diff --git a/qse/cmd/sed/sed.c b/qse/cmd/sed/sed.c
index 504330e2..b50d48a2 100644
--- a/qse/cmd/sed/sed.c
+++ b/qse/cmd/sed/sed.c
@@ -558,14 +558,13 @@ static void trace_exec (qse_sed_t* sed, qse_sed_exec_op_t op, const qse_sed_cmd_
 {
 	switch (op)
 	{
-#if 0
 		case QSE_SED_EXEC_READ:
-			qse_fprintf (QSE_STDERR, QSE_T("reading...\n"));
+			/*qse_fprintf (QSE_STDERR, QSE_T("reading...\n"));*/
 			break;
 		case QSE_SED_EXEC_WRITE:
-			qse_fprintf (QSE_STDERR, QSE_T("wrting...\n"));
+			/*qse_fprintf (QSE_STDERR, QSE_T("wrting...\n"));*/
 			break;
-#endif
+
 		/* TODO: use function to get hold space and pattern space and print them */
 
 		case QSE_SED_EXEC_MATCH:
diff --git a/qse/include/qse/awk/Awk.hpp b/qse/include/qse/awk/Awk.hpp
index 76b3941e..a8633ebf 100644
--- a/qse/include/qse/awk/Awk.hpp
+++ b/qse/include/qse/awk/Awk.hpp
@@ -1171,7 +1171,7 @@ private:
 
 	int dispatch_function (Run* run, const cstr_t* name);
 
-	static const char_t* xerrstr (awk_t* a, errnum_t num);
+	static const char_t* xerrstr (const awk_t* a, errnum_t num);
 
 private:
 	Awk (const Awk&);
diff --git a/qse/include/qse/awk/awk.h b/qse/include/qse/awk/awk.h
index 0c9e9a0c..9a9fc6e8 100644
--- a/qse/include/qse/awk/awk.h
+++ b/qse/include/qse/awk/awk.h
@@ -999,7 +999,7 @@ typedef struct qse_awk_errinf_t qse_awk_errinf_t;
  * object with the qse_awk_seterrstr() function to customize an error string.
  */
 typedef const qse_char_t* (*qse_awk_errstr_t) (
-	qse_awk_t*       awk,   /**< awk */
+	const qse_awk_t* awk,   /**< awk */
 	qse_awk_errnum_t num    /**< error number */
 );
 
@@ -1205,7 +1205,7 @@ int qse_awk_clear (
  * The qse_awk_geterrstr() gets an error string getter.
  */
 qse_awk_errstr_t qse_awk_geterrstr (
-	qse_awk_t*       awk    /**< awk */
+	const qse_awk_t* awk    /**< awk */
 );
 
 /**
@@ -1243,7 +1243,7 @@ void qse_awk_seterrstr (
  * @return error number
  */
 qse_awk_errnum_t qse_awk_geterrnum (
-	qse_awk_t* awk /**< awk */
+	const qse_awk_t* awk /**< awk */
 );
 
 /**
@@ -1251,7 +1251,7 @@ qse_awk_errnum_t qse_awk_geterrnum (
  * last error has occurred.
  */
 const qse_awk_loc_t* qse_awk_geterrloc (
-	qse_awk_t* awk /**< awk */
+	const qse_awk_t* awk /**< awk */
 );
 
 /**
@@ -1261,7 +1261,7 @@ const qse_awk_loc_t* qse_awk_geterrloc (
  * @return error message
  */
 const qse_char_t* qse_awk_geterrmsg (
-	qse_awk_t* awk /**< awk */
+	const qse_awk_t* awk /**< awk */
 );
 
 /**
@@ -1269,7 +1269,7 @@ const qse_char_t* qse_awk_geterrmsg (
  * pointed to by @a errinf from @a awk.
  */
 void qse_awk_geterrinf (
-	qse_awk_t*        awk,   /**< awk */
+	const qse_awk_t*  awk,   /**< awk */
 	qse_awk_errinf_t* errinf /**< error information buffer */
 );
 
@@ -1300,7 +1300,7 @@ void qse_awk_seterrinf (
  * The qse_awk_geterror() function gets error information via parameters.
  */
 void qse_awk_geterror (
-	qse_awk_t*         awk,    /**< awk */
+	const qse_awk_t*   awk,    /**< awk */
 	qse_awk_errnum_t*  errnum, /**< error number */
 	const qse_char_t** errmsg, /**< error message */
 	qse_awk_loc_t*     errloc  /**< error location */
@@ -1322,7 +1322,7 @@ void qse_awk_seterror (
  * @return 0 or a number ORed of #qse_awk_option_t enumerators.
  */
 int qse_awk_getoption (
-	qse_awk_t* awk /**< awk */
+	const qse_awk_t* awk /**< awk */
 );
 
 /**
@@ -1340,8 +1340,8 @@ void qse_awk_setoption (
  * @return maximum depth
  */
 qse_size_t qse_awk_getmaxdepth (
-	qse_awk_t*      awk, /**< awk */
-	qse_awk_depth_t type /**< operation type */
+	const qse_awk_t* awk, /**< awk */
+	qse_awk_depth_t  type /**< operation type */
 );
 
 /**
@@ -1797,7 +1797,7 @@ qse_htb_t* qse_awk_rtx_getnvmap (
  * @return error number
  */
 qse_awk_errnum_t qse_awk_rtx_geterrnum (
-	qse_awk_rtx_t* rtx /**< runtime context */
+	const qse_awk_rtx_t* rtx /**< runtime context */
 );
 
 /**
@@ -1806,7 +1806,7 @@ qse_awk_errnum_t qse_awk_rtx_geterrnum (
  * @return error location
  */
 const qse_awk_loc_t* qse_awk_rtx_geterrloc (
-	qse_awk_rtx_t* rtx /**< runtime context */
+	const qse_awk_rtx_t* rtx /**< runtime context */
 );
 
 /**
@@ -1815,7 +1815,7 @@ const qse_awk_loc_t* qse_awk_rtx_geterrloc (
  * @return error message
  */
 const qse_char_t* qse_awk_rtx_geterrmsg (
-	qse_awk_rtx_t* rtx /**< runtime context */
+	const qse_awk_rtx_t* rtx /**< runtime context */
 );
 
 /**
@@ -1823,8 +1823,8 @@ const qse_char_t* qse_awk_rtx_geterrmsg (
  * pointed to by @a errinf from a runtime context @a rtx.
  */
 void qse_awk_rtx_geterrinf (
-	qse_awk_rtx_t*    rtx,   /**< runtime context */
-	qse_awk_errinf_t* errinf /**< error information */
+	const qse_awk_rtx_t* rtx,   /**< runtime context */
+	qse_awk_errinf_t*    errinf /**< error information */
 );
 
 /**
@@ -1834,10 +1834,10 @@ void qse_awk_rtx_geterrinf (
  * @a errmsg; the error line into memory pointed to by @a errlin.
  */
 void qse_awk_rtx_geterror (
-	qse_awk_rtx_t*     rtx,    /**< runtime context */
-	qse_awk_errnum_t*  errnum, /**< error number */
-	const qse_char_t** errmsg, /**< error message */
-	qse_awk_loc_t*     errloc  /**< error location */
+	const qse_awk_rtx_t* rtx,    /**< runtime context */
+	qse_awk_errnum_t*    errnum, /**< error number */
+	const qse_char_t**   errmsg, /**< error message */
+	qse_awk_loc_t*       errloc  /**< error location */
 );
 
 /** 
diff --git a/qse/include/qse/cmn/fio.h b/qse/include/qse/cmn/fio.h
index 29d4223b..b54e75cd 100644
--- a/qse/include/qse/cmn/fio.h
+++ b/qse/include/qse/cmn/fio.h
@@ -210,15 +210,19 @@ void qse_fio_fini (
 	qse_fio_t* fio
 );
 
+qse_fio_errnum_t qse_fio_geterrnum (
+	const qse_fio_t* fio
+);
+
 /**
  * The qse_fio_gethandle() function returns the native file handle.
  */
 qse_fio_hnd_t qse_fio_gethandle (
-	qse_fio_t* fio
+	const qse_fio_t* fio
 );
 
 qse_ubi_t qse_fio_gethandleasubi (
-	qse_fio_t* fio
+	const qse_fio_t* fio
 );
 
 /**
diff --git a/qse/include/qse/cmn/htb.h b/qse/include/qse/cmn/htb.h
index cdbf10b8..3047b02d 100644
--- a/qse/include/qse/cmn/htb.h
+++ b/qse/include/qse/cmn/htb.h
@@ -121,11 +121,11 @@ typedef void (*qse_htb_freeer_t) (
  * integer otherwise.
  */
 typedef int (*qse_htb_comper_t) (
-	qse_htb_t*  htb,    /**< hash table */ 
-	const void* kptr1,  /**< key pointer */
-	qse_size_t  klen1,  /**< key length */ 
-	const void* kptr2,  /**< key pointer */ 
-	qse_size_t  klen2   /**< key length */
+	const qse_htb_t* htb,    /**< hash table */ 
+	const void*      kptr1,  /**< key pointer */
+	qse_size_t       klen1,  /**< key length */ 
+	const void*      kptr2,  /**< key pointer */ 
+	qse_size_t       klen2   /**< key length */
 );
 
 /**
@@ -154,9 +154,9 @@ typedef qse_size_t (*qse_htb_sizer_t) (
  * The qse_htb_hasher_t type defines a key hash function
  */
 typedef qse_size_t (*qse_htb_hasher_t) (
-	qse_htb_t*  htb,   /**< hash table */
-	const void* kptr,  /**< key pointer */
-	qse_size_t  klen   /**< key length in bytes */
+	const qse_htb_t*  htb,   /**< hash table */
+	const void*       kptr,  /**< key pointer */
+	qse_size_t        klen   /**< key length in bytes */
 );
 
 /**
@@ -361,7 +361,7 @@ void qse_htb_fini (
  * The qse_htb_getmancbs() function gets manipulation callback function set.
  */
 const qse_htb_mancbs_t* qse_htb_getmancbs (
-	qse_htb_t* htb /**< hash table */
+	const qse_htb_t* htb /**< hash table */
 );
 
 /**
@@ -377,7 +377,7 @@ void qse_htb_setmancbs (
  * The qse_htb_getsize() function gets the number of pairs in hash table.
  */
 qse_size_t qse_htb_getsize (
-	qse_htb_t* htb
+	const qse_htb_t* htb
 );
 
 /**
@@ -385,7 +385,7 @@ qse_size_t qse_htb_getsize (
  * in a hash bucket.
  */
 qse_size_t qse_htb_getcapa (
-	qse_htb_t* htb /**< hash table */
+	const qse_htb_t* htb /**< hash table */
 );
 
 /**
@@ -396,9 +396,9 @@ qse_size_t qse_htb_getcapa (
  *         or #QSE_NULL if no match is found.
  */
 qse_htb_pair_t* qse_htb_search (
-	qse_htb_t*  htb,   /**< hash table */
-	const void* kptr,  /**< key pointer */
-	qse_size_t  klen   /**< key length */
+	const qse_htb_t* htb,   /**< hash table */
+	const void*      kptr,  /**< key pointer */
+	qse_size_t       klen   /**< key length */
 );
 
 /**
@@ -632,20 +632,20 @@ void qse_htb_freepair (
  * The qse_htb_dflhash() function is a default hash function.
  */
 qse_size_t qse_htb_dflhash (
-	qse_htb_t*  htb,
-	const void* kptr,
-	qse_size_t  klen
+	const qse_htb_t*  htb,
+	const void*       kptr,
+	qse_size_t        klen
 );
 
 /**
  * The qse_htb_dflcomp() function is default comparator.
  */
 int qse_htb_dflcomp (
-	qse_htb_t*  htb,
-	const void* kptr1,
-	qse_size_t  klen1,
-	const void* kptr2,
-	qse_size_t  klen2
+	const qse_htb_t* htb,
+	const void*      kptr1,
+	qse_size_t       klen1,
+	const void*      kptr2,
+	qse_size_t       klen2
 );
 
 #ifdef __cplusplus
diff --git a/qse/include/qse/cmn/ipad.h b/qse/include/qse/cmn/ipad.h
index 6246c4ef..92060a20 100644
--- a/qse/include/qse/cmn/ipad.h
+++ b/qse/include/qse/cmn/ipad.h
@@ -1,4 +1,3 @@
-
 /*
  * $Id$
  *
@@ -25,7 +24,7 @@
 #include <qse/types.h>
 #include <qse/macros.h>
 
-typedef struct qse_ipad_t qse_ipad_t;
+typedef struct qse_ipad_t  qse_ipad_t;
 typedef struct qse_ipad4_t qse_ipad4_t;
 typedef struct qse_ipad6_t qse_ipad6_t;
 
@@ -44,14 +43,14 @@ struct qse_ipad_t
 {
 	enum
 	{
-		QSE_IPAD_IP4,
-		QSE_IPAD_IP6
+		QSE_IPAD_V4,
+		QSE_IPAD_V6
 	} type;
 
 	union
 	{
-		qse_ipad4_t ip4;
-		qse_ipad4_t ip6;
+		qse_ipad4_t v4;
+		qse_ipad6_t v6;
 	} u;
 };
 
@@ -59,6 +58,38 @@ struct qse_ipad_t
 extern "C" {
 #endif
 
+int qse_mbstoipad4 (
+	const qse_mchar_t* mbs,
+	qse_ipad4_t*       ipad
+);
+
+int qse_mbsntoipad4 (
+	const qse_mchar_t* mbs,
+	qse_size_t         len
+);
+
+int qse_ipad4tombs (
+	const qse_ipad4_t* ipad,
+	qse_mchar_t*       mbs,
+	qse_size_t         len
+);
+
+int qse_wcstoipad4 (
+	const qse_wchar_t* wcs,
+	qse_ipad4_t*       ipad
+);
+
+int qse_wcstoipad4 (
+	const qse_wchar_t* wcs,
+	qse_ipad4_t*       ipad
+);
+
+int qse_ipad4towcs (
+	const qse_ipad4_t* ipad,
+	qse_wchar_t*       wcs,
+	qse_size_t         len
+);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/qse/include/qse/cmn/pio.h b/qse/include/qse/cmn/pio.h
index 7b53f20b..3155f2f9 100644
--- a/qse/include/qse/cmn/pio.h
+++ b/qse/include/qse/cmn/pio.h
@@ -263,12 +263,21 @@ void qse_pio_fini (
 	qse_pio_t* pio /**< pio object */
 );
 
+/**
+ * The qse_pio_geterrnum() function returns the number of the last error 
+ * occurred. 
+ * @return error number
+ */
+qse_pio_errnum_t qse_pio_geterrnum (
+	const qse_pio_t* pio /**< pio object */
+);
+
 /**
  * The qse_pio_getoption() function gets the current option.
  * @return option number OR'ed of #qse_pio_option_t enumerators
  */
 int qse_pio_getoption (
-	qse_pio_t* pio    /**< pio object */
+	const qse_pio_t* pio    /**< pio object */
 );
 
 /**
@@ -280,15 +289,6 @@ void qse_pio_setoption (
 	                     enumerators */
 );
 
-/**
- * The qse_pio_geterrnum() function returns the number of the last error 
- * occurred. 
- * @return error number
- */
-qse_pio_errnum_t qse_pio_geterrnum (
-	qse_pio_t* pio /**< pio object */
-);
-
 /**
  * The qse_pio_getcmgr() function returns the current character manager.
  * It returns #QSE_NULL is @a pio is not opened with #QSE_PIO_TEXT.
@@ -313,8 +313,8 @@ void qse_pio_setcmgr (
  * @return pipe handle
  */
 qse_pio_hnd_t qse_pio_gethandle (
-	qse_pio_t*    pio, /**< pio object */
-	qse_pio_hid_t hid  /**< handle ID */
+	const qse_pio_t* pio, /**< pio object */
+	qse_pio_hid_t    hid  /**< handle ID */
 );
 
 /**
@@ -323,8 +323,8 @@ qse_pio_hnd_t qse_pio_gethandle (
  * @return pipe handle
  */
 qse_ubi_t qse_pio_gethandleasubi (
-	qse_pio_t*    pio, /**< pio object */
-	qse_pio_hid_t hid  /**< handle ID */
+	const qse_pio_t* pio, /**< pio object */
+	qse_pio_hid_t    hid  /**< handle ID */
 );
 
 /**
@@ -332,7 +332,7 @@ qse_ubi_t qse_pio_gethandleasubi (
  * @return process handle
  */
 qse_pio_pid_t qse_pio_getchild (
-	qse_pio_t*    pio /**< pio object */
+	const qse_pio_t* pio /**< pio object */
 );
 
 /**
diff --git a/qse/include/qse/cmn/rbt.h b/qse/include/qse/cmn/rbt.h
index 8be88ac1..e7aebe58 100644
--- a/qse/include/qse/cmn/rbt.h
+++ b/qse/include/qse/cmn/rbt.h
@@ -116,11 +116,11 @@ typedef void (*qse_rbt_freeer_t) (
  * key is greater than the second key, -1 otherwise.
  */
 typedef int (*qse_rbt_comper_t) (
-	qse_rbt_t*  rbt,    /**< red-black tree */ 
-	const void* kptr1,  /**< key pointer */
-	qse_size_t  klen1,  /**< key length */ 
-	const void* kptr2,  /**< key pointer */
-	qse_size_t  klen2   /**< key length */
+	const qse_rbt_t* rbt,    /**< red-black tree */ 
+	const void*      kptr1,  /**< key pointer */
+	qse_size_t       klen1,  /**< key length */ 
+	const void*      kptr2,  /**< key pointer */
+	qse_size_t       klen2   /**< key length */
 );
 
 /**
@@ -319,7 +319,7 @@ void qse_rbt_fini (
  * The qse_rbt_getmancbs() function gets manipulation callback function set.
  */
 const qse_rbt_mancbs_t* qse_rbt_getmancbs (
-	qse_rbt_t* rbt /**< red-black tree */
+	const qse_rbt_t* rbt /**< red-black tree */
 );
 
 /**
@@ -335,7 +335,7 @@ void qse_rbt_setmancbs (
  * The qse_rbt_getsize() function gets the number of pairs in red-black tree.
  */
 qse_size_t qse_rbt_getsize (
-	qse_rbt_t* rbt  /**< red-black tree */
+	const qse_rbt_t* rbt  /**< red-black tree */
 );
 
 /**
@@ -346,9 +346,9 @@ qse_size_t qse_rbt_getsize (
  *         or QSE_NULL if no match is found.
  */
 qse_rbt_pair_t* qse_rbt_search (
-	qse_rbt_t*  rbt,   /**< red-black tree */
-	const void* kptr,  /**< key pointer */
-	qse_size_t  klen   /**< the size of the key */
+	const qse_rbt_t* rbt,   /**< red-black tree */
+	const void*      kptr,  /**< key pointer */
+	qse_size_t       klen   /**< the size of the key */
 );
 
 /**
@@ -574,11 +574,11 @@ void qse_rbt_freepair (
  * The qse_rbt_dflcomp() function defines the default key comparator.
  */
 int qse_rbt_dflcomp (
-	qse_rbt_t*  rbt,
-	const void* kptr1,
-	qse_size_t  klen1,
-	const void* kptr2,
-	qse_size_t  klen2
+	const qse_rbt_t* rbt,
+	const void*      kptr1,
+	qse_size_t       klen1,
+	const void*      kptr2,
+	qse_size_t       klen2
 );
 
 #ifdef __cplusplus
diff --git a/qse/include/qse/cmn/rex.h b/qse/include/qse/cmn/rex.h
index e0fa5c42..ef400d52 100644
--- a/qse/include/qse/cmn/rex.h
+++ b/qse/include/qse/cmn/rex.h
@@ -238,7 +238,7 @@ qse_rex_node_t* qse_rex_yield (
  * The qse_rex_getoption() function returns the current options.
  */
 int qse_rex_getoption (
-	qse_rex_t* rex /**< regular expression processor */
+	const qse_rex_t* rex /**< regular expression processor */
 );
 
 /**
@@ -250,11 +250,11 @@ void qse_rex_setoption (
 );
 
 qse_rex_errnum_t qse_rex_geterrnum (
-	qse_rex_t* rex
+	const qse_rex_t* rex
 );
 
 const qse_char_t* qse_rex_geterrmsg (
-	qse_rex_t* rex
+	const qse_rex_t* rex
 );
 
 qse_rex_node_t* qse_rex_comp (
diff --git a/qse/include/qse/cmn/sio.h b/qse/include/qse/cmn/sio.h
index 95b40d49..1593cb69 100644
--- a/qse/include/qse/cmn/sio.h
+++ b/qse/include/qse/cmn/sio.h
@@ -197,7 +197,7 @@ void qse_sio_fini (
 );
 
 qse_sio_errnum_t qse_sio_geterrnum (
-	qse_sio_t* sio
+	const qse_sio_t* sio
 );
 
 qse_cmgr_t* qse_sio_getcmgr (
@@ -210,11 +210,11 @@ void qse_sio_setcmgr (
 );
 
 qse_sio_hnd_t qse_sio_gethandle (
-	qse_sio_t* sio
+	const qse_sio_t* sio
 );
 
 qse_ubi_t qse_sio_gethandleasubi (
-	qse_sio_t* sio
+	const qse_sio_t* sio
 );
 
 qse_ssize_t qse_sio_flush (
diff --git a/qse/include/qse/cmn/tio.h b/qse/include/qse/cmn/tio.h
index 290691ca..d24efef3 100644
--- a/qse/include/qse/cmn/tio.h
+++ b/qse/include/qse/cmn/tio.h
@@ -169,7 +169,7 @@ int qse_tio_fini (
  * The qse_tio_geterrnum() function returns the current error code.
  */
 qse_tio_errnum_t qse_tio_geterrnum (
-	qse_tio_t* tio
+	const qse_tio_t* tio
 );
 
 /**
diff --git a/qse/include/qse/sed/Sed.hpp b/qse/include/qse/sed/Sed.hpp
index d6d49f07..f1f48d25 100644
--- a/qse/include/qse/sed/Sed.hpp
+++ b/qse/include/qse/sed/Sed.hpp
@@ -316,7 +316,7 @@ private:
 		sed_t* s, io_cmd_t cmd, io_arg_t* arg, char_t* buf, size_t len);
 	static ssize_t xout (
 		sed_t* s, io_cmd_t cmd, io_arg_t* arg, char_t* dat, size_t len);
-	static const char_t* xerrstr (sed_t* s, errnum_t num);
+	static const char_t* xerrstr (const sed_t* s, errnum_t num);
 
 private:
 	Sed (const Sed&);
diff --git a/qse/include/qse/sed/sed.h b/qse/include/qse/sed/sed.h
index 86a81d18..3f468eb9 100644
--- a/qse/include/qse/sed/sed.h
+++ b/qse/include/qse/sed/sed.h
@@ -234,7 +234,7 @@ typedef enum qse_sed_errnum_t qse_sed_errnum_t;
  * editor with the qse_sed_seterrstr() function to customize an error string.
  */
 typedef const qse_char_t* (*qse_sed_errstr_t) (
-	qse_sed_t*       sed,   /**< stream editor */
+	const qse_sed_t* sed,   /**< stream editor */
 	qse_sed_errnum_t num    /**< an error number */
 );
 
@@ -355,7 +355,7 @@ void qse_sed_close (
  * @return 0 or a number OR'ed of #qse_sed_option_t values 
  */
 int qse_sed_getoption (
-	qse_sed_t* sed /**< stream editor */
+	const qse_sed_t* sed /**< stream editor */
 );
 
 /**
@@ -370,7 +370,7 @@ void qse_sed_setoption (
  * The qse_sed_geterrstr() gets an error string getter.
  */
 qse_sed_errstr_t qse_sed_geterrstr (
-	qse_sed_t*       sed    /**< stream editor */
+	const qse_sed_t* sed    /**< stream editor */
 );
 
 /**
@@ -407,7 +407,7 @@ void qse_sed_seterrstr (
  * @return the number of the last error
  */
 qse_sed_errnum_t qse_sed_geterrnum (
-	qse_sed_t* sed /**< stream editor */
+	const qse_sed_t* sed /**< stream editor */
 );
 
 /**
@@ -416,7 +416,7 @@ qse_sed_errnum_t qse_sed_geterrnum (
  * @return error location
  */
 const qse_sed_loc_t* qse_sed_geterrloc (
-	qse_sed_t* sed /**< stream editor */
+	const qse_sed_t* sed /**< stream editor */
 );
 
 /**
@@ -424,7 +424,7 @@ const qse_sed_loc_t* qse_sed_geterrloc (
  * @return a pointer to an error message
  */
 const qse_char_t* qse_sed_geterrmsg (
-	qse_sed_t* sed /**< stream editor */
+	const qse_sed_t* sed /**< stream editor */
 );
 
 /**
@@ -433,7 +433,7 @@ const qse_char_t* qse_sed_geterrmsg (
  * to by each parameter.
  */
 void qse_sed_geterror (
-	qse_sed_t*         sed,    /**< stream editor */
+	const qse_sed_t*   sed,    /**< stream editor */
 	qse_sed_errnum_t*  errnum, /**< error number */
 	const qse_char_t** errmsg, /**< error message */
 	qse_sed_loc_t*     errloc  /**< error location */
diff --git a/qse/lib/awk/Awk.cpp b/qse/lib/awk/Awk.cpp
index 5ea96875..a5f122cf 100644
--- a/qse/lib/awk/Awk.cpp
+++ b/qse/lib/awk/Awk.cpp
@@ -979,7 +979,7 @@ const Awk::char_t* Awk::getErrorString (errnum_t num) const
 	return dflerrstr (awk, num);
 }
 
-const Awk::char_t* Awk::xerrstr (awk_t* a, errnum_t num) 
+const Awk::char_t* Awk::xerrstr (const awk_t* a, errnum_t num) 
 {
 	Awk* awk = *(Awk**)QSE_XTN(a);
 	return awk->getErrorString (num);
diff --git a/qse/lib/awk/awk.c b/qse/lib/awk/awk.c
index 584a559c..bba5e005 100644
--- a/qse/lib/awk/awk.c
+++ b/qse/lib/awk/awk.c
@@ -376,7 +376,7 @@ qse_awk_prm_t* qse_awk_getprm (qse_awk_t* awk)
 	return &awk->prm;
 }
 
-int qse_awk_getoption (qse_awk_t* awk)
+int qse_awk_getoption (const qse_awk_t* awk)
 {
 	return awk->option;
 }
@@ -391,7 +391,7 @@ void qse_awk_stopall (qse_awk_t* awk)
 	awk->stopall = QSE_TRUE;
 }
 
-qse_size_t qse_awk_getmaxdepth (qse_awk_t* awk, qse_awk_depth_t type)
+qse_size_t qse_awk_getmaxdepth (const qse_awk_t* awk, qse_awk_depth_t type)
 {
 	return (type == QSE_AWK_DEPTH_BLOCK_PARSE)? awk->parse.depth.max.block:
 	       (type == QSE_AWK_DEPTH_BLOCK_RUN)? awk->run.depth.max.block:
diff --git a/qse/lib/awk/err.c b/qse/lib/awk/err.c
index 389084e8..773e367b 100644
--- a/qse/lib/awk/err.c
+++ b/qse/lib/awk/err.c
@@ -154,7 +154,7 @@ const qse_char_t* qse_awk_dflerrstr (qse_awk_t* awk, qse_awk_errnum_t errnum)
 		errstr[errnum]: QSE_T("unknown error");
 }
 
-qse_awk_errstr_t qse_awk_geterrstr (qse_awk_t* awk)
+qse_awk_errstr_t qse_awk_geterrstr (const qse_awk_t* awk)
 {
 	return awk->errstr;
 }
@@ -164,23 +164,23 @@ void qse_awk_seterrstr (qse_awk_t* awk, qse_awk_errstr_t errstr)
 	awk->errstr = errstr;
 }
 
-qse_awk_errnum_t qse_awk_geterrnum (qse_awk_t* awk)
+qse_awk_errnum_t qse_awk_geterrnum (const qse_awk_t* awk)
 {
 	return awk->errinf.num;
 }
 
-const qse_awk_loc_t* qse_awk_geterrloc (qse_awk_t* awk)
+const qse_awk_loc_t* qse_awk_geterrloc (const qse_awk_t* awk)
 {
 	return &awk->errinf.loc;
 }
 
-const qse_char_t* qse_awk_geterrmsg (qse_awk_t* awk)
+const qse_char_t* qse_awk_geterrmsg (const qse_awk_t* awk)
 {
 	return (awk->errinf.msg[0] == QSE_T('\0'))?
 		qse_awk_geterrstr(awk)(awk,awk->errinf.num): awk->errinf.msg;
 }
 
-void qse_awk_geterrinf (qse_awk_t* awk, qse_awk_errinf_t* errinf)
+void qse_awk_geterrinf (const qse_awk_t* awk, qse_awk_errinf_t* errinf)
 {
 	QSE_MEMCPY (errinf, &awk->errinf, QSE_SIZEOF(*errinf));
 	if (errinf->msg[0] == QSE_T('\0'))
@@ -191,7 +191,7 @@ void qse_awk_geterrinf (qse_awk_t* awk, qse_awk_errinf_t* errinf)
 }
 
 void qse_awk_geterror (
-	qse_awk_t* awk, qse_awk_errnum_t* errnum, 
+	const qse_awk_t* awk, qse_awk_errnum_t* errnum, 
 	const qse_char_t** errmsg, qse_awk_loc_t* errloc)
 {
 	if (errnum != QSE_NULL) *errnum = awk->errinf.num;
@@ -234,23 +234,23 @@ void qse_awk_seterror (
 	if (errloc != QSE_NULL) awk->errinf.loc = *errloc;
 }
 
-qse_awk_errnum_t qse_awk_rtx_geterrnum (qse_awk_rtx_t* rtx)
+qse_awk_errnum_t qse_awk_rtx_geterrnum (const qse_awk_rtx_t* rtx)
 {
 	return rtx->errinf.num;
 }
 
-const qse_awk_loc_t* qse_awk_rtx_geterrloc (qse_awk_rtx_t* rtx)
+const qse_awk_loc_t* qse_awk_rtx_geterrloc (const qse_awk_rtx_t* rtx)
 {
 	return &rtx->errinf.loc;
 }
 
-const qse_char_t* qse_awk_rtx_geterrmsg (qse_awk_rtx_t* rtx)
+const qse_char_t* qse_awk_rtx_geterrmsg (const qse_awk_rtx_t* rtx)
 {
 	return (rtx->errinf.msg[0] == QSE_T('\0')) ?
 		qse_awk_geterrstr(rtx->awk)(rtx->awk,rtx->errinf.num): rtx->errinf.msg;
 }
 
-void qse_awk_rtx_geterrinf (qse_awk_rtx_t* rtx, qse_awk_errinf_t* errinf)
+void qse_awk_rtx_geterrinf (const qse_awk_rtx_t* rtx, qse_awk_errinf_t* errinf)
 {
 	QSE_MEMCPY (errinf, &rtx->errinf, QSE_SIZEOF(*errinf));
 	if (errinf->msg[0] == QSE_T('\0'))
@@ -261,7 +261,7 @@ void qse_awk_rtx_geterrinf (qse_awk_rtx_t* rtx, qse_awk_errinf_t* errinf)
 }
 
 void qse_awk_rtx_geterror (
-	qse_awk_rtx_t* rtx, qse_awk_errnum_t* errnum, 
+	const qse_awk_rtx_t* rtx, qse_awk_errnum_t* errnum, 
 	const qse_char_t** errmsg, qse_awk_loc_t* errloc)
 {
 	if (errnum != QSE_NULL) *errnum = rtx->errinf.num;
diff --git a/qse/lib/awk/std.c b/qse/lib/awk/std.c
index 6cf21634..5f158bf4 100644
--- a/qse/lib/awk/std.c
+++ b/qse/lib/awk/std.c
@@ -449,11 +449,13 @@ static qse_ssize_t sf_in_open (
 				xtn->s.in.u.str.ptr = xtn->s.in.x->u.str.ptr;
 				xtn->s.in.u.str.end = xtn->s.in.x->u.str.ptr + xtn->s.in.x->u.str.len;
 				return 1;
+
+			default:
+				/* this should never happen */
+				qse_awk_seterrnum (awk, QSE_AWK_EINTERN, QSE_NULL);
+				return -1;
 		}
 
-		/* this should never happen */
-		qse_awk_seterrnum (awk, QSE_AWK_EINTERN, QSE_NULL);
-		return -1;
 	}
 	else
 	{
@@ -522,6 +524,10 @@ static qse_ssize_t sf_in_close (
 			case QSE_AWK_PARSESTD_STR:
 				/* nothing to close */
 				break;
+
+			default:
+				/* nothing to close */
+				break;
 		}
 	}
 	else
@@ -574,10 +580,13 @@ static qse_ssize_t sf_in_read (
 				}
 				return n;
 			}
+
+			default:
+				/* this should never happen */
+				qse_awk_seterrnum (awk, QSE_AWK_EINTERN, QSE_NULL);
+				return -1;
 		}
 
-		qse_awk_seterrnum (awk, QSE_AWK_EINTERN, QSE_NULL);
-		return -1;
 	}
 	else
 	{
@@ -613,10 +622,10 @@ static qse_ssize_t sf_in (
 		case QSE_AWK_SIO_READ:
 			return sf_in_read (awk, arg, data, size, xtn);
 
+		default:
+			qse_awk_seterrnum (awk, QSE_AWK_EINTERN, QSE_NULL);
+			return -1;
 	}
-
-	qse_awk_seterrnum (awk, QSE_AWK_EINTERN, QSE_NULL);
-	return -1;
 }
 
 static qse_ssize_t sf_out (
diff --git a/qse/lib/cmn/fio.c b/qse/lib/cmn/fio.c
index c44bb1f1..3cdcd505 100644
--- a/qse/lib/cmn/fio.c
+++ b/qse/lib/cmn/fio.c
@@ -737,12 +737,17 @@ void qse_fio_fini (qse_fio_t* fio)
 	}
 }
 
-qse_fio_hnd_t qse_fio_gethandle (qse_fio_t* fio)
+qse_fio_errnum_t qse_fio_geterrnum (const qse_fio_t* fio)
+{
+	return fio->errnum;
+}
+
+qse_fio_hnd_t qse_fio_gethandle (const qse_fio_t* fio)
 {
 	return fio->handle;
 }
 
-qse_ubi_t qse_fio_gethandleasubi (qse_fio_t* fio)
+qse_ubi_t qse_fio_gethandleasubi (const qse_fio_t* fio)
 {
 	qse_ubi_t handle;
 
diff --git a/qse/lib/cmn/htb.c b/qse/lib/cmn/htb.c
index 12a95981..d26c974b 100644
--- a/qse/lib/cmn/htb.c
+++ b/qse/lib/cmn/htb.c
@@ -322,7 +322,7 @@ void qse_htb_fini (htb_t* htb)
 	QSE_MMGR_FREE (htb->mmgr, htb->bucket);
 }
 
-const mancbs_t* qse_htb_getmancbs (htb_t* htb)
+const mancbs_t* qse_htb_getmancbs (const htb_t* htb)
 {
 	return htb->mancbs;
 }
@@ -333,17 +333,17 @@ void qse_htb_setmancbs (htb_t* htb, const mancbs_t* mancbs)
 	htb->mancbs = mancbs;
 }
 
-size_t qse_htb_getsize (htb_t* htb)
+size_t qse_htb_getsize (const htb_t* htb)
 {
 	return htb->size;
 }
 
-size_t qse_htb_getcapa (htb_t* htb)
+size_t qse_htb_getcapa (const htb_t* htb)
 {
 	return htb->capa;
 }
 
-pair_t* qse_htb_search (htb_t* htb, const void* kptr, size_t klen)
+pair_t* qse_htb_search (const htb_t* htb, const void* kptr, size_t klen)
 {
 	pair_t* pair;
 	size_t hc;
@@ -709,7 +709,8 @@ pair_t* qse_htb_getnextpair (htb_t* htb, pair_t* pair, size_t* buckno)
 	return QSE_NULL;
 }
 
-size_t qse_htb_dflhash (htb_t* htb, const void* kptr, size_t klen)
+size_t qse_htb_dflhash (
+	const htb_t* htb, const void* kptr, size_t klen)
 {
 	/*size_t h = 2166136261;*/
 	/*size_t h = 0;*/
@@ -727,7 +728,8 @@ size_t qse_htb_dflhash (htb_t* htb, const void* kptr, size_t klen)
 	return h ; 
 }
 
-int qse_htb_dflcomp (htb_t* htb, 
+int qse_htb_dflcomp (
+	const htb_t* htb, 
 	const void* kptr1, size_t klen1, 
 	const void* kptr2, size_t klen2)
 {
diff --git a/qse/lib/cmn/ipad.c b/qse/lib/cmn/ipad.c
index abd7c464..cf2304ca 100644
--- a/qse/lib/cmn/ipad.c
+++ b/qse/lib/cmn/ipad.c
@@ -35,6 +35,9 @@
  */
 
 #include <qse/cmn/ipad.h>
+#include <qse/cmn/hton.h>
+#include <qse/cmn/str.h>
+#include "mem.h"
 
 #if 0
 const qse_ipad4_t qse_ipad4_any =
@@ -64,7 +67,6 @@ const qse_ipad6_t qse_ipad6_loopback =
 };
 #endif
 
-#if 0
 int qse_strtoipad4 (const qse_char_t* str, qse_ipad4_t* ipad)
 {
 	qse_char_t c;
@@ -218,7 +220,7 @@ int qse_strtoipad6 (const qse_char_t* src, qse_ipad6_t* ipad)
 	int saw_xdigit;
 	unsigned int val;
 
-	qse_memset (&tmp, 0, QSE_SIZEOF(tmp));
+	QSE_MEMSET (&tmp, 0, QSE_SIZEOF(tmp));
 	tp = &tmp.value[0];
 	endp = &tmp.value[QSE_COUNTOF(tmp.value)];
 	colonp = QSE_NULL;
@@ -347,7 +349,7 @@ int qse_strxtoipad6 (const qse_char_t* src, qse_size_t len, qse_ipad6_t* ipad)
 
 	src_end = src + len;
 
-	qse_memset (&tmp, 0, QSE_SIZEOF(tmp));
+	QSE_MEMSET (&tmp, 0, QSE_SIZEOF(tmp));
 	tp = &tmp.value[0];
 	endp = &tmp.value[QSE_COUNTOF(tmp.value)];
 	colonp = QSE_NULL;
@@ -472,7 +474,7 @@ qse_size_t qse_ipad6tostrx (
 	 *	Copy the input (bytewise) array into a wordwise array.
 	 *	Find the longest run of 0x00's in src[] for :: shorthanding.
 	 */
-	qse_memset (words, 0, QSE_SIZEOF(words));
+	QSE_MEMSET (words, 0, QSE_SIZEOF(words));
 	for (i = 0; i < QSE_SIZEOF(ipad->value); i++)
 		words[i / 2] |= (ipad->value[i] << ((1 - (i % 2)) << 3));
 	best.base = -1;
@@ -529,7 +531,7 @@ qse_size_t qse_ipad6tostrx (
 		    (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) 
 		{
 			qse_ipad4_t ipad4;
-			qse_memcpy (&ipad4.value, ipad->value+12, QSE_SIZEOF(ipad4.value));
+			QSE_MEMCPY (&ipad4.value, ipad->value+12, QSE_SIZEOF(ipad4.value));
 			tp += qse_ipad4tostrx (&ipad4, tp, QSE_SIZEOF(tmp) - (tp - tmp));
 			break;
 		}
@@ -547,6 +549,7 @@ qse_size_t qse_ipad6tostrx (
 #undef IP6ADDR_NWORDS
 }
 
+#if 0
 int qse_strtoipad (const qse_char_t* str, qse_ipad_t* ipad)
 {
 	if (qse_strtoipad4 (str, &ipad->u.ip4) <= -1)
diff --git a/qse/lib/cmn/pio.c b/qse/lib/cmn/pio.c
index d27eadf0..ffd7e2b6 100644
--- a/qse/lib/cmn/pio.c
+++ b/qse/lib/cmn/pio.c
@@ -1734,7 +1734,12 @@ void qse_pio_fini (qse_pio_t* pio)
 	qse_pio_wait (pio);
 }
 
-int qse_pio_getoption (qse_pio_t* pio)
+qse_pio_errnum_t qse_pio_geterrnum (const qse_pio_t* pio)
+{
+	return pio->errnum;
+}
+
+int qse_pio_getoption (const qse_pio_t* pio)
 {
 	return pio->option;
 }
@@ -1744,11 +1749,6 @@ void qse_pio_setoption (qse_pio_t* pio, int opt)
 	pio->option = opt;
 }
 
-qse_pio_errnum_t qse_pio_geterrnum (qse_pio_t* pio)
-{
-	return pio->errnum;
-}
-
 qse_cmgr_t* qse_pio_getcmgr (qse_pio_t* pio, qse_pio_hid_t hid)
 {
 	return pio->pin[hid].tio? 
@@ -1760,12 +1760,12 @@ void qse_pio_setcmgr (qse_pio_t* pio, qse_pio_hid_t hid, qse_cmgr_t* cmgr)
 	if (pio->pin[hid].tio) qse_tio_setcmgr (pio->pin[hid].tio, cmgr);
 }
 
-qse_pio_hnd_t qse_pio_gethandle (qse_pio_t* pio, qse_pio_hid_t hid)
+qse_pio_hnd_t qse_pio_gethandle (const qse_pio_t* pio, qse_pio_hid_t hid)
 {
 	return pio->pin[hid].handle;
 }
 
-qse_ubi_t qse_pio_gethandleasubi (qse_pio_t* pio, qse_pio_hid_t hid)
+qse_ubi_t qse_pio_gethandleasubi (const qse_pio_t* pio, qse_pio_hid_t hid)
 {
 	qse_ubi_t handle;
 
@@ -1782,7 +1782,7 @@ qse_ubi_t qse_pio_gethandleasubi (qse_pio_t* pio, qse_pio_hid_t hid)
 	return handle;
 }
 
-qse_pio_pid_t qse_pio_getchild (qse_pio_t* pio)
+qse_pio_pid_t qse_pio_getchild (const qse_pio_t* pio)
 {
 	return pio->child;
 }
diff --git a/qse/lib/cmn/rbt.c b/qse/lib/cmn/rbt.c
index 41db7de8..d2ba599a 100644
--- a/qse/lib/cmn/rbt.c
+++ b/qse/lib/cmn/rbt.c
@@ -248,7 +248,7 @@ void qse_rbt_fini (rbt_t* rbt)
 	qse_rbt_clear (rbt);
 }
 
-const mancbs_t* qse_rbt_getmancbs (rbt_t* rbt)
+const mancbs_t* qse_rbt_getmancbs (const rbt_t* rbt)
 {
 	return rbt->mancbs;
 }
@@ -259,12 +259,12 @@ void qse_rbt_setmancbs (rbt_t* rbt, const mancbs_t* mancbs)
 	rbt->mancbs = mancbs;
 }
 
-size_t qse_rbt_getsize (rbt_t* rbt)
+size_t qse_rbt_getsize (const rbt_t* rbt)
 {
 	return rbt->size;
 }
 
-pair_t* qse_rbt_search (rbt_t* rbt, const void* kptr, size_t klen)
+pair_t* qse_rbt_search (const rbt_t* rbt, const void* kptr, size_t klen)
 {
 	pair_t* pair = rbt->root;
 
@@ -972,7 +972,7 @@ void qse_rbt_rwalk (rbt_t* rbt, walker_t walker, void* ctx)
 }
 
 int qse_rbt_dflcomp (
-	qse_rbt_t* rbt,
+	const qse_rbt_t* rbt,
 	const void* kptr1, size_t klen1,
 	const void* kptr2, size_t klen2)
 {
diff --git a/qse/lib/cmn/rex.c b/qse/lib/cmn/rex.c
index d577c740..328e3f63 100644
--- a/qse/lib/cmn/rex.c
+++ b/qse/lib/cmn/rex.c
@@ -200,7 +200,7 @@ qse_rex_node_t* qse_rex_yield (qse_rex_t* rex)
 	return code;
 }
 
-int qse_rex_getoption (qse_rex_t* rex)
+int qse_rex_getoption (const qse_rex_t* rex)
 {
 	return rex->option;
 }
@@ -210,12 +210,12 @@ void qse_rex_setoption (qse_rex_t* rex, int opts)
 	rex->option = opts;
 }
 
-qse_rex_errnum_t qse_rex_geterrnum (qse_rex_t* rex)
+qse_rex_errnum_t qse_rex_geterrnum (const qse_rex_t* rex)
 {
 	return rex->errnum;
 }
 
-const qse_char_t* qse_rex_geterrmsg (qse_rex_t* rex)
+const qse_char_t* qse_rex_geterrmsg (const qse_rex_t* rex)
 {
 	static const qse_char_t* errstr[] = 
 	{
diff --git a/qse/lib/cmn/sio.c b/qse/lib/cmn/sio.c
index e0061807..cbd250fc 100644
--- a/qse/lib/cmn/sio.c
+++ b/qse/lib/cmn/sio.c
@@ -31,6 +31,14 @@
 #	include "syscall.h"
 #endif
 
+
+/* internal status codes */
+enum
+{
+	STATUS_UTF8_CONSOLE = (1 << 0)
+};
+
+
 static qse_ssize_t file_input (
 	qse_tio_t* tio, qse_tio_cmd_t cmd, void* buf, qse_size_t size);
 static qse_ssize_t file_output (
@@ -113,14 +121,19 @@ qse_sio_t* qse_sio_openstd (
 	qse_fio_hnd_t hnd;
 
 	if (qse_getstdfiohandle (std, &hnd) <= -1) return QSE_NULL;
+
 	sio = qse_sio_open (mmgr, xtnsize, 
 		(const qse_char_t*)&hnd, flags | QSE_SIO_HANDLE | QSE_SIO_NOCLOSE);
 
 #if defined(_WIN32)
 	if (sio) 
 	{
-		QSE_ASSERT (std >= 0 && std < QSE_TYPE_MAX(int));
-		sio->status = std + 1;
+		DWORD mode;
+		if (GetConsoleMode (sio->u.file.handle, &mode) == TRUE &&
+		    GetConsoleOutputCP() == CP_UTF8)
+		{
+			sio->status |= STATUS_UTF8_CONSOLE;
+		}
 	}
 #endif
 
@@ -190,14 +203,19 @@ int qse_sio_initstd (
 	qse_fio_hnd_t hnd;
 
 	if (qse_getstdfiohandle (std, &hnd) <= -1) return -1;
+
 	n = qse_sio_init (sio, mmgr, 
 		(const qse_char_t*)&hnd, flags | QSE_SIO_HANDLE | QSE_SIO_NOCLOSE);
 
 #if defined(_WIN32)
 	if (n >= 0) 
 	{
-		QSE_ASSERT (std >= 0 && std < QSE_TYPE_MAX(int));
-		sio->status = std + 1;
+		DWORD mode;
+		if (GetConsoleMode (sio->u.file.handle, &mode) == TRUE &&
+		    GetConsoleOutputCP() == CP_UTF8)
+		{
+			sio->status |= STATUS_UTF8_CONSOLE;
+		}
 	}
 #endif
 
@@ -212,6 +230,11 @@ void qse_sio_fini (qse_sio_t* sio)
 	qse_fio_fini (&sio->u.file);
 }
 
+qse_sio_errnum_t qse_sio_geterrnum (const qse_sio_t* sio)
+{
+	return sio->errnum;
+}
+
 qse_cmgr_t* qse_sio_getcmgr (qse_sio_t* sio)
 {
 	return qse_tio_getcmgr (&sio->tio.io);
@@ -222,18 +245,13 @@ void qse_sio_setcmgr (qse_sio_t* sio, qse_cmgr_t* cmgr)
 	qse_tio_setcmgr (&sio->tio.io, cmgr);
 }
 
-qse_sio_errnum_t qse_sio_geterrnum (qse_sio_t* sio)
-{
-	return sio->errnum;
-}
-
-qse_sio_hnd_t qse_sio_gethandle (qse_sio_t* sio)
+qse_sio_hnd_t qse_sio_gethandle (const qse_sio_t* sio)
 {
 	/*return qse_fio_gethandle (&sio->u.file);*/
 	return QSE_FIO_HANDLE(&sio->u.file);
 }
 
-qse_ubi_t qse_sio_gethandleasubi (qse_sio_t* sio)
+qse_ubi_t qse_sio_gethandleasubi (const qse_sio_t* sio)
 {
 	return qse_fio_gethandleasubi (&sio->u.file);
 }
@@ -390,7 +408,7 @@ qse_ssize_t qse_sio_putmbs (qse_sio_t* sio, const qse_mchar_t* str)
 
 #if defined(_WIN32)
 	/* Using WriteConsoleA() didn't help at all.
-	 * so I don't implement any hack here */
+	 * so I don't implement any hacks here */
 #endif
 
 	sio->errnum = QSE_SIO_ENOERR;
@@ -408,7 +426,7 @@ qse_ssize_t qse_sio_putmbsn (
 
 #if defined(_WIN32)
 	/* Using WriteConsoleA() didn't help at all.
-	 * so I don't implement any hack here */
+	 * so I don't implement any hacks here */
 #endif
 
 	sio->errnum = QSE_SIO_ENOERR;
@@ -425,37 +443,31 @@ qse_ssize_t qse_sio_putwcs (qse_sio_t* sio, const qse_wchar_t* str)
 
 #if defined(_WIN32)
 	/* DAMN UGLY: See comment in qse_sio_putwcsn() */
-	if (sio->status)
+	if (sio->status & STATUS_UTF8_CONSOLE)
 	{
-		DWORD mode;
+		DWORD count, left;
+		const qse_wchar_t* cur;
 
-		if (GetConsoleMode (sio->u.file.handle, &mode) == TRUE &&
-		    GetConsoleOutputCP() == CP_UTF8)
+		if (qse_sio_flush (sio) <= -1) return -1; /* can't do buffering */
+
+		for (cur = str, left = qse_wcslen(str); left > 0; cur += count, left -= count)
 		{
-			DWORD count, left;
-			const qse_wchar_t* cur;
-
-			if (qse_sio_flush (sio) <= -1) return -1; /* can't do buffering */
-
-			for (cur = str, left = qse_wcslen(str); left > 0; cur += count, left -= count)
+			if (WriteConsoleW (
+				sio->u.file.handle, cur, left,
+				&count, QSE_NULL) == FALSE) 
 			{
-				if (WriteConsoleW (
-					sio->u.file.handle, cur, left,
-					&count, QSE_NULL) == FALSE) 
-				{
-					sio->errnum = QSE_SIO_ESYSERR;
-					return -1;
-				}
-				if (count == 0) break;
-
-				if (count > left) 
-				{
-					sio->errnum = QSE_SIO_ESYSERR;
-					return -1;
-				}
+				sio->errnum = QSE_SIO_ESYSERR;
+				return -1;
+			}
+			if (count == 0) break;
+
+			if (count > left) 
+			{
+				sio->errnum = QSE_SIO_ESYSERR;
+				return -1;
 			}
-			return cur - str;	
 		}
+		return cur - str;	
 	}
 #endif
 
@@ -484,45 +496,39 @@ qse_ssize_t qse_sio_putwcsn (
 	 *  Note that the multibyte functions qse_sio_putmbs() and
 	 *  qse_sio_putmbsn() doesn't handle this. So you may still suffer.
 	 */
-	if (sio->status)
+	if (sio->status & STATUS_UTF8_CONSOLE)
 	{
-		DWORD mode;
+		DWORD count, left;
+		const qse_wchar_t* cur;
 
-		if (GetConsoleMode (sio->u.file.handle, &mode) == TRUE &&
-		    GetConsoleOutputCP() == CP_UTF8)
+		if (qse_sio_flush (sio) <= -1) return -1; /* can't do buffering */
+
+		for (cur = str, left = size; left > 0; cur += count, left -= count)
 		{
-			DWORD count, left;
-			const qse_wchar_t* cur;
-	
-			if (qse_sio_flush (sio) <= -1) return -1; /* can't do buffering */
-
-			for (cur = str, left = size; left > 0; cur += count, left -= count)
+			if (WriteConsoleW (
+				sio->u.file.handle, cur, left, 
+				&count, QSE_NULL) == FALSE) 
 			{
-				if (WriteConsoleW (
-					sio->u.file.handle, cur, left, 
-					&count, QSE_NULL) == FALSE) 
-				{
-					sio->errnum = QSE_SIO_ESYSERR;
-					return -1;
-				}
-				if (count == 0) break;
-
-				/* Note:
-				 * WriteConsoleW() in unicosw.dll on win 9x/me returns
-				 * the number of bytes via 'count'. If a double byte 
-				 * string is given, 'count' can be greater than 'left'.
-				 * this case is a miserable failure. however, i don't
-				 * think there is CP_UTF8 codepage for console on win9x/me.
-				 * so let me make this function fail if that ever happens.
-				 */
-				if (count > left) 
-				{
-					sio->errnum = QSE_SIO_ESYSERR;
-					return -1;
-				}
+				sio->errnum = QSE_SIO_ESYSERR;
+				return -1;
+			}
+			if (count == 0) break;
+
+			/* Note:
+			 * WriteConsoleW() in unicosw.dll on win 9x/me returns
+			 * the number of bytes via 'count'. If a double byte 
+			 * string is given, 'count' can be greater than 'left'.
+			 * this case is a miserable failure. however, i don't
+			 * think there is CP_UTF8 codepage for console on win9x/me.
+			 * so let me make this function fail if that ever happens.
+			 */
+			if (count > left) 
+			{
+				sio->errnum = QSE_SIO_ESYSERR;
+				return -1;
 			}
-			return cur - str;
 		}
+		return cur - str;
 	}	
 
 #endif
diff --git a/qse/lib/cmn/tio.c b/qse/lib/cmn/tio.c
index 416eacad..65ffde4a 100644
--- a/qse/lib/cmn/tio.c
+++ b/qse/lib/cmn/tio.c
@@ -87,7 +87,7 @@ int qse_tio_fini (qse_tio_t* tio)
 	return ret;
 }
 
-qse_tio_errnum_t qse_tio_geterrnum (qse_tio_t* tio)
+qse_tio_errnum_t qse_tio_geterrnum (const qse_tio_t* tio)
 {
 	return tio->errnum;
 }
diff --git a/qse/lib/sed/Sed.cpp b/qse/lib/sed/Sed.cpp
index 0535787f..42ca2ce5 100644
--- a/qse/lib/sed/Sed.cpp
+++ b/qse/lib/sed/Sed.cpp
@@ -239,7 +239,7 @@ const Sed::char_t* Sed::getErrorString (errnum_t num) const
 	return dflerrstr (sed, num);
 }
 
-const Sed::char_t* Sed::xerrstr (sed_t* s, errnum_t num)
+const Sed::char_t* Sed::xerrstr (const sed_t* s, errnum_t num)
 {
 	Sed* sed = *(Sed**)QSE_XTN(s);
 	try
diff --git a/qse/lib/sed/err.c b/qse/lib/sed/err.c
index cbcb1587..a2278263 100644
--- a/qse/lib/sed/err.c
+++ b/qse/lib/sed/err.c
@@ -65,7 +65,7 @@ const qse_char_t* qse_sed_dflerrstr (qse_sed_t* sed, qse_sed_errnum_t errnum)
 		errstr[errnum]: QSE_T("unknown error");
 }
 
-qse_sed_errstr_t qse_sed_geterrstr (qse_sed_t* sed)
+qse_sed_errstr_t qse_sed_geterrstr (const qse_sed_t* sed)
 {
 	return sed->errstr;
 }
@@ -75,24 +75,24 @@ void qse_sed_seterrstr (qse_sed_t* sed, qse_sed_errstr_t errstr)
 	sed->errstr = errstr;
 }
 
-qse_sed_errnum_t qse_sed_geterrnum (qse_sed_t* sed)
+qse_sed_errnum_t qse_sed_geterrnum (const qse_sed_t* sed)
 {
 	return sed->errnum;
 }
 
-const qse_sed_loc_t* qse_sed_geterrloc (qse_sed_t* sed)
+const qse_sed_loc_t* qse_sed_geterrloc (const qse_sed_t* sed)
 {
 	return &sed->errloc;
 }
 
-const qse_char_t* qse_sed_geterrmsg (qse_sed_t* sed)
+const qse_char_t* qse_sed_geterrmsg (const qse_sed_t* sed)
 {
 	return (sed->errmsg[0] == QSE_T('\0'))?
 		qse_sed_geterrstr(sed)(sed,sed->errnum): sed->errmsg;
 }
 
 void qse_sed_geterror (
-	qse_sed_t* sed, qse_sed_errnum_t* errnum, 
+	const qse_sed_t* sed, qse_sed_errnum_t* errnum, 
 	const qse_char_t** errmsg, qse_sed_loc_t* errloc)
 {
 	if (errnum != QSE_NULL) *errnum = sed->errnum;
diff --git a/qse/lib/sed/sed.c b/qse/lib/sed/sed.c
index ddcec936..b18d1324 100644
--- a/qse/lib/sed/sed.c
+++ b/qse/lib/sed/sed.c
@@ -137,13 +137,13 @@ void qse_sed_setoption (qse_sed_t* sed, int option)
 	sed->option = option;
 }
 
-int qse_sed_getoption (qse_sed_t* sed)
+int qse_sed_getoption (const qse_sed_t* sed)
 {
 	return sed->option;
 }
 
 #if defined(USE_REX)
-qse_size_t qse_sed_getmaxdepth (qse_sed_t* sed, qse_sed_depth_t id)
+qse_size_t qse_sed_getmaxdepth (const qse_sed_t* sed, qse_sed_depth_t id)
 {
 	return (id & QSE_SED_DEPTH_REX_BUILD)? sed->depth.rex.build:
 	       (id & QSE_SED_DEPTH_REX_MATCH)? sed->depth.rex.match: 0;
diff --git a/qse/lib/sed/sed.h b/qse/lib/sed/sed.h
index 80a57155..0e74d5f5 100644
--- a/qse/lib/sed/sed.h
+++ b/qse/lib/sed/sed.h
@@ -243,8 +243,8 @@ const qse_char_t* qse_sed_dflerrstr (
  * The qse_sed_getmaxdepth() gets the maximum processing depth.
  */
 qse_size_t qse_sed_getmaxdepth (
-	qse_sed_t*      sed, /**< stream editor */
-	qse_sed_depth_t id   /**< one of qse_sed_depth_t values */
+	const qse_sed_t* sed, /**< stream editor */
+	qse_sed_depth_t  id   /**< one of qse_sed_depth_t values */
 );
 
 /**
diff --git a/qse/lib/sed/std.c b/qse/lib/sed/std.c
index a9ff58ee..55384c09 100644
--- a/qse/lib/sed/std.c
+++ b/qse/lib/sed/std.c
@@ -208,6 +208,10 @@ static void close_main_stream (
 			 * i close this in qse_awk_execstd()
 			 */
 			break;
+
+		default:
+			/* do nothing */
+			break;
 	}
 
 }
@@ -827,7 +831,7 @@ int qse_sed_compstdstr (qse_sed_t* sed, const qse_char_t* script)
 	qse_sed_iostd_t in[2];
 
 	in[0].type = QSE_SED_IOSTD_STR;
-	in[0].u.str.ptr = script;
+	in[0].u.str.ptr = (qse_char_t*)script;
 	in[0].u.str.len = qse_strlen(script);
 	in[1].type = QSE_SED_IOSTD_NULL;