Click modular router: example of non element compilation file

hello.click

InfiniteSource(LIMIT 1)
-> UserElem()
-> Discard;

printhello.cc

#include <click/config.h>
#include <click/glue.hh> // for click_chatter()
#include "printhello.hh"

CLICK_DECLS

void print_hello() {
	click_chatter("A word from a non element file : HELLO!\n");
	return 0;
}

CLICK_ENDDECLS
ELEMENT_PROVIDES(PrintHello)

printhello.hh

#ifndef CLICK_PRINTRANDOM_HH
#define CLICK_PRINTRANDOM_HH

#include <click/config.h>

CLICK_DECLS

void print_hello();

CLICK_ENDDECLS

#endif

userelem.cc

#include <click/config.h>
#include "userelem.hh"
#include "printhello.hh"

CLICK_DECLS

UserElem::UserElem() { }
UserElem::~UserElem() { }

Packet* UserElem::simple_action(Packet *p) {
	print_hello();

	return p;
}

CLICK_ENDDECLS
ELEMENT_REQUIRES(PrintHello)
EXPORT_ELEMENT(UserElem)

userelem.hh

#ifndef CLICK_USERELEM_HH
#define CLICK_USERELEM_HH

#include <click/element.hh>

CLICK_DECLS

class UserElem : public Element {
	public:
		UserElem();
		~UserElem();

		const char *class_name() const { return "UserElem"; }
		const char *port_count() const { return PORTS_1_1; }
		const char *processing() const { return AGNOSTIC; }
		int configure(Vector<String>&, ErrorHandler*) { return 0; }

		Packet *simple_action(Packet *);
};

CLICK_ENDDECLS
#endif