simplest cgo program

Have been struggling to make a simple cgo sample to get familiar on how to link c code and go library.

Finally made it working.

cgo_test.go

-------------------------------

package cgo_test

/*

#include

void out() {

printf("Hello world from c\n");

}

*/

import "C"

func Out() {

C.out()

}

--------------------------------------------------------

main.go

--------------------------------------------------------

package main

import "cgo_test"

func main() {

cgo_test.Out()

}

--------------------------------------------------------

Makefile

--------------------------------------------------------

include ../go/src/Make.inc

TARG=cgo_test

CGOFILES=cgo_test.go

CLEANFILES+=main

include ../go/src/Make.pkg

main: install main.go

$(GC) main.go

$(LD) -o $@ main.$O

The most annoy error message I got is something like:

gomake main

main.go:6: cannot refer to unexported name cgo_test.out

main.go:6: undefined: cgo_test.out

It seems that GO only export Initcap names by default.