setuidtest.c

#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
int main(void)
{
    printf("My UID is: %d. My GID is: %d My EUID is: %d. My EGID is: %d \n", getuid(), getgid() , geteuid(), getegid());
    system("/usr/bin/id");
    setuid(geteuid());
    printf("My UID is: %d. My GID is: %d My EUID is: %d. My EGID is: %d \n", getuid(), getgid() , geteuid(), getegid());
    system("/usr/bin/id");
    return 0;
}