C Programming Code Examples C > C on Unix Code Examples Program to get the GroupID ( GID ) information Program to get the GroupID ( GID ) information #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/types.h> 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); }