tada.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>


struct s {
	char *str;
};

int
main(int argc, char **argv)
{
	struct s *x;
	size_t len = strlen(argv[0]);

	x = malloc(sizeof(struct s) + len + 1);
	x->str = (char *)(x + 1);
	(void)memcpy(x->str, argv[0], len + 1);
	(void)printf("voila: %s\n", x->str);
	return (0);
}