1. 
command xsh_yourFunction(...){

	GPIO_CTRL_LED_ON(ledID);
	
	// delay some time.
	for(...){
	}

	GPIO_CTRL_LED_ON(ledID);

	// several on-off pairs to make leds blinking.
	
}

2. 
// implement a delay function

int delaySomeTime(int delay){
	
	// for loop or any other methods for delay
	for( ... ){

	}

	return 1;
}

// using the delay function in the xsh_yourFunction() function.

command xsh_yourFunction(...){

	GPIO_CTRL_LED_ON(ledID);
	delaySomeTime(100000);	
	GPIO_CTRL_LED_ON(ledID);

	// several on-off pairs to make leds blinking.
	
}

3. 
// implement a function for a specific led on/off for some time
int turnOnOffALed(int ledID, int delay){
	GPIO_CTRL_LED_ON(ledID);
	delaySomeTime(delay);	
	GPIO_CTRL_LED_ON(ledID);	
}

// Then your final command will be 

command xsh_yourFunction(...){

	turnOnOffALed(led, 100000);

	turnOnOffALed(...);


}