miscutils/last_fancy.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * (sysvinit like) last implementation
   4  *
   5  * Copyright (C) 2008 by Patricia Muscalu <patricia.muscalu@axis.com>
   6  *
   7  * Licensed under the GPLv2 or later, see the file LICENSE in this tarball.
   8  */
   9
  10 #include "libbb.h"
  11 #include <utmp.h>
  12
  13 /* NB: ut_name and ut_user are the same field, use only one name (ut_user)
  14  * to reduce confusion */
  15
  16 #ifndef SHUTDOWN_TIME
  17 #  define SHUTDOWN_TIME 254
  18 #endif
  19
  20 #define HEADER_FORMAT     "%-8.8s %-12.12s %-*.*s %-16.16s %-7.7s %s\n"
  21 #define HEADER_LINE       "USER", "TTY", \
  22         INET_ADDRSTRLEN, INET_ADDRSTRLEN, "HOST", "LOGIN", "  TIME", ""
  23 #define HEADER_LINE_WIDE  "USER", "TTY", \
  24         INET6_ADDRSTRLEN, INET6_ADDRSTRLEN, "HOST", "LOGIN", "  TIME", ""
  25
  26 enum {
  27         NORMAL,
  28         LOGGED,
  29         DOWN,
  30         REBOOT,
  31         CRASH,
  32         GONE
  33 };
  34
  35 enum {
  36         LAST_OPT_W = (1 << 0),  /* -W wide            */
  37         LAST_OPT_f = (1 << 1),  /* -f input file      */
  38         LAST_OPT_H = (1 << 2),  /* -H header          */
  39 };
  40
  41 #define show_wide (option_mask32 & LAST_OPT_W)
  42
  43 static void show_entry(struct utmp *ut, int state, time_t dur_secs)
  44 {
  45         unsigned days, hours, mins;
  46         char duration[32];
  47         char login_time[17];
  48         char logout_time[8];
  49         const char *logout_str;
  50         const char *duration_str;
  51         time_t tmp;
  52
  53         /* manpages say ut_tv.tv_sec *is* time_t,
  54          * but some systems have it wrong */
  55         tmp = ut->ut_tv.tv_sec;
  56         safe_strncpy(login_time, ctime(&tmp), 17);
  57         snprintf(logout_time, 8, "- %s", ctime(&dur_secs) + 11);
  58
  59         dur_secs = MAX(dur_secs - (time_t)ut->ut_tv.tv_sec, (time_t)0);
  60         /* unsigned int is easier to divide than time_t (which may be signed long) */
  61         mins = dur_secs / 60;
  62         days = mins / (24*60);
  63         mins = mins % (24*60);
  64         hours = mins / 60;
  65         mins = mins % 60;
  66
  67 //      if (days) {
  68                 sprintf(duration, "(%u+%02u:%02u)", days, hours, mins);
  69 //      } else {
  70 //              sprintf(duration, " (%02u:%02u)", hours, mins);
  71 //      }
  72
  73         logout_str = logout_time;
  74         duration_str = duration;
  75         switch (state) {
  76         case NORMAL:
  77                 break;
  78         case LOGGED:
  79                 logout_str = "  still";
  80                 duration_str = "logged in";
  81                 break;
  82         case DOWN:
  83                 logout_str = "- down ";
  84                 break;
  85         case REBOOT:
  86                 break;
  87         case CRASH:
  88                 logout_str = "- crash";
  89                 break;
  90         case GONE:
  91                 logout_str = "   gone";
  92                 duration_str = "- no logout";
  93                 break;
  94         }
  95
  96         printf(HEADER_FORMAT,
  97                    ut->ut_user,
  98                    ut->ut_line,
  99                    show_wide ? INET6_ADDRSTRLEN : INET_ADDRSTRLEN,
 100                    show_wide ? INET6_ADDRSTRLEN : INET_ADDRSTRLEN,
 101                    ut->ut_host,
 102                    login_time,
 103                    logout_str,
 104                    duration_str);
 105 }
 106
 107 static int get_ut_type(struct utmp *ut)
 108 {
 109         if (ut->ut_line[0] == '~') {
 110                 if (strcmp(ut->ut_user, "shutdown") == 0) {
 111                         return SHUTDOWN_TIME;
 112                 }
 113                 if (strcmp(ut->ut_user, "reboot") == 0) {
 114                         return BOOT_TIME;
 115                 }
 116                 if (strcmp(ut->ut_user, "runlevel") == 0) {
 117                         return RUN_LVL;
 118                 }
 119                 return ut->ut_type;
 120         }
 121
 122         if (ut->ut_user[0] == 0) {
 123                 return DEAD_PROCESS;
 124         }
 125
 126         if ((ut->ut_type != DEAD_PROCESS)
 127          && (strcmp(ut->ut_user, "LOGIN") != 0)
 128          && ut->ut_user[0]
 129          && ut->ut_line[0]
 130         ) {
 131                 ut->ut_type = USER_PROCESS;
 132         }
 133
 134         if (strcmp(ut->ut_user, "date") == 0) {
 135                 if (ut->ut_line[0] == '|') {
 136                         return OLD_TIME;
 137                 }
 138                 if (ut->ut_line[0] == '{') {
 139                         return NEW_TIME;
 140                 }
 141         }
 142         return ut->ut_type;
 143 }
 144
 145 static int is_runlevel_shutdown(struct utmp *ut)
 146 {
 147         if (((ut->ut_pid & 255) == '0') || ((ut->ut_pid & 255) == '6')) {
 148                 return 1;
 149         }
 150
 151         return 0;
 152 }
 153
 154 int last_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 155 int last_main(int argc UNUSED_PARAM, char **argv)
 156 {
 157         struct utmp ut;
 158         const char *filename = _PATH_WTMP;
 159         llist_t *zlist;
 160         off_t pos;
 161         time_t start_time;
 162         time_t boot_time;
 163         time_t down_time;
 164         int file;
 165         unsigned opt;
 166         smallint going_down;
 167         smallint boot_down;
 168
 169         opt = getopt32(argv, "Wf:" /* "H" */, &filename);
 170 #ifdef BUT_UTIL_LINUX_LAST_HAS_NO_SUCH_OPT
 171         if (opt & LAST_OPT_H) {
 172                 /* Print header line */
 173                 if (opt & LAST_OPT_W) {
 174                         printf(HEADER_FORMAT, HEADER_LINE_WIDE);
 175                 } else {
 176                         printf(HEADER_FORMAT, HEADER_LINE);
 177                 }
 178         }
 179 #endif
 180
 181         file = xopen(filename, O_RDONLY);
 182         {
 183                 /* in case the file is empty... */
 184                 struct stat st;
 185                 fstat(file, &st);
 186                 start_time = st.st_ctime;
 187         }
 188
 189         time(&down_time);
 190         going_down = 0;
 191         boot_down = NORMAL; /* 0 */
 192         zlist = NULL;
 193         boot_time = 0;
 194         /* get file size, rounding down to last full record */
 195         pos = xlseek(file, 0, SEEK_END) / sizeof(ut) * sizeof(ut);
 196         for (;;) {
 197                 pos -= (off_t)sizeof(ut);
 198                 if (pos < 0) {
 199                         /* Beyond the beginning of the file boundary =>
 200                          * the whole file has been read. */
 201                         break;
 202                 }
 203                 xlseek(file, pos, SEEK_SET);
 204                 xread(file, &ut, sizeof(ut));
 205                 /* rewritten by each record, eventially will have
 206                  * first record's ut_tv.tv_sec: */
 207                 start_time = ut.ut_tv.tv_sec;
 208
 209                 switch (get_ut_type(&ut)) {
 210                 case SHUTDOWN_TIME:
 211                         down_time = ut.ut_tv.tv_sec;
 212                         boot_down = DOWN;
 213                         going_down = 1;
 214                         break;
 215                 case RUN_LVL:
 216                         if (is_runlevel_shutdown(&ut)) {
 217                                 down_time = ut.ut_tv.tv_sec;
 218                                 going_down = 1;
 219                                 boot_down = DOWN;
 220                         }
 221                         break;
 222                 case BOOT_TIME:
 223                         strcpy(ut.ut_line, "system boot");
 224                         show_entry(&ut, REBOOT, down_time);
 225                         boot_down = CRASH;
 226                         going_down = 1;
 227                         break;
 228                 case DEAD_PROCESS:
 229                         if (!ut.ut_line[0]) {
 230                                 break;
 231                         }
 232                         /* add_entry */
 233                         llist_add_to(&zlist, memcpy(xmalloc(sizeof(ut)), &ut, sizeof(ut)));
 234                         break;
 235                 case USER_PROCESS: {
 236                         int show;
 237
 238                         if (!ut.ut_line[0]) {
 239                                 break;
 240                         }
 241                         /* find_entry */
 242                         show = 1;
 243                         {
 244                                 llist_t *el, *next;
 245                                 for (el = zlist; el; el = next) {
 246                                         struct utmp *up = (struct utmp *)el->data;
 247                                         next = el->link;
 248                                         if (strncmp(up->ut_line, ut.ut_line, UT_LINESIZE) == 0) {
 249                                                 if (show) {
 250                                                         show_entry(&ut, NORMAL, up->ut_tv.tv_sec);
 251                                                         show = 0;
 252                                                 }
 253                                                 llist_unlink(&zlist, el);
 254                                                 free(el->data);
 255                                                 free(el);
 256                                         }
 257                                 }
 258                         }
 259
 260                         if (show) {
 261                                 int state = boot_down;
 262
 263                                 if (boot_time == 0) {
 264                                         state = LOGGED;
 265                                         /* Check if the process is alive */
 266                                         if ((ut.ut_pid > 0)
 267                                          && (kill(ut.ut_pid, 0) != 0)
 268                                          && (errno == ESRCH)) {
 269                                                 state = GONE;
 270                                         }
 271                                 }
 272                                 show_entry(&ut, state, boot_time);
 273                         }
 274                         /* add_entry */
 275                         llist_add_to(&zlist, memcpy(xmalloc(sizeof(ut)), &ut, sizeof(ut)));
 276                         break;
 277                 }
 278                 }
 279
 280                 if (going_down) {
 281                         boot_time = ut.ut_tv.tv_sec;
 282                         llist_free(zlist, free);
 283                         zlist = NULL;
 284                         going_down = 0;
 285                 }
 286         }
 287
 288         if (ENABLE_FEATURE_CLEAN_UP) {
 289                 llist_free(zlist, free);
 290         }
 291
 292         printf("\nwtmp begins %s", ctime(&start_time));
 293
 294         if (ENABLE_FEATURE_CLEAN_UP)
 295                 close(file);
 296         fflush_stdout_and_exit(EXIT_SUCCESS);
 297 }