast_verbose(VERBOSE_PREFIX_2 "CDR updated on %s\n",c->name);	
					ast_cdr_update(c);
			    }
			} else {
				char *status;
				status = pbx_builtin_getvar_helper(c, "DIALSTATUS");
				if (!status)
					status = "UNKNOWN";
				if (option_verbose > 2)
					ast_verbose(VERBOSE_PREFIX_2 "Auto fallthrough, channel '%s' status is '%s'\n", c->name, status);
				if (!strcasecmp(status, "CONGESTION"))
					res = pbx_builtin_congestion(c, "10");
				else if (!strcasecmp(status, "CHANUNAVAIL"))
					res = pbx_builtin_congestion(c, "10");
				else if (!strcasecmp(status, "BUSY"))
					res = pbx_builtin_busy(c, "10");
				goto out;
			}
		}
	}
	if (firstpass) 
		ast_log(LOG_WARNING, "Don't know what to do with '%s'\n", c->name);
out:
	if ((res != AST_PBX_KEEPALIVE) && ast_exists_extension(c, c->context, "h", 1, c->cid.cid_num)) {
		c->exten[0] = 'h';
		c->exten[1] = '\0';
		c->priority = 1;
		while(ast_exists_extension(c, c->context, c->exten, c->priority, c->cid.cid_num)) {
			if ((res = ast_spawn_extension(c, c->context, c->exten, c->priority, c->cid.cid_num))) {
				/* Something bad happened, or a hangup has been requested. */
				if (option_debug)
					ast_log(LOG_DEBUG, "Spawn extension (%s,%s,%d) exited non-zero on '%s'\n", c->context, c->exten, c->priority, c->name);
				else if (option_verbose > 1)
					ast_verbose( VERBOSE_PREFIX_2 "Spawn extension (%s, %s, %d) exited non-zero on '%s'\n", c->context, c->exten, c->priority, c->name);
				break;
			}
			c->priority++;
		}
	}

	pbx_destroy(c->pbx);
	c->pbx = NULL;
	if (res != AST_PBX_KEEPALIVE)
		ast_hangup(c);
	return 0;
}

static void *pbx_thread(void *data)
{
	/* Oh joyeous kernel, we're a new thread, with nothing to do but
	   answer this channel and get it going.  The setjmp stuff is fairly
	   confusing, but necessary to get smooth transitions between
	   the execution of different applications (without the use of
	   additional threads) */
	struct ast_channel *c = data;
	ast_pbx_run(c);
	pthread_exit(NULL);
	return NULL;
}

int ast_pbx_start(struct ast_channel *c)
{
	pthread_t t;
	pthread_attr_t attr;
	if (!c) {
		ast_log(LOG_WARNING, "Asked to start thread on NULL channel?\n");
		return -1;
	}
	   
	/* Start a new thread, and get something handling this channel. */
	pthread_attr_init(&attr);
	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
	if (ast_pthread_create(&t, &attr, pbx_thread, c)) {
		ast_log(LOG_WARNING, "Failed to create new channel thread\n");
		return -1;
	}
	return 0;
}

int pbx_set_autofallthrough(int newval)
{
	int oldval;
	oldval = autofallthrough;
	if (oldval != newval)
		autofallthrough = newval;
	return oldval;
}

/*
 * This function locks contexts list by &conlist, search for the right context
 * structure, leave context list locked and call ast_context_remove_include2
 * which removes include, unlock contexts list and return ...
 */
int ast_context_remove_include(const char *context, const char *include, const char *registrar)
{
	struct ast_context *c;

	if (ast_lock_contexts()) return -1;

	/* walk contexts and search for the right one ...*/
	c = ast_walk_contexts(NULL);
	while (c) {
		/* we found one ... */
		if (!strcmp(ast_get_context_name(c), context)) {
			int ret;
			/* remove include from this context ... */	
			ret = ast_context_remove_include2(c, include, registrar);

			ast_unlock_contexts();

			/* ... return results */
			return ret;
		}
		c = ast_walk_contexts(c);
	}

	/* we can't find the right one context */
	ast_unlock_contexts();
	return -1;
}

/*
 * When we call this function, &conlock lock must be locked, because when
 * we giving *con argument, some process can remove/change this context
 * and after that there can be segfault.
 *
 * This function locks given context, removes include, unlock context and
 * return.
 */
int ast_context_remove_include2(struct ast_context *con, const char *include, const char *registrar)
{
	struct ast_include *i, *pi = NULL;

	if (ast_mutex_lock(&con->lock)) return -1;

	/* walk includes */
	i = con->includes;
	while (i) {
		/* find our include */
		if (!strcmp(i->name, include) && 
			(!registrar || !strcmp(i->registrar, registrar))) {
			/* remove from list */
			if (pi)
				pi->next = i->next;
			else
				con->includes = i->next;
			/* free include and return */
			free(i);
			ast_mutex_unlock(&con->lock);
			return 0;
		}
		pi = i;
		i = i->next;
	}

	/* we can't find the right include */
	ast_mutex_unlock(&con->lock);
	return -1;
}

/*
 * This function locks contexts list by &conlist, search for the rigt context
 * structure, leave context list locked and call ast_context_remove_switch2
 * which removes switch, unlock contexts list and return ...
 */
int ast_context_remove_switch(const char *context, const char *sw, const char *data, const char *registrar)
{
	struct ast_context *c;

	if (ast_lock_contexts()) return -1;

	/* walk contexts and search for the right one ...*/
	c = ast_walk_contexts(NULL);
	while (c) {
		/* we found one ... */
		if (!strcmp(ast_get_context_name(c), context)) {
			int ret;
			/* remove switch from this context ... */	
			ret = ast_context_remove_switch2(c, sw, data, registrar);

			ast_unlock_contexts();

			/* ... return results */
			return ret;
		}
		c = ast_walk_contexts(c);
	}

	/* we can't find the right one context */
	ast_unlock_contexts();
	return -1;
}

/*
 * When we call this function, &conlock lock must be locked, because when
 * we giving *con argument, some process can remove/change this context
 * and after that there can be segfault.
 *
 * This function locks given context, removes switch, unlock context and
 * return.
 */
int ast_context_remove_switch2(struct ast_context *con, const char *sw, const char *data, const char *registrar)
{
	struct ast_sw *i, *pi = NULL;

	if (ast_mutex_lock(&con->lock)) return -1;

	/* walk switchs */
	i = con->alts;
	while (i) {
		/* find our switch */
		if (!strcmp(i->name, sw) && !strcmp(i->data, data) && 
			(!registrar || !strcmp(i->registrar, registrar))) {
			/* remove from list */
			if (pi)
				pi->next = i->next;
			else
				con->alts = i->next;
			/* free switch and return */
			free(i);
			ast_mutex_unlock(&con->lock);
			return 0;
		}
		pi = i;
		i = i->next;
	}

	/* we can't find the right switch */
	ast_mutex_unlock(&con->lock);
	return -1;
}

/*
 * This functions lock contexts list, search for the right context,
 * call ast_context_remove_extension2, unlock contexts list and return.
 * In this function we are using
 */
int ast_context_remove_extension(const char *context, const char *extension, int priority, const char *registrar)
{
	struct ast_context *c;

	if (ast_lock_contexts()) return -1;

	/* walk contexts ... */
	c = ast_walk_contexts(NULL);
	while (c) {
		/* ... search for the right one ... */
		if (!strcmp(ast_get_context_name(c), context)) {
			/* ... remove extension ... */
			int ret = ast_context_remove_extension2(c, extension, priority,
				registrar);
			/* ... unlock contexts list and return */
			ast_unlock_contexts();
			return ret;
		}
		c = ast_walk_contexts(c);
	}

	/* we can't find the right context */
	ast_unlock_contexts();
	return -1;
}

/*
 * When do you want to call this function, make sure that &conlock is locked,
 * because some process can handle with your *con context before you lock
 * it.
 *
 * This functionc locks given context, search for the right extension and
 * fires out all peer in this extensions with given priority. If priority
 * is set to 0, all peers are removed. After that, unlock context and
 * return.
 */
int ast_context_remove_extension2(struct ast_context *con, const char *extension, int priority, const char *registrar)
{
	struct ast_exten *exten, *prev_exten = NULL;

	if (ast_mutex_lock(&con->lock)) return -1;

	/* go through all extensions in context and search the right one ... */
	exten = con->root;
	while (exten) {

		/* look for right extension */
		if (!strcmp(exten->exten, extension) &&
			(!registrar || !strcmp(exten->registrar, registrar))) {
			struct ast_exten *peer;

			/* should we free all peers in this extension? (priority == 0)? */
			if (priority == 0) {
				/* remove this extension from context list */
				if (prev_exten)
					prev_exten->next = exten->next;
				else
					con->root = exten->next;

				/* fire out all peers */
				peer = exten; 
				while (peer) {
					exten = peer->peer;
					
					if (!peer->priority==PRIORITY_HINT) 
					    ast_remove_hint(peer);

					peer->datad(peer->data);
					free(peer);

					peer = exten;
				}

				ast_mutex_unlock(&con->lock);
				return 0;
			} else {
				/* remove only extension with exten->priority == priority */
				struct ast_exten *previous_peer = NULL;

				peer = exten;
				while (peer) {
					/* is this our extension? */
					if (peer->priority == priority &&
						(!registrar || !strcmp(peer->registrar, registrar) )) {
						/* we are first priority extension? */
						if (!previous_peer) {
							/* exists previous extension here? */
							if (prev_exten) {
								/* yes, so we must change next pointer in
								 * previous connection to next peer
								 */
								if (peer->peer) {
									prev_exten->next = peer->peer;
									peer->peer->next = exten->next;
								} else
									prev_exten->next = exten->next;
							} else {
								/* no previous extension, we are first
								 * extension, so change con->root ...
								 */
								if (peer->peer)
									con->root = peer->peer;
								else
									con->root = exten->next; 
							}
						} else {
							/* we are not first priority in extension */
							previous_peer->peer = peer->peer;
						}

						/* now, free whole priority extension */
						if (peer->priority==PRIORITY_HINT)
						    ast_remove_hint(peer);
						peer->datad(peer->data);
						free(peer);

						ast_mutex_unlock(&con->lock);
						return 0;
					} else {
						/* this is not right extension, skip to next peer */
						previous_peer = peer;
						peer = peer->peer;
					}
				}

				ast_mutex_unlock(&con->lock);
				return -1;
			}
		}

		prev_exten = exten;
		exten = exten->next;
	}

	/* we can't find right extension */
	ast_mutex_unlock(&con->lock);
	return -1;
}


int ast_register_application(const char *app, int (*execute)(struct ast_channel *, void *), const char *synopsis, const char *description)
{
	struct ast_app *tmp, *prev, *cur;
	char tmps[80];
	int length;
	length = sizeof(struct ast_app);
	length += strlen(app) + 1;
	if (ast_mutex_lock(&applock)) {
		ast_log(LOG_ERROR, "Unable to lock application list\n");
		return -1;
	}
	tmp = apps;
	while(tmp) {
		if (!strcasecmp(app, tmp->name)) {
			ast_log(LOG_WARNING, "Already have an application '%s'\n", app);
			ast_mutex_unlock(&applock);
			return -1;
		}
		tmp = tmp->next;
	}
	tmp = malloc(length);
	if (tmp) {
		memset(tmp, 0, length);
		strcpy(tmp->name, app);
		tmp->execute = execute;
		tmp->synopsis = synopsis;
		tmp->description = description;
		/* Store in alphabetical order */
		cur = apps;
		prev = NULL;
		while(cur) {
			if (strcasecmp(tmp->name, cur->name) < 0)
				break;
			prev = cur;
			cur = cur->next;
		}
		if (prev) {
			tmp->next = prev->next;
			prev->next = tmp;
		} else {
			tmp->next = apps;
			apps = tmp;
		}
	} else {
		ast_log(LOG_ERROR, "Out of memory\n");
		ast_mutex_unlock(&applock);
		return -1;
	}
	if (option_verbose > 1)
		ast_verbose( VERBOSE_PREFIX_2 "Registered application '%s'\n", term_color(tmps, tmp->name, COLOR_BRCYAN, 0, sizeof(tmps)));
	ast_mutex_unlock(&applock);
	return 0;
}

int ast_register_switch(struct ast_switch *sw)
{
	struct ast_switch *tmp, *prev=NULL;
	if (ast_mutex_lock(&switchlock)) {
		ast_log(LOG_ERROR, "Unable to lock switch lock\n");
		return -1;
	}
	tmp = switches;
	while(tmp) {
		if (!strcasecmp(tmp->name, sw->name))
			break;
		prev = tmp;
		tmp = tmp->next;
	}
	if (tmp) {	
		ast_mutex_unlock(&switchlock);
		ast_log(LOG_WARNING, "Switch '%s' already found\n", sw->name);
		return -1;
	}
	sw->next = NULL;
	if (prev) 
		prev->next = sw;
	else
		switches = sw;
	ast_mutex_unlock(&switchlock);
	return 0;
}

void ast_unregister_switch(struct ast_switch *sw)
{
	struct ast_switch *tmp, *prev=NULL;
	if (ast_mutex_lock(&switchlock)) {
		ast_log(LOG_ERROR, "Unable to lock switch lock\n");
		return;
	}
	tmp = switches;
	while(tmp) {
		if (tmp == sw) {
			if (prev)
				prev->next = tmp->next;
			else
				switches = tmp->next;
			tmp->next = NULL;
			break;			
		}
		prev = tmp;
		tmp = tmp->next;
	}
	ast_mutex_unlock(&switchlock);
}

/*
 * Help for CLI commands ...
 */
static char show_application_help[] = 
"Usage: show application <application> [<application> [<application> [...]]]\n"
"       Describes a particular application.\n";

static char show_functions_help[] =
"Usage: show functions\n"
"       List builtin functions accessable as $(function args)";

static char show_applications_help[] =
"Usage: show applications [{like|describing} <text>]\n"
"       List applications which are currently available.\n"
"       If 'like', <text> will be a substring of the app name\n"
"       If 'describing', <text> will be a substring of the description\n";

static char show_dialplan_help[] =
"Usage: show dialplan [exten@][context]\n"
"       Show dialplan\n";

static char show_switches_help[] = 
"Usage: show switches\n"
"       Show registered switches\n";

static char show_hints_help[] = 
"Usage: show hints\n"
"       Show registered hints\n";


/*
 * IMPLEMENTATION OF CLI FUNCTIONS IS IN THE SAME ORDER AS COMMANDS HELPS
 *
 */

/*
 * 'show application' CLI command implementation functions ...
 */

/*
 * There is a possibility to show informations about more than one
 * application at one time. You can type 'show application Dial Echo' and
 * you will see informations about these two applications ...
 */
static char *complete_show_application(char *line, char *word,
	int pos, int state)
{
	struct ast_app *a;
	int which = 0;

	/* try to lock applications list ... */
	if (ast_mutex_lock(&applock)) {
		ast_log(LOG_ERROR, "Unable to lock application list\n");
		return NULL;
	}

	/* ... walk all applications ... */
	a = apps; 
	while (a) {
		/* ... check if word matches this application ... */
		if (!strncasecmp(word, a->name, strlen(word))) {
			/* ... if this is right app serve it ... */
			if (++which > state) {
				char *ret = strdup(a->name);
				ast_mutex_unlock(&applock);
				return ret;
			}
		}
		a = a->next; 
	}

	/* no application match */
	ast_mutex_unlock(&applock);
	return NULL; 
}

static int handle_show_application(int fd, int argc, char *argv[])
{
	struct ast_app *a;
	int app, no_registered_app = 1;

	if (argc < 3) return RESULT_SHOWUSAGE;

	/* try to lock applications list ... */
	if (ast_mutex_lock(&applock)) {
		ast_log(LOG_ERROR, "Unable to lock application list\n");
		return -1;
	}

	/* ... go through all applications ... */
	a = apps; 
	while (a) {
		/* ... compare this application name with all arguments given
		 * to 'show application' command ... */
		for (app = 2; app < argc; app++) {
			if (!strcasecmp(a->name, argv[app])) {
				/* Maximum number of characters added by terminal coloring is 22 */
				char infotitle[64 + AST_MAX_APP + 22], syntitle[40], destitle[40];
				char info[64 + AST_MAX_APP], *synopsis = NULL, *description = NULL;
				int synopsis_size, description_size;

				no_registered_app = 0;

				if (a->synopsis)
					synopsis_size = strlen(a->synopsis) + 23;
				else
					synopsis_size = strlen("Not available") + 23;
				synopsis = alloca(synopsis_size);

				if (a->description)
					description_size = strlen(a->description) + 23;
				else
					description_size = strlen("Not available") + 23;
				description = alloca(description_size);

				if (synopsis && description) {
					snprintf(info, 64 + AST_MAX_APP, "\n  -= Info about application '%s' =- \n\n", a->name);
					term_color(infotitle, info, COLOR_MAGENTA, 0, 64 + AST_MAX_APP + 22);
					term_color(syntitle, "[Synopsis]:\n", COLOR_MAGENTA, 0, 40);
					term_color(destitle, "[Description]:\n", COLOR_MAGENTA, 0, 40);
					term_color(synopsis,
									a->synopsis ? a->synopsis : "Not available",
									COLOR_CYAN, 0, synopsis_size);