constructor1.c

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

void anti_trace(void) __attribute__ ((constructor));
void anti_trace(void)
{
    printf("checking for signs of alien life...\n");
    if(ptrace(PTRACE_TRACEME, 0, 0, 0) < 0)
    {
        printf("Aliens found!\n");
        exit(0);
    }
}

void message()
{
    printf("Execution success!\n");
}

int main()
{
    message();
    return 0;
}