New option --full-time.

* src/common.h (full_time_option): New global.
* src/tar.c (FULL_TIME_OPTION): New constant.
(options): New option --full-time.
(parse_opt): Handle the --full-time option.
* src/list.c (simple_print_header): Pass full_time_option
as the 2nd argument to tartime.
* doc/tar.texi: Update.
* NEWS: Update.

src/common.h

@@ -105,6 +105,8 @@ GLOBAL bool absolute_names_option;
 
 /* Display file times in UTC */
 GLOBAL bool utc_option;
+/* Output file timestamps to the full resolution */
+GLOBAL bool full_time_option;
 
 /* This variable tells how to interpret newer_mtime_option, below.  If zero,
    files get archived if their mtime is not less than newer_mtime_option.

src/list.c

@@ -1146,7 +1146,7 @@ simple_print_header (struct tar_stat_info *st, union block *blk,
 
       /* Time stamp.  */
 
-      time_stamp = tartime (st->mtime, false);
+      time_stamp = tartime (st->mtime, full_time_option);
       time_stamp_len = strlen (time_stamp);
       if (datewidth < time_stamp_len)
 	datewidth = time_stamp_len;

src/tar.c

@@ -274,6 +274,7 @@ enum
   EXCLUDE_TAG_ALL_OPTION,
   EXCLUDE_VCS_OPTION,
   FORCE_LOCAL_OPTION,
+  FULL_TIME_OPTION,
   GROUP_OPTION,
   IGNORE_CASE_OPTION,
   IGNORE_COMMAND_ERROR_OPTION,
@@ -752,7 +753,9 @@ static struct argp_option options[] = {
       "Allowed signals are: SIGHUP, SIGQUIT, SIGINT, SIGUSR1 and SIGUSR2; "
       "the names without SIG prefix are also accepted"), GRID+1 },
   {"utc", UTC_OPTION, 0, 0,
-   N_("print file modification dates in UTC"), GRID+1 },
+   N_("print file modification times in UTC"), GRID+1 },
+  {"full-time", FULL_TIME_OPTION, 0, 0,
+   N_("print file time to its full resolution"), GRID+1 },
   {"index-file", INDEX_FILE_OPTION, N_("FILE"), 0,
    N_("send verbose output to FILE"), GRID+1 },
   {"block-number", 'R', 0, 0,
@@ -1437,6 +1440,10 @@ parse_opt (int key, char *arg, struct argp_state *state)
       info_script_option = arg;
       multi_volume_option = true;
       break;
+
+    case FULL_TIME_OPTION:
+      full_time_option = true;
+      break;
       
     case 'g':
       listed_incremental_option = arg;