--- a/src/ChangeLog	Mon Apr 25 16:36:32 2005 +0000
+++ b/src/ChangeLog	Tue Apr 26 02:59:08 2005 +0000
@@ -1,3 +1,18 @@
+2005-04-25  John W. Eaton  <jwe@octave.org>
+
+	* oct-hist.cc (default_history_file, default_history_size): Now static.
+	* oct-hist.h: Delete decls.
+
+	* oct-hist.cc (default_history_timestamp_format,
+	default_history_timestamp_format): New functions.
+	(Vdefault_history_timestamp_format): New variable.
+	(symbols_of_oct_hist): DEFVAR it.
+	(octave_history_write_timestamp): New function.
+	* oct-hist.h (octave_history_write_timestamp): Provide decl.
+	* toplev.cc (): call octave_history_write_timestamp here.
+	* octave.cc (maximum_braindamage):
+	Bind history_timestamp_format_string here.
+
 2005-04-22  John W. Eaton  <jwe@octave.org>
 
 	* version.h (OCTAVE_VERSION): Now 2.9.2.

--- a/src/oct-hist.cc	Mon Apr 25 16:36:32 2005 +0000
+++ b/src/oct-hist.cc	Tue Apr 26 02:59:08 2005 +0000
@@ -53,6 +53,7 @@
 #include "file-ops.h"
 #include "lo-mappers.h"
 #include "oct-env.h"
+#include "oct-time.h"
 #include "str-vec.h"
 
 #include <defaults.h>
@@ -80,31 +81,17 @@
 // The number of lines to keep in the history file.
 static int Vhistory_size;
 
+// The format of the timestamp marker written to the history file when
+// Octave exits.
+static std::string Vhistory_timestamp_format_string;
+
 // TRUE if we are saving history.
 bool Vsaving_history = true;
 
 // Get some default values, possibly reading them from the
 // environment.
 
-int
-default_history_size (void)
-{
-  int size = 1024;
-
-  std::string env_size = octave_env::getenv ("OCTAVE_HISTSIZE");
-
-  if (! env_size.empty ())
-    {
-      int val;
-
-      if (sscanf (env_size.c_str (), "%d", &val) == 1)
-	size = val > 0 ? val : 0;
-    }
-
-  return size;
-}
-
-std::string
+static std::string
 default_history_file (void)
 {
   std::string file;
@@ -138,6 +125,35 @@
   return file;
 }
 
+static int
+default_history_size (void)
+{
+  int size = 1024;
+
+  std::string env_size = octave_env::getenv ("OCTAVE_HISTSIZE");
+
+  if (! env_size.empty ())
+    {
+      int val;
+
+      if (sscanf (env_size.c_str (), "%d", &val) == 1)
+	size = val > 0 ? val : 0;
+    }
+
+  return size;
+}
+
+static std::string
+default_history_timestamp_format (void)
+{
+  return
+    std::string ("# Octave " OCTAVE_VERSION ", %a %b %d %H:%M:%S %Y %Z <")
+    + octave_env::get_user_name ()
+    + std::string ("@")
+    + octave_env::get_host_name ()
+    + std::string (">");
+}
+
 // Display, save, or load history.  Stolen and modified from bash.
 //
 // Arg of -w FILENAME means write file, arg of -r FILENAME
@@ -533,6 +549,17 @@
   unlink (name.c_str ());
 }
 
+void
+octave_history_write_timestamp (void)
+{
+  octave_localtime now;
+
+  std::string timestamp = now.strftime (Vhistory_timestamp_format_string);
+
+  if (! timestamp.empty ())
+    command_history::add (timestamp);
+}
+
 DEFCMD (edit_history, args, ,
   "-*- texinfo -*-\n\
 @deffn {Command} edit_history options\n\
@@ -688,6 +715,24 @@
 }
 
 static int
+history_timestamp_format_string (void)
+{
+  int status = 0;
+
+  octave_value v = builtin_any_variable ("history_timestamp_format_string");
+
+  if (v.is_string ())
+    Vhistory_timestamp_format_string = v.string_value ();
+  else
+    {
+      gripe_invalid_value_specified ("history_timestamp_format_string");
+      status = -1;
+    }
+
+  return status;
+}
+
+static int
 saving_history (void)
 {
   Vsaving_history = check_preference ("saving_history");
@@ -718,6 +763,21 @@
 environment variable @code{OCTAVE_HISTSIZE}.\n\
 @end defvr");
 
+  DEFVAR (history_timestamp_format_string,
+	  default_history_timestamp_format (),
+	  history_timestamp_format_string,
+    "-*- texinfo -*-\n\
+@defvr {Built-in Variable} history_timestamp_format_string\n\
+This variable specifies the the format string for the comment line\n\
+that is written to the history file when Octave exits.  The format\n\
+string is passed to @code{strftime}.  The default value is\n\
+\n\
+@example\n\
+\"# Octave VERSION, %a %b %d %H:%M:%S %Y %Z <USER@@HOST>\"\n\
+@end example\n\
+@seealso{strftime}\n\
+@end defvr");
+
   DEFVAR (saving_history, true, saving_history,
     "-*- texinfo -*-\n\
 @defvr {Built-in Variable} saving_history\n\

--- a/src/oct-hist.h	Mon Apr 25 16:36:32 2005 +0000
+++ b/src/oct-hist.h	Tue Apr 26 02:59:08 2005 +0000
@@ -27,8 +27,8 @@
 
 #include "cmd-hist.h"
 
-extern int default_history_size (void);
-extern std::string default_history_file (void);
+// Write timestamp to history file.
+extern void octave_history_write_timestamp (void);
 
 // TRUE means input is coming from temporary history file.
 extern bool input_from_tmp_history_file;

--- a/src/octave.cc	Mon Apr 25 16:36:32 2005 +0000
+++ b/src/octave.cc	Tue Apr 26 02:59:08 2005 +0000
@@ -433,6 +433,8 @@
   bind_builtin_variable ("crash_dumps_octave_core", false);
   bind_builtin_variable ("default_save_options", "-mat-binary");
   bind_builtin_variable ("fixed_point_format", true);
+  bind_builtin_variable ("history_timestamp_format_string",
+			 "%%-- %D %I:%M %p --%%");
   bind_builtin_variable ("page_screen_output", false);
   bind_builtin_variable ("print_empty_dimensions", false);
   bind_builtin_variable ("warn_function_name_clash", false);

--- a/src/toplev.cc	Mon Apr 25 16:36:32 2005 +0000
+++ b/src/toplev.cc	Tue Apr 26 02:59:08 2005 +0000
@@ -545,6 +545,8 @@
       // XXX FIXME XXX -- is this needed?  Can it cause any trouble?
       raw_mode (0);
 
+      octave_history_write_timestamp ();
+
       command_history::clean_up_and_save ();
 
       close_files ();
@@ -553,7 +555,7 @@
 
       flush_octave_stdout ();
 
-      if (!quitting_gracefully && (interactive || forced_interactive))
+      if (! quitting_gracefully && (interactive || forced_interactive))
 	std::cout << "\n";
     }
 }