cgo-argc-argv.go

/*
An example that converts os.Args to argc/argv for C.
Can be used with any []string with the same procedure.
*/

package main

/*
#include <stdio.h>
#include <stdlib.h>

void print_argv(int argc, char** argv) {
  for (int i = 0; i < argc; i++)
    printf("%d: %s\n", i, argv[i]);
}
*/
import "C"
import (
	"os"
	"runtime"
	"unsafe"
)

func main() {
	runtime.LockOSThread()
	defer runtime.UnlockOSThread()

	args := make([]*C.char, len(os.Args))
	for i, arg := range os.Args {
		args[i] = C.CString(arg)
		defer C.free(unsafe.Pointer(args[i]))
	}
	argc := C.int(len(args))
	argv := (**C.char)(unsafe.Pointer(&args[0]))

	C.print_argv(argc, argv)
}