1/* See LICENSE file for copyright and license details. */
 2
 3#include <errno.h>
 4#include <libgen.h>
 5#include <pwd.h>
 6#include <stdio.h>
 7#include <stdlib.h>
 8#include <string.h>
 9#include <time.h>
10#include <unistd.h>
11#include <utmp.h>
12
13#include "config.h"
14#include "paths.h"
15#include "util.h"
16
17static void
18usage(void)
19{
20  eprintf("usage: %s [user]\n", argv0);
21}
22
23// ?man last: show last logged in users
24// ?man arguments: user
25// ?man display a list of recent user logins
26int
27main(int argc, char **argv)
28{
29  FILE       *fp;
30  struct utmp ut;
31  char       *user, *file, *prog;
32  char        ut_name_buf[UT_NAMESIZE + 1];
33  time_t      t;
34
35  ARGBEGIN
36  {
37    default:
38      usage();
39  }
40  ARGEND;
41
42  switch (argc) {
43    case 0:
44      user = NULL;
45      break;
46    case 1:
47      user = argv[0];
48      break;
49    default:
50      usage();
51  }
52
53  prog = basename(argv0);
54  file = (!strcmp(prog, "last")) ? WTMP_PATH : BTMP_PATH;
55  if ((fp = fopen(file, "r")) == NULL)
56    eprintf("fopen %s:", file);
57
58  while (fread(&ut, sizeof(ut), 1, fp) == 1) {
59    memcpy(ut_name_buf, ut.ut_name, UT_NAMESIZE);
60    ut_name_buf[UT_NAMESIZE] = '\0';
61    if (ut.ut_type != USER_PROCESS || (user && strcmp(user, ut_name_buf))) {
62      continue;
63    }
64
65    t = ut.ut_time;
66    printf("%-8.8s %-8.8s %-16.16s %s", ut.ut_user, ut.ut_line, ut.ut_host, ctime(&t));
67  }
68  if (fclose(fp))
69    eprintf("fclose %s:", file);
70  return 0;
71}