ps: conditionally enable -T on non-DESKTOP build too
[oweals/busybox.git] / miscutils / last.c
index f254118816291bc8ab55ee29d3bbd14598fb6026..f8c301395de14cd961fc22ce330a71f06697e0eb 100644 (file)
@@ -10,6 +10,9 @@
 #include "libbb.h"
 #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
@@ -32,7 +35,7 @@
 #endif
 
 int last_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int last_main(int argc, char **argv ATTRIBUTE_UNUSED)
+int last_main(int argc, char **argv UNUSED_PARAM)
 {
        struct utmp ut;
        int n, file = STDIN_FILENO;
@@ -83,17 +86,17 @@ int last_main(int argc, char **argv ATTRIBUTE_UNUSED)
                                ut.ut_type = RUN_LVL;
 #endif
                } else {
-                       if (ut.ut_name[0] == '\0' || strcmp(ut.ut_name, "LOGIN") == 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. */
                                goto next;
                        }
                        if (ut.ut_type != DEAD_PROCESS
-                        && ut.ut_name[0] && ut.ut_line[0]
+                        && ut.ut_user[0] && ut.ut_line[0]
                        ) {
                                ut.ut_type = USER_PROCESS;
                        }
-                       if (strcmp(ut.ut_name, "date") == 0) {
+                       if (strcmp(ut.ut_user, "date") == 0) {
                                if (n == TYPE_OLD_TIME) { /* '|' */
                                        ut.ut_type = OLD_TIME;
                                }
@@ -114,13 +117,16 @@ int last_main(int argc, char **argv ATTRIBUTE_UNUSED)
                                        strcpy(ut.ut_line, "system boot");
                        }
                }
+               /* 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);
  next:
-               if (!pos)
+               pos -= sizeof(ut);
+               if (pos <= 0)
                        break; /* done. */
-               pos = lseek(file, pos - sizeof(ut), SEEK_SET);
+               xlseek(file, pos, SEEK_SET);
        }
 
        fflush_stdout_and_exit(EXIT_SUCCESS);