Changeset 2725 in MondoRescue for branches/2.2.9/mindi-busybox/miscutils/last.c

Timestamp:

Feb 25, 2011, 9:26:54 PM (13 years ago)

Author:

Bruno Cornec

Message:

• Update mindi-busybox to 1.18.3 to avoid problems with the tar command which is now failing on recent versions with busybox 1.7.3

File:

• branches/2.2.9/mindi-busybox/miscutils/last.c (modified) (4 diffs)

branches/2.2.9/mindi-busybox/miscutils/last.c

@@ -5 +5 @@
  * Copyright (C) 2003-2004 by Erik Andersen <andersen@codepoet.org>
  *
- * Licensed under the GPL version 2, see the file LICENSE in this tarball.
+ * Licensed under GPLv2, see file LICENSE in this source tree.
  */
 
@@ -11 +11 @@
 #include <utmp.h>
 
+/* NB: ut_name and ut_user are the same field, use only one name (ut_user)
+ * to reduce confusion */
+
 #ifndef SHUTDOWN_TIME
 #  define SHUTDOWN_TIME 254
 #endif
 
-/* Grr... utmp char[] members  do not have to be nul-terminated.
+/* Grr... utmp char[] members do not have to be nul-terminated.
  * Do what we can while still keeping this reasonably small.
  * Note: We are assuming the ut_id[] size is fixed at 4. */
@@ -27 +30 @@
 #endif
 
-int last_main(int argc, char **argv);
-int last_main(int argc, char **argv)
+#if EMPTY != 0 || RUN_LVL != 1 || BOOT_TIME != 2 || NEW_TIME != 3 || \
+    OLD_TIME != 4
+#error Values for the ut_type field of struct utmp changed
+#endif
+
+int last_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int last_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 {
     struct utmp ut;
     int n, file = STDIN_FILENO;
     time_t t_tmp;
+    off_t pos;
+    static const char _ut_usr[] ALIGN1 =
+            "runlevel\0" "reboot\0" "shutdown\0";
+    static const char _ut_lin[] ALIGN1 =
+            "~\0" "{\0" "|\0" /* "LOGIN\0" "date\0" */;
+    enum {
+        TYPE_RUN_LVL = RUN_LVL,         /* 1 */
+        TYPE_BOOT_TIME = BOOT_TIME,     /* 2 */
+        TYPE_SHUTDOWN_TIME = SHUTDOWN_TIME
+    };
+    enum {
+        _TILDE = EMPTY, /* 0 */
+        TYPE_NEW_TIME,  /* NEW_TIME, 3 */
+        TYPE_OLD_TIME   /* OLD_TIME, 4 */
+    };
 
-    if (argc > 1) {
+    if (argv[1]) {
         bb_show_usage();
     }
     file = xopen(bb_path_wtmp_file, O_RDONLY);
 
-    printf("%-10s %-14s %-18s %-12.12s %s\n", "USER", "TTY", "HOST", "LOGIN", "TIME");
-    while ((n = safe_read(file, (void*)&ut, sizeof(struct utmp))) != 0) {
-
-        if (n != sizeof(struct utmp)) {
+    printf("%-10s %-14s %-18s %-12.12s %s\n",
+           "USER", "TTY", "HOST", "LOGIN", "TIME");
+    /* yikes. We reverse over the file and that is a not too elegant way */
+    pos = xlseek(file, 0, SEEK_END);
+    pos = lseek(file, pos - sizeof(ut), SEEK_SET);
+    while ((n = full_read(file, &ut, sizeof(ut))) > 0) {
+        if (n != sizeof(ut)) {
             bb_perror_msg_and_die("short read");
         }
-
-        if (ut.ut_line[0] == '~') {
+        n = index_in_strings(_ut_lin, ut.ut_line);
+        if (n == _TILDE) { /* '~' */
+#if 1
+/* do we really need to be cautious here? */
+            n = index_in_strings(_ut_usr, ut.ut_user);
+            if (++n > 0)
+                ut.ut_type = n != 3 ? n : SHUTDOWN_TIME;
+#else
             if (strncmp(ut.ut_user, "shutdown", 8) == 0)
                 ut.ut_type = SHUTDOWN_TIME;
             else if (strncmp(ut.ut_user, "reboot", 6) == 0)
                 ut.ut_type = BOOT_TIME;
-            else if (strncmp(ut.ut_user, "runlevel", 7) == 0)
+            else if (strncmp(ut.ut_user, "runlevel", 8) == 0)
                 ut.ut_type = RUN_LVL;
+#endif
         } else {
-            if (!ut.ut_name[0] || strcmp(ut.ut_name, "LOGIN") == 0 ||
-                    ut.ut_name[0] == 0)
-            {
+            if (ut.ut_user[0] == '\0' || strcmp(ut.ut_user, "LOGIN") == 0) {
                 /* Don't bother.  This means we can't find how long
                  * someone was logged in for.  Oh well. */
-                continue;
+                goto next;
             }
-            if (ut.ut_type != DEAD_PROCESS &&
-                    ut.ut_name[0] && ut.ut_line[0])
-            {
+            if (ut.ut_type != DEAD_PROCESS
+             && ut.ut_user[0]
+             && ut.ut_line[0]
+            ) {
                 ut.ut_type = USER_PROCESS;
             }
-            if (strcmp(ut.ut_name, "date") == 0) {
-                if (ut.ut_line[0] == '|') ut.ut_type = OLD_TIME;
-                if (ut.ut_line[0] == '{') ut.ut_type = NEW_TIME;
+            if (strcmp(ut.ut_user, "date") == 0) {
+                if (n == TYPE_OLD_TIME) { /* '|' */
+                    ut.ut_type = OLD_TIME;
+                }
+                if (n == TYPE_NEW_TIME) { /* '{' */
+                    ut.ut_type = NEW_TIME;
+                }
             }
         }
 
-        if (ut.ut_type!=USER_PROCESS) {
+        if (ut.ut_type != USER_PROCESS) {
             switch (ut.ut_type) {
                 case OLD_TIME:
@@ -78 +114 @@
                 case RUN_LVL:
                 case SHUTDOWN_TIME:
-                    continue;
+                    goto next;
                 case BOOT_TIME:
                     strcpy(ut.ut_line, "system boot");
-                    break;
             }
         }
+        /* manpages say ut_tv.tv_sec *is* time_t,
+         * but some systems have it wrong */
         t_tmp = (time_t)ut.ut_tv.tv_sec;
-        printf("%-10s %-14s %-18s %-12.12s\n", ut.ut_user, ut.ut_line, ut.ut_host,
-                ctime(&t_tmp) + 4);
+        printf("%-10s %-14s %-18s %-12.12s\n",
+               ut.ut_user, ut.ut_line, ut.ut_host, ctime(&t_tmp) + 4);
+ next:
+        pos -= sizeof(ut);
+        if (pos <= 0)
+            break; /* done. */
+        xlseek(file, pos, SEEK_SET);
     }