else if(strstr(buff, "undo") != NULL)
{
	char aux[8], val[32];

	sscanf(buff, "%s %s", aux, val);

	if (!strcmp(aux, "copy"))
	{

	}
	else if (!strcmp(aux, "move"))
	{
		move(&head, -atoi(aux));
	}
	...
	printf("UNdo");
}