/* ip2.c   by Michael Thorpe   2000-08-07 */

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

int main(int argc,char **argv) {
   int i,v=0;
   uid_t u;
   gid_t g,*a;
   struct passwd *pw;
   struct group *gr;

   if(argc==2 && argv[1][0]=='-' && argv[1][1]=='v' && !argv[1][2])
      v=1;
   else if(argc != 1)
      return(0<printf("usage: %s [-v]\n",argv[0]));
   u=getuid();
   printf("ruid=%d",u);
   if(v && (pw=getpwuid(u)))
      printf("(%s)",pw->pw_name);
   u=geteuid();
   printf(" euid=%d",u);
   if(v && (pw=getpwuid(u)))
      printf("(%s)",pw->pw_name);
   g=getgid();
   printf(" rgid=%d",g);
   if(v && (gr=getgrgid(g)))
      printf("(%s)",gr->gr_name);
   g=getegid();
   printf(" egid=%d",g);
   if(v && (gr=getgrgid(g)))
      printf("(%s)",gr->gr_name);
   i=getgroups(0,0);
   if(i>0) {
      a=(gid_t *)malloc(i*sizeof(gid_t));
      if(!a)
         exit(-1);
      getgroups(i,a);
      printf(" groups=%d",a[--i]);
      if(v && (gr=getgrgid(a[i])))
         printf("(%s)",gr->gr_name);
      while(i) {
         printf(",%d",a[--i]);
         if(v && (gr=getgrgid(a[i])))
            printf("(%s)",gr->gr_name);
      }
      free(a);
   }
   return(1==printf("\n"));
}