The following patch adds a "SHOW LAST_BINLOG_EVENT" command to MySQL, to show you the
binlog filename and event position of the last event that went into the binlog for
the current thread.  For example:

mysql> show last_binlog_event;
+---------------------------------+----------+
| Binlog                          | Position |
+---------------------------------+----------+
| /var/log/mysql/mysql-bin.000002 |       79 |
+---------------------------------+----------+
1 row in set (0.00 sec)

On initial thread creation, values are NULL:

mysql> show last_binlog_event;
+--------+----------+
| Binlog | Position |
+--------+----------+
| NULL   |     NULL |
+--------+----------+
1 row in set (0.00 sec)

                                  -- Brad Fitzpatrick
                                     brad@danga.com
                                     July 20, 2004


diff -ur -x '*sql_yacc.cc' -x '*fill_help*' -x '*mysqlbug*' -x '*sql_yacc.h' mysql-4.1.3-beta/libmysqld/log.cc mysql-4.1.3-lastbinlog/libmysqld/log.cc
--- mysql-4.1.3-beta/libmysqld/log.cc	2004-06-27 14:56:51.000000000 -0700
+++ mysql-4.1.3-lastbinlog/libmysqld/log.cc	2004-07-20 13:20:22.000000000 -0700
@@ -1372,6 +1372,15 @@
     if (event_info->write(file))
       goto err;
 
+    /* keep track of this thread's last binlog event's file and position */
+    if (thd)
+    {
+      thd->last_binlog_pos = event_info->log_pos;
+      memcpy(&thd->last_binlog_name,
+             log_file_name,
+             FN_REFLEN);
+    }
+
     /* Write log events to reset the 'run environment' of the SQL command */
 
     if (thd && thd->options & OPTION_NO_FOREIGN_KEY_CHECKS)
diff -ur -x '*sql_yacc.cc' -x '*fill_help*' -x '*mysqlbug*' -x '*sql_yacc.h' mysql-4.1.3-beta/libmysqld/sql_class.cc mysql-4.1.3-lastbinlog/libmysqld/sql_class.cc
--- mysql-4.1.3-beta/libmysqld/sql_class.cc	2004-06-27 14:56:50.000000000 -0700
+++ mysql-4.1.3-lastbinlog/libmysqld/sql_class.cc	2004-07-20 14:56:26.000000000 -0700
@@ -288,6 +288,8 @@
   warn_list.empty();
   bzero((char*) warn_count, sizeof(warn_count));
   total_warn_count= 0;
+  last_binlog_name[0] = '\0';
+  last_binlog_pos = 0;
   update_charset();
 }
 
diff -ur -x '*sql_yacc.cc' -x '*fill_help*' -x '*mysqlbug*' -x '*sql_yacc.h' mysql-4.1.3-beta/libmysqld/sql_parse.cc mysql-4.1.3-lastbinlog/libmysqld/sql_parse.cc
--- mysql-4.1.3-beta/libmysqld/sql_parse.cc	2004-06-27 14:56:49.000000000 -0700
+++ mysql-4.1.3-lastbinlog/libmysqld/sql_parse.cc	2004-07-20 13:52:57.000000000 -0700
@@ -2950,6 +2950,9 @@
   case SQLCOM_SHOW_OPEN_TABLES:
     res= mysqld_show_open_tables(thd,(lex->wild ? lex->wild->ptr() : NullS));
     break;
+  case SQLCOM_SHOW_LAST_BINLOG_EVENT:
+    res= mysqld_show_last_binlog_event(thd);
+    break;
   case SQLCOM_SHOW_CHARSETS:
     res= mysqld_show_charsets(thd,(lex->wild ? lex->wild->ptr() : NullS));
     break;
diff -ur -x '*sql_yacc.cc' -x '*fill_help*' -x '*mysqlbug*' -x '*sql_yacc.h' mysql-4.1.3-beta/libmysqld/sql_show.cc mysql-4.1.3-lastbinlog/libmysqld/sql_show.cc
--- mysql-4.1.3-beta/libmysqld/sql_show.cc	2004-06-27 14:56:51.000000000 -0700
+++ mysql-4.1.3-lastbinlog/libmysqld/sql_show.cc	2004-07-20 14:57:00.000000000 -0700
@@ -130,6 +130,39 @@
   DBUG_RETURN(0);
 }
 
+/***************************************************************************
+  List the last binlog event
+***************************************************************************/
+
+int mysqld_show_last_binlog_event(THD *thd)
+{
+  List<Item> field_list;
+  Protocol *protocol= thd->protocol;
+  DBUG_ENTER("mysqld_show_last_binlog_event");
+
+  field_list.push_back(new Item_empty_string("Binlog", NAME_LEN));
+  field_list.push_back(new Item_return_int("Position", 1, MYSQL_TYPE_LONG));
+
+  if (protocol->send_fields(&field_list,1))
+    DBUG_RETURN(1);
+
+  protocol->prepare_for_resend();
+  if (thd->last_binlog_name[0]) {
+    protocol->store(&thd->last_binlog_name[0], system_charset_info);
+    protocol->store_long((longlong) thd->last_binlog_pos);
+  } else {
+    protocol->store_null();
+    protocol->store_null();
+  }
+  if (protocol->write())
+  {
+    DBUG_RETURN(-1);
+  }
+
+  send_eof(thd);
+  DBUG_RETURN(0);
+}
+
 
 /***************************************************************************
 ** List all tables in a database (fast version)
diff -ur -x '*sql_yacc.cc' -x '*fill_help*' -x '*mysqlbug*' -x '*sql_yacc.h' mysql-4.1.3-beta/sql/lex.h mysql-4.1.3-lastbinlog/sql/lex.h
--- mysql-4.1.3-beta/sql/lex.h	2004-06-27 14:56:50.000000000 -0700
+++ mysql-4.1.3-lastbinlog/sql/lex.h	2004-07-20 13:35:16.000000000 -0700
@@ -237,6 +237,7 @@
   { "KEYS",		SYM(KEYS)},
   { "KILL",		SYM(KILL_SYM)},
   { "LAST",		SYM(LAST_SYM)},
+  { "LAST_BINLOG_EVENT",SYM(LAST_BINLOG_EVENT_SYM)},
   { "LEADING",		SYM(LEADING)},
   { "LEAVES",		SYM(LEAVES)},
   { "LEFT",		SYM(LEFT)},
diff -ur -x '*sql_yacc.cc' -x '*fill_help*' -x '*mysqlbug*' -x '*sql_yacc.h' mysql-4.1.3-beta/sql/log.cc mysql-4.1.3-lastbinlog/sql/log.cc
--- mysql-4.1.3-beta/sql/log.cc	2004-06-27 14:56:51.000000000 -0700
+++ mysql-4.1.3-lastbinlog/sql/log.cc	2004-07-20 13:20:22.000000000 -0700
@@ -1372,6 +1372,15 @@
     if (event_info->write(file))
       goto err;
 
+    /* keep track of this thread's last binlog event's file and position */
+    if (thd)
+    {
+      thd->last_binlog_pos = event_info->log_pos;
+      memcpy(&thd->last_binlog_name,
+             log_file_name,
+             FN_REFLEN);
+    }
+
     /* Write log events to reset the 'run environment' of the SQL command */
 
     if (thd && thd->options & OPTION_NO_FOREIGN_KEY_CHECKS)
diff -ur -x '*sql_yacc.cc' -x '*fill_help*' -x '*mysqlbug*' -x '*sql_yacc.h' mysql-4.1.3-beta/sql/mysql_priv.h mysql-4.1.3-lastbinlog/sql/mysql_priv.h
--- mysql-4.1.3-beta/sql/mysql_priv.h	2004-06-27 14:56:51.000000000 -0700
+++ mysql-4.1.3-lastbinlog/sql/mysql_priv.h	2004-07-20 13:53:58.000000000 -0700
@@ -616,6 +616,7 @@
 /* sql_show.cc */
 int mysqld_show_dbs(THD *thd,const char *wild);
 int mysqld_show_open_tables(THD *thd,const char *wild);
+int mysqld_show_last_binlog_event(THD *thd);
 int mysqld_show_tables(THD *thd,const char *db,const char *wild);
 int mysqld_extend_show_tables(THD *thd,const char *db,const char *wild);
 int mysqld_show_fields(THD *thd,TABLE_LIST *table, const char *wild,
diff -ur -x '*sql_yacc.cc' -x '*fill_help*' -x '*mysqlbug*' -x '*sql_yacc.h' mysql-4.1.3-beta/sql/mysqld.cc mysql-4.1.3-lastbinlog/sql/mysqld.cc
--- mysql-4.1.3-beta/sql/mysqld.cc	2004-06-27 14:56:49.000000000 -0700
+++ mysql-4.1.3-lastbinlog/sql/mysqld.cc	2004-07-20 13:52:39.000000000 -0700
@@ -5174,6 +5174,7 @@
   {"Select_range",             (char*) &select_range_count, 	SHOW_LONG},
   {"Select_range_check",       (char*) &select_range_check_count, SHOW_LONG},
   {"Select_scan",	       (char*) &select_scan_count,	SHOW_LONG},
+  {"Show_last_binlog_event",   (char*) (com_stat+(uint) SQLCOM_SHOW_LAST_BINLOG_EVENT),SHOW_LONG},
   {"Slave_open_temp_tables",   (char*) &slave_open_temp_tables, SHOW_LONG},
   {"Slave_running",            (char*) 0, SHOW_SLAVE_RUNNING},
   {"Slow_launch_threads",      (char*) &slow_launch_threads,    SHOW_LONG},
diff -ur -x '*sql_yacc.cc' -x '*fill_help*' -x '*mysqlbug*' -x '*sql_yacc.h' mysql-4.1.3-beta/sql/sql_class.cc mysql-4.1.3-lastbinlog/sql/sql_class.cc
--- mysql-4.1.3-beta/sql/sql_class.cc	2004-06-27 14:56:50.000000000 -0700
+++ mysql-4.1.3-lastbinlog/sql/sql_class.cc	2004-07-20 14:56:26.000000000 -0700
@@ -288,6 +288,8 @@
   warn_list.empty();
   bzero((char*) warn_count, sizeof(warn_count));
   total_warn_count= 0;
+  last_binlog_name[0] = '\0';
+  last_binlog_pos = 0;
   update_charset();
 }
 
diff -ur -x '*sql_yacc.cc' -x '*fill_help*' -x '*mysqlbug*' -x '*sql_yacc.h' mysql-4.1.3-beta/sql/sql_class.h mysql-4.1.3-lastbinlog/sql/sql_class.h
--- mysql-4.1.3-beta/sql/sql_class.h	2004-06-27 14:57:00.000000000 -0700
+++ mysql-4.1.3-lastbinlog/sql/sql_class.h	2004-07-20 13:10:22.000000000 -0700
@@ -852,6 +852,10 @@
     long    long_value;
   } sys_var_tmp;
 
+  /* keep track of this thread's last binlog event's file and position */
+  char last_binlog_name[FN_REFLEN];
+  my_off_t last_binlog_pos;
+
   THD();
   ~THD();
 
diff -ur -x '*sql_yacc.cc' -x '*fill_help*' -x '*mysqlbug*' -x '*sql_yacc.h' mysql-4.1.3-beta/sql/sql_lex.h mysql-4.1.3-lastbinlog/sql/sql_lex.h
--- mysql-4.1.3-beta/sql/sql_lex.h	2004-06-27 14:56:48.000000000 -0700
+++ mysql-4.1.3-lastbinlog/sql/sql_lex.h	2004-07-20 13:50:35.000000000 -0700
@@ -77,6 +77,7 @@
   SQLCOM_HELP, SQLCOM_DROP_USER, SQLCOM_REVOKE_ALL, SQLCOM_CHECKSUM,
 
   SQLCOM_PREPARE, SQLCOM_EXECUTE, SQLCOM_DEALLOCATE_PREPARE,
+  SQLCOM_SHOW_LAST_BINLOG_EVENT,
   /* This should be the last !!! */
   SQLCOM_END
 };
diff -ur -x '*sql_yacc.cc' -x '*fill_help*' -x '*mysqlbug*' -x '*sql_yacc.h' mysql-4.1.3-beta/sql/sql_parse.cc mysql-4.1.3-lastbinlog/sql/sql_parse.cc
--- mysql-4.1.3-beta/sql/sql_parse.cc	2004-06-27 14:56:49.000000000 -0700
+++ mysql-4.1.3-lastbinlog/sql/sql_parse.cc	2004-07-20 13:52:57.000000000 -0700
@@ -2950,6 +2950,9 @@
   case SQLCOM_SHOW_OPEN_TABLES:
     res= mysqld_show_open_tables(thd,(lex->wild ? lex->wild->ptr() : NullS));
     break;
+  case SQLCOM_SHOW_LAST_BINLOG_EVENT:
+    res= mysqld_show_last_binlog_event(thd);
+    break;
   case SQLCOM_SHOW_CHARSETS:
     res= mysqld_show_charsets(thd,(lex->wild ? lex->wild->ptr() : NullS));
     break;
diff -ur -x '*sql_yacc.cc' -x '*fill_help*' -x '*mysqlbug*' -x '*sql_yacc.h' mysql-4.1.3-beta/sql/sql_show.cc mysql-4.1.3-lastbinlog/sql/sql_show.cc
--- mysql-4.1.3-beta/sql/sql_show.cc	2004-06-27 14:56:51.000000000 -0700
+++ mysql-4.1.3-lastbinlog/sql/sql_show.cc	2004-07-20 14:57:00.000000000 -0700
@@ -130,6 +130,39 @@
   DBUG_RETURN(0);
 }
 
+/***************************************************************************
+  List the last binlog event
+***************************************************************************/
+
+int mysqld_show_last_binlog_event(THD *thd)
+{
+  List<Item> field_list;
+  Protocol *protocol= thd->protocol;
+  DBUG_ENTER("mysqld_show_last_binlog_event");
+
+  field_list.push_back(new Item_empty_string("Binlog", NAME_LEN));
+  field_list.push_back(new Item_return_int("Position", 1, MYSQL_TYPE_LONG));
+
+  if (protocol->send_fields(&field_list,1))
+    DBUG_RETURN(1);
+
+  protocol->prepare_for_resend();
+  if (thd->last_binlog_name[0]) {
+    protocol->store(&thd->last_binlog_name[0], system_charset_info);
+    protocol->store_long((longlong) thd->last_binlog_pos);
+  } else {
+    protocol->store_null();
+    protocol->store_null();
+  }
+  if (protocol->write())
+  {
+    DBUG_RETURN(-1);
+  }
+
+  send_eof(thd);
+  DBUG_RETURN(0);
+}
+
 
 /***************************************************************************
 ** List all tables in a database (fast version)
diff -ur -x '*sql_yacc.cc' -x '*fill_help*' -x '*mysqlbug*' -x '*sql_yacc.h' mysql-4.1.3-beta/sql/sql_yacc.yy mysql-4.1.3-lastbinlog/sql/sql_yacc.yy
--- mysql-4.1.3-beta/sql/sql_yacc.yy	2004-06-27 14:56:51.000000000 -0700
+++ mysql-4.1.3-lastbinlog/sql/sql_yacc.yy	2004-07-20 13:34:08.000000000 -0700
@@ -266,6 +266,7 @@
 %token	JOIN_SYM
 %token	KEYS
 %token	KEY_SYM
+%token	LAST_BINLOG_EVENT_SYM
 %token	LEADING
 %token	LEAST_SYM
 %token	LEAVES
@@ -4319,6 +4320,8 @@
           { Lex->sql_command = SQLCOM_SHOW_INNODB_STATUS; WARN_DEPRECATED("SHOW INNODB STATUS", "SHOW ENGINE INNODB STATUS"); }
 	| opt_full PROCESSLIST_SYM
 	  { Lex->sql_command= SQLCOM_SHOW_PROCESSLIST;}
+	| opt_full LAST_BINLOG_EVENT_SYM
+	  { Lex->sql_command= SQLCOM_SHOW_LAST_BINLOG_EVENT;}
 	| opt_var_type VARIABLES wild
 	  {
 	    THD *thd= YYTHD;