Unix C

#include
#include
#include
#include
int main()
{
gid_t gid;
if ((gid = getgid()) < 0) {
perror("
getgid error");
} else {
printf("
The group id is : %d", gid);
}
if ((gid = getegid()) < 0) {
perror("
getegid error");
} else {
printf("
The effective group id is : %d", gid);
}
printf("
");
return(0);
}