A little example showing how ptrace works under OSX

ptrace-exmaple.c

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/ptrace.h>
#include <unistd.h>

int main(int argc, char *argv[])
{
	int target_pid;
	long ret;
	
	target_pid = atoi(argv[1]);
	printf("attach to %i \n", target_pid);
	
	ret = ptrace (PT_ATTACH, target_pid, NULL, 0);
	printf("attach %lu \n", ret);
	
	sleep(5);
	
	ret = ptrace (PT_CONTINUE, target_pid, NULL, 0);
	printf("continue %lu \n", ret);

	sleep(5);
	
	ret = ptrace (PT_DETACH, target_pid, NULL, 0);
	printf("detach %lu \n", ret);
}