diff --git a/qse/doc/page/awk-lang.md b/qse/doc/page/awk-lang.md
index 71ede6b0..c838e646 100644
--- a/qse/doc/page/awk-lang.md
+++ b/qse/doc/page/awk-lang.md
@@ -232,6 +232,9 @@ sequences for a double-quoted string are all supported in a regular expression.
 
 TBD.
 
+Octal character notation is not supported in a regular expression literal
+since it conflicts with the backreference notation.
+
 ### Note ###
 
 QSEAWK forms a token with the lognest valid sequences.
diff --git a/qse/include/qse/awk/awk.h b/qse/include/qse/awk/awk.h
index ac5fad32..62d143ff 100644
--- a/qse/include/qse/awk/awk.h
+++ b/qse/include/qse/awk/awk.h
@@ -1243,7 +1243,8 @@ enum qse_awk_errnum_t
 	QSE_AWK_EOFMTCHR,      /**< invalid character in OFMT */
 
 	/* regular expression error */
-	QSE_AWK_EREXNOCOMP,    /**< no regular expression compiled */
+	QSE_AWK_EREXBL,        /**< failed to build regular expression */
+	QSE_AWK_EREXMA,        /**< failed to match regular expression */
 	QSE_AWK_EREXRECUR,     /**< recursion too deep */
 	QSE_AWK_EREXRPAREN,    /**< a right parenthesis is expected */
 	QSE_AWK_EREXRBRACK,    /**< a right bracket is expected */
diff --git a/qse/include/qse/cmn/tre.h b/qse/include/qse/cmn/tre.h
index 57d527cf..a14f7a3a 100644
--- a/qse/include/qse/cmn/tre.h
+++ b/qse/include/qse/cmn/tre.h
@@ -79,12 +79,17 @@ enum qse_tre_cflag_t
 	QSE_TRE_RIGHTASSOC  = (1 << 5),
 	QSE_TRE_UNGREEDY    = (1 << 6),
 
+	/* Disable {n,m} occrrence specifier 
+	 * in the QSE_TRE_EXTENDED mode.
+	 * it doesn't affect the BRE's \{\}. */
+	QSE_TRE_NOBOUND     = (1 << 7),
+
 	/* Enable non-standard extensions:
 	 *  - Enable (?:text) for no submatch backreference.
 	 *  - Enable perl-like (?...) extensions like (?i) 
 	 *    if QSE_TRE_EXTENDED is also set.
 	 */
-	QSE_TRE_NONSTDEXT   = (1 << 7) 
+	QSE_TRE_NONSTDEXT   = (1 << 8) 
 };
 
 enum qse_tre_eflag_t
diff --git a/qse/lib/awk/awk.h b/qse/lib/awk/awk.h
index ff024d3e..5998a291 100644
--- a/qse/lib/awk/awk.h
+++ b/qse/lib/awk/awk.h
@@ -352,10 +352,4 @@ struct qse_awk_mod_data_t
 	qse_awk_mod_t mod;
 };
 
-#define QSE_AWK_FREEREX(awk,code) qse_freerex((awk)->mmgr,code)
-#define QSE_AWK_BUILDREX(awk,ptn,len,errnum) \
-	qse_awk_buildrex(awk,ptn,len,errnum)
-#define QSE_AWK_MATCHREX(awk,code,option,str,substr,match,errnum) \
-	qse_awk_matchrex(awk,code,option,str,substr,match,errnum)
-
 #endif
diff --git a/qse/lib/awk/err.c b/qse/lib/awk/err.c
index 11d0063c..a188527c 100644
--- a/qse/lib/awk/err.c
+++ b/qse/lib/awk/err.c
@@ -141,7 +141,8 @@ const qse_char_t* qse_awk_dflerrstr (const qse_awk_t* awk, qse_awk_errnum_t errn
 		QSE_T("invalid character in CONVFMT"),
 		QSE_T("invalid character in OFMT"),
 
-		QSE_T("no regular expression compiled"),
+		QSE_T("failed to build regular expression"),
+		QSE_T("failed to match regular expression"),
 		QSE_T("recursion too deep in regular expression"),
 		QSE_T("right parenthesis expected in regular expression"),
 		QSE_T("right bracket expected in regular expression"),
diff --git a/qse/lib/awk/fnc.c b/qse/lib/awk/fnc.c
index 11e6cf0c..f86f6dc3 100644
--- a/qse/lib/awk/fnc.c
+++ b/qse/lib/awk/fnc.c
@@ -738,7 +738,7 @@ static int fnc_split (qse_awk_rtx_t* run, const qse_awk_fnc_info_t* fi)
 
 		if (fs.len > 1) 
 		{
-			fs_rex = QSE_AWK_BUILDREX (
+			fs_rex = qse_awk_buildrex (
 				run->awk, fs.ptr, fs.len, &errnum);
 			if (fs_rex == QSE_NULL)
 			{
@@ -816,7 +816,7 @@ static int fnc_split (qse_awk_rtx_t* run, const qse_awk_fnc_info_t* fi)
 
 	if (str_free) QSE_AWK_FREE (run->awk, str_free);
 	if (fs_free) QSE_AWK_FREE (run->awk, fs_free);
-	if (fs_rex_free) QSE_AWK_FREEREX (run->awk, fs_rex_free);
+	if (fs_rex_free) qse_awk_freerex (run->awk, fs_rex_free);
 
 	/*nflds--;*/
 
@@ -829,7 +829,7 @@ static int fnc_split (qse_awk_rtx_t* run, const qse_awk_fnc_info_t* fi)
 oops:
 	if (str_free) QSE_AWK_FREE (run->awk, str_free);
 	if (fs_free) QSE_AWK_FREE (run->awk, fs_free);
-	if (fs_rex_free) QSE_AWK_FREEREX (run->awk, fs_rex_free);
+	if (fs_rex_free) qse_awk_freerex (run->awk, fs_rex_free);
 	return -1;
 }
 
@@ -1033,7 +1033,7 @@ static int __substitute (qse_awk_rtx_t* run, qse_long_t max_count)
 	{
 		qse_awk_errnum_t errnum;
 
-		rex = QSE_AWK_BUILDREX (
+		rex = qse_awk_buildrex (
 			run->awk, s0.ptr, s0.len, &errnum);
 		if (rex == QSE_NULL)
 		{
@@ -1064,7 +1064,7 @@ static int __substitute (qse_awk_rtx_t* run, qse_long_t max_count)
 
 		if (max_count == 0 || sub_count < max_count)
 		{
-			n = QSE_AWK_MATCHREX (
+			n = qse_awk_matchrex (
 				run->awk, rex, opt, &s2, &cur, &mat, &errnum
 			);
 		}
@@ -1153,7 +1153,7 @@ static int __substitute (qse_awk_rtx_t* run, qse_long_t max_count)
 
 	if (rex_free)
 	{
-		QSE_AWK_FREEREX (run->awk, rex_free); 
+		qse_awk_freerex (run->awk, rex_free); 
 		rex_free = QSE_NULL;
 	}
 
@@ -1199,7 +1199,7 @@ static int __substitute (qse_awk_rtx_t* run, qse_long_t max_count)
 	return 0;
 
 oops:
-	if (rex_free) QSE_AWK_FREEREX (run->awk, rex_free); 
+	if (rex_free) qse_awk_freerex (run->awk, rex_free); 
 	if (new_inited) qse_str_fini (&new);
 	if (s2_free) QSE_AWK_FREE (run->awk, s2_free);
 	if (s1_free) QSE_AWK_FREE (run->awk, s1_free);
@@ -1295,7 +1295,7 @@ static int fnc_match (qse_awk_rtx_t* rtx, const qse_awk_fnc_info_t* fi)
 			}
 		}
 
-		rex = QSE_AWK_BUILDREX (rtx->awk, str1, len1, &errnum);
+		rex = qse_awk_buildrex (rtx->awk, str1, len1, &errnum);
 		if (rex == QSE_NULL)
 		{
 			if (a0->type != QSE_AWK_VAL_STR) 
@@ -1318,7 +1318,7 @@ static int fnc_match (qse_awk_rtx_t* rtx, const qse_awk_fnc_info_t* fi)
 		/*TODO: must use str0,len0?*/
 		tmp.ptr = str0 + start - 1;
 		tmp.len = len0 - start + 1;
-		n = QSE_AWK_MATCHREX (
+		n = qse_awk_matchrex (
 			rtx->awk, rex, 
 			(rtx->gbl.ignorecase? QSE_REX_IGNORECASE: 0),
 			&tmp, &tmp, &mat, &errnum
@@ -1326,7 +1326,7 @@ static int fnc_match (qse_awk_rtx_t* rtx, const qse_awk_fnc_info_t* fi)
 	}
 
 	if (a0->type != QSE_AWK_VAL_STR) QSE_AWK_FREE (rtx->awk, str0);
-	if (a1->type != QSE_AWK_VAL_REX) QSE_AWK_FREEREX (rtx->awk, rex);
+	if (a1->type != QSE_AWK_VAL_REX) qse_awk_freerex (rtx->awk, rex);
 
 	if (n <= -1) 
 	{
diff --git a/qse/lib/awk/misc.c b/qse/lib/awk/misc.c
index a313e070..0758f9f3 100644
--- a/qse/lib/awk/misc.c
+++ b/qse/lib/awk/misc.c
@@ -20,6 +20,14 @@
 
 #include "awk.h"
 
+#define USE_REX 
+
+#if defined(USE_REX)
+#	include <qse/cmn/rex.h>
+#else
+#	include <qse/cmn/tre.h>
+#endif
+
 void* qse_awk_allocmem (qse_awk_t* awk, qse_size_t size)
 {
 	void* ptr = QSE_AWK_ALLOC (awk, size);
@@ -883,7 +891,7 @@ qse_char_t* qse_awk_rtx_strxntokbyrex (
 
 	while (cursub.len > 0)
 	{
-		n = QSE_AWK_MATCHREX (
+		n = qse_awk_matchrex (
 			rtx->awk, rex, 
 			((rtx->gbl.ignorecase)? QSE_REX_IGNORECASE: 0),
 			&s, &cursub, &match, errnum);
@@ -1061,51 +1069,162 @@ qse_char_t* qse_awk_rtx_strxnfld (
 	return QSE_NULL;
 }
 
-#define QSE_AWK_REXERRTOERR(err) \
-	((err == QSE_REX_ENOERR)?      QSE_AWK_ENOERR: \
-	 (err == QSE_REX_ENOMEM)?      QSE_AWK_ENOMEM: \
-	 (err == QSE_REX_ENOCOMP)?     QSE_AWK_EREXNOCOMP: \
-	 (err == QSE_REX_ERECUR)?      QSE_AWK_EREXRECUR: \
-	 (err == QSE_REX_ERPAREN)?     QSE_AWK_EREXRPAREN: \
-	 (err == QSE_REX_ERBRACK)?     QSE_AWK_EREXRBRACK: \
-	 (err == QSE_REX_ERBRACE)?     QSE_AWK_EREXRBRACE: \
-	 (err == QSE_REX_ECOLON)?      QSE_AWK_EREXCOLON: \
-	 (err == QSE_REX_ECRANGE)?     QSE_AWK_EREXCRANGE: \
-	 (err == QSE_REX_ECCLASS)?     QSE_AWK_EREXCCLASS: \
-	 (err == QSE_REX_EBOUND)?      QSE_AWK_EREXBOUND: \
-	 (err == QSE_REX_ESPCAWP)?     QSE_AWK_EREXSPCAWP: \
-	 (err == QSE_REX_EPREEND)?     QSE_AWK_EREXPREEND: \
-	                               QSE_AWK_EINTERN)
+static QSE_INLINE int rexerr_to_errnum (int err)
+{
+	switch (err)
+	{
+		case QSE_REX_ENOERR:   return QSE_AWK_ENOERR;
+		case QSE_REX_ENOMEM:   return QSE_AWK_ENOMEM;
+	 	case QSE_REX_ENOCOMP:  return QSE_AWK_EREXBL;
+	 	case QSE_REX_ERECUR:   return QSE_AWK_EREXRECUR;
+	 	case QSE_REX_ERPAREN:  return QSE_AWK_EREXRPAREN;
+	 	case QSE_REX_ERBRACK:  return QSE_AWK_EREXRBRACK;
+	 	case QSE_REX_ERBRACE:  return QSE_AWK_EREXRBRACE;
+	 	case QSE_REX_ECOLON:   return QSE_AWK_EREXCOLON;
+	 	case QSE_REX_ECRANGE:  return QSE_AWK_EREXCRANGE;
+	 	case QSE_REX_ECCLASS:  return QSE_AWK_EREXCCLASS;
+	 	case QSE_REX_EBOUND:   return QSE_AWK_EREXBOUND;
+	 	case QSE_REX_ESPCAWP:  return QSE_AWK_EREXSPCAWP;
+	 	case QSE_REX_EPREEND:  return QSE_AWK_EREXPREEND;
+		default:               return QSE_AWK_EINTERN;
+	}
+}
 
 void* qse_awk_buildrex (
 	qse_awk_t* awk, const qse_char_t* ptn, 
 	qse_size_t len, qse_awk_errnum_t* errnum)
 {
+#if defined(USE_REX)
 	qse_rex_errnum_t err;
 	void* p;
 
 	p = qse_buildrex (
 		awk->mmgr, awk->opt.depth.s.rex_build,
-		((awk->opt.trait&QSE_AWK_REXBOUND)? 0: QSE_REX_NOBOUND),
+		((awk->opt.trait & QSE_AWK_REXBOUND)? 0: QSE_REX_NOBOUND),
 		ptn, len, &err
 	);
-	if (p == QSE_NULL) *errnum = QSE_AWK_REXERRTOERR(err);
+	if (p == QSE_NULL) *errnum = rexerr_to_errnum(err);
 	return p;
+#else
+	qse_tre_t* tre;
+	int opt = QSE_TRE_EXTENDED;
+
+	tre = qse_tre_open (awk->mmgr, 0);
+	if (tre == QSE_NULL)
+	{
+		*errnum = QSE_AWK_ENOMEM;
+		return QSE_NULL;
+	}
+
+	/* ignorecase is a compile option for TRE */
+#if 0 /* TODO */
+	if (ignorecase) opt |= QSE_TRE_IGNORECASE; 
+#endif
+	if (!(awk->opt.trait & QSE_AWK_REXBOUND)) opt |= QSE_TRE_NOBOUND;
+
+	if (qse_tre_compx (tre, ptn, len, QSE_NULL, opt) <= -1)
+	{
+#if 0 /* TODO */
+
+		if (QSE_TRE_ERRNUM(tre) == QSE_TRE_ENOMEM) *errnum = QSE_AWK_ENOMEM;
+		else
+			SETERR1 (awk, QSE_AWK_EREXBL, str->ptr, str->len, loc);
+#endif
+		*errnum = (QSE_TRE_ERRNUM(tre) == QSE_TRE_ENOMEM)? 
+			QSE_AWK_ENOMEM: QSE_AWK_EREXBL;
+		qse_tre_close (tre);
+		return QSE_NULL;
+	}
+
+	return tre;
+#endif
 }
 
+#if !defined(USE_REX)
+
+static int matchtre (
+	qse_awk_t* awk, qse_tre_t* tre, int opt, 
+	const qse_cstr_t* str, qse_cstr_t* mat, 
+	qse_cstr_t submat[9], qse_awk_errnum_t* errnum)
+{
+	int n;
+	qse_tre_match_t match[10] = { { 0, 0 }, };
+
+	n = qse_tre_execx (tre, str->ptr, str->len, match, QSE_COUNTOF(match), opt);
+	if (n <= -1)
+	{
+		if (QSE_TRE_ERRNUM(tre) == QSE_TRE_ENOMATCH) return 0;
+
+#if 0 /* TODO: */
+		*errnum = (QSE_TRE_ERRNUM(tre) == QSE_TRE_ENOMEM)? 
+			QSE_AWK_ENOMEM: QSE_AWK_EREXMA;
+		SETERR0 (sed, errnum, loc);
+#endif
+		*errnum = (QSE_TRE_ERRNUM(tre) == QSE_TRE_ENOMEM)? 
+			QSE_AWK_ENOMEM: QSE_AWK_EREXMA;
+		return -1;	
+	}
+
+	QSE_ASSERT (match[0].rm_so != -1);
+	if (mat)
+	{
+		mat->ptr = &str->ptr[match[0].rm_so];
+		mat->len = match[0].rm_eo - match[0].rm_so;
+	}
+
+	if (submat)
+	{
+		int i;
+
+		/* you must intialize submat before you pass into this 
+		 * function because it can abort filling */
+		for (i = 1; i < QSE_COUNTOF(match); i++)
+		{
+			if (match[i].rm_so != -1) 
+			{
+				submat[i-1].ptr = &str->ptr[match[i].rm_so];
+				submat[i-1].len = match[i].rm_eo - match[i].rm_so;
+			}
+		}
+	}
+	return 1;
+}
+#endif
+
 int qse_awk_matchrex (
 	qse_awk_t* awk, void* code, int option,
 	const qse_cstr_t* str, const qse_cstr_t* substr,
 	qse_cstr_t* match, qse_awk_errnum_t* errnum)
 {
+#if defined(USE_REX)
 	int x;
 	qse_rex_errnum_t err;
 
 	x = qse_matchrex (
 		awk->mmgr, awk->opt.depth.s.rex_match,
 		code, option, str, substr, match, &err);
-	if (x <= -1) *errnum = QSE_AWK_REXERRTOERR(err);
+	if (x <= -1) *errnum = rexerr_to_errnum(err);
 	return x;
+#else
+	int x;
+	int opt = QSE_TRE_BACKTRACKING; /* TODO: option... QSE_TRE_BACKTRACKING ??? */
+
+	x = matchtre (
+		awk, code,
+		((str->ptr == substr->ptr)? opt: (opt | QSE_TRE_NOTBOL)),
+		substr, match, QSE_NULL, errnum
+	);
+	return x;
+#endif
+}
+
+void qse_awk_freerex (qse_awk_t* awk, void* code)
+{
+#if defined(USE_REX)
+	qse_freerex((awk)->mmgr,code);
+#else
+	qse_tre_close (code);
+#endif
 }
 
 void* qse_awk_rtx_allocmem (qse_awk_rtx_t* rtx, qse_size_t size)
diff --git a/qse/lib/awk/misc.h b/qse/lib/awk/misc.h
index 04f8a54b..49a78563 100644
--- a/qse/lib/awk/misc.h
+++ b/qse/lib/awk/misc.h
@@ -76,6 +76,8 @@ int qse_awk_matchrex (
 	qse_cstr_t* match, qse_awk_errnum_t* errnum
 );
 
+void qse_awk_freerex (qse_awk_t* awk, void* code);
+
 int qse_awk_sprintflt (
 	qse_awk_t*  awk,
 	qse_char_t* buf,
diff --git a/qse/lib/awk/parse.c b/qse/lib/awk/parse.c
index 268ac6eb..f717cb3f 100644
--- a/qse/lib/awk/parse.c
+++ b/qse/lib/awk/parse.c
@@ -4340,9 +4340,8 @@ static qse_awk_nde_t* parse_primary_rex  (qse_awk_t* awk, const qse_awk_loc_t* x
 	nde->str.ptr = qse_awk_cstrdup (awk, QSE_STR_CSTR(awk->tok.name));
 	if (nde->str.ptr == QSE_NULL) goto oops;
 
-	nde->code = QSE_AWK_BUILDREX (awk,
-		QSE_STR_PTR(awk->tok.name), QSE_STR_LEN(awk->tok.name), 
-		&errnum);
+	nde->code = qse_awk_buildrex (
+		awk, QSE_STR_PTR(awk->tok.name), QSE_STR_LEN(awk->tok.name), &errnum);
 	if (nde->code == QSE_NULL)
 	{
 		SETERR_LOC (awk, errnum, xloc);
@@ -4355,7 +4354,7 @@ static qse_awk_nde_t* parse_primary_rex  (qse_awk_t* awk, const qse_awk_loc_t* x
 
 oops:
 	QSE_ASSERT (nde != QSE_NULL);
-	if (nde->code) QSE_AWK_FREEREX (awk, nde->code);
+	if (nde->code) qse_awk_freerex (awk, nde->code);
 	if (nde->str.ptr) QSE_AWK_FREE (awk, nde->str.ptr);
 	QSE_AWK_FREE (awk, nde);
 	return QSE_NULL;
@@ -5609,8 +5608,10 @@ static int get_string (
 			else if (c == QSE_T('b')) c = QSE_T('\b');
 			else if (c == QSE_T('v')) c = QSE_T('\v');
 			else if (c == QSE_T('a')) c = QSE_T('\a');
-			else if (c >= QSE_T('0') && c <= QSE_T('7')) 
+			else if (c >= QSE_T('0') && c <= QSE_T('7') && end_char != QSE_T('/')) 
 			{
+				/* i don't support the octal notation for a regular expression.
+				 * it conflicts with the backreference notation between \1 and \7 inclusive. */
 				escaped = 3;
 				digit_count = 1;
 				c_acc = c - QSE_T('0');
diff --git a/qse/lib/awk/rio.c b/qse/lib/awk/rio.c
index bf0049a9..fd074e8e 100644
--- a/qse/lib/awk/rio.c
+++ b/qse/lib/awk/rio.c
@@ -225,7 +225,7 @@ static QSE_INLINE int match_long_rs (
 
 	QSE_ASSERT (run->gbl.rs != QSE_NULL);
 
-	ret = QSE_AWK_MATCHREX (
+	ret = qse_awk_matchrex (
 		run->awk, run->gbl.rs,
 		((run->gbl.ignorecase)? QSE_REX_IGNORECASE: 0),
 		QSE_STR_CSTR(buf), QSE_STR_CSTR(buf),
diff --git a/qse/lib/awk/run.c b/qse/lib/awk/run.c
index cff58f38..d015b6fe 100644
--- a/qse/lib/awk/run.c
+++ b/qse/lib/awk/run.c
@@ -422,7 +422,7 @@ static int set_global (
 				void* rex;
 				qse_awk_errnum_t errnum;
 
-				rex = QSE_AWK_BUILDREX (
+				rex = qse_awk_buildrex (
 					rtx->awk, fs_ptr, fs_len, &errnum);
 				if (rex == QSE_NULL)
 				{
@@ -433,7 +433,7 @@ static int set_global (
 				}
 
 				if (rtx->gbl.fs != QSE_NULL)
-					QSE_AWK_FREEREX (rtx->awk, rtx->gbl.fs);
+					qse_awk_freerex (rtx->awk, rtx->gbl.fs);
 				
 				rtx->gbl.fs = rex;
 			}
@@ -571,7 +571,7 @@ static int set_global (
 
 			if (rtx->gbl.rs)
 			{
-				QSE_AWK_FREEREX (rtx->awk, rtx->gbl.rs);
+				qse_awk_freerex (rtx->awk, rtx->gbl.rs);
 				rtx->gbl.rs = QSE_NULL;
 			}
 
@@ -581,7 +581,7 @@ static int set_global (
 				qse_awk_errnum_t errnum;
 				
 				/* compile the regular expression */
-				rex = QSE_AWK_BUILDREX (
+				rex = qse_awk_buildrex (
 					rtx->awk, rss.ptr, rss.len, &errnum);
 				if (rex == QSE_NULL)
 				{
@@ -1007,12 +1007,12 @@ static void fini_rtx (qse_awk_rtx_t* rtx, int fini_globals)
 
 	if (rtx->gbl.rs)
 	{
-		QSE_AWK_FREEREX (rtx->awk, rtx->gbl.rs);
+		qse_awk_freerex (rtx->awk, rtx->gbl.rs);
 		rtx->gbl.rs = QSE_NULL;
 	}
 	if (rtx->gbl.fs)
 	{
-		QSE_AWK_FREEREX (rtx->awk, rtx->gbl.fs);
+		qse_awk_freerex (rtx->awk, rtx->gbl.fs);
 		rtx->gbl.fs = QSE_NULL;
 	}
 
@@ -3173,7 +3173,7 @@ static qse_awk_val_t* eval_expression (qse_awk_rtx_t* rtx, qse_awk_nde_t* nde)
 			vs.len = ((qse_awk_val_str_t*)rtx->inrec.d0)->val.len;
 		}	
 
-		n = QSE_AWK_MATCHREX (
+		n = qse_awk_matchrex (
 			((qse_awk_rtx_t*)rtx)->awk, 
 			((qse_awk_val_rex_t*)v)->code,
 			opt, &vs, &vs, QSE_NULL, &errnum
@@ -4852,7 +4852,7 @@ static qse_awk_val_t* eval_binop_match0 (
 	}
 	else if (right->type == QSE_AWK_VAL_STR)
 	{
-		rex_code = QSE_AWK_BUILDREX ( 
+		rex_code = qse_awk_buildrex ( 
 			rtx->awk,
 			((qse_awk_val_str_t*)right)->val.ptr,
 			((qse_awk_val_str_t*)right)->val.len, &errnum);
@@ -4869,7 +4869,7 @@ static qse_awk_val_t* eval_binop_match0 (
 		out.type = QSE_AWK_RTX_VALTOSTR_CPLDUP;
 		if (qse_awk_rtx_valtostr (rtx, right, &out) <= -1) return QSE_NULL;
 
-		rex_code = QSE_AWK_BUILDREX (
+		rex_code = qse_awk_buildrex (
 			rtx->awk, out.u.cpldup.ptr, out.u.cpldup.len, &errnum);
 		if (rex_code == QSE_NULL)
 		{
@@ -4883,7 +4883,7 @@ static qse_awk_val_t* eval_binop_match0 (
 
 	if (left->type == QSE_AWK_VAL_STR)
 	{
-		n = QSE_AWK_MATCHREX (
+		n = qse_awk_matchrex (
 			rtx->awk, rex_code,
 			((rtx->gbl.ignorecase)? QSE_REX_IGNORECASE: 0),
 			xstr_to_cstr(&((qse_awk_val_str_t*)left)->val),
@@ -4892,7 +4892,7 @@ static qse_awk_val_t* eval_binop_match0 (
 		if (n == -1) 
 		{
 			if (right->type != QSE_AWK_VAL_REX) 
-				QSE_AWK_FREEREX (rtx->awk, rex_code);
+				qse_awk_freerex (rtx->awk, rex_code);
 
 			SETERR_LOC (rtx, errnum, lloc);
 			return QSE_NULL;
@@ -4902,7 +4902,7 @@ static qse_awk_val_t* eval_binop_match0 (
 		if (res == QSE_NULL) 
 		{
 			if (right->type != QSE_AWK_VAL_REX) 
-				QSE_AWK_FREEREX (rtx->awk, rex_code);
+				qse_awk_freerex (rtx->awk, rex_code);
 
 			ADJERR_LOC (rtx, lloc);
 			return QSE_NULL;
@@ -4916,11 +4916,11 @@ static qse_awk_val_t* eval_binop_match0 (
 		if (qse_awk_rtx_valtostr (rtx, left, &out) <= -1)
 		{
 			if (right->type != QSE_AWK_VAL_REX) 
-				QSE_AWK_FREEREX (rtx->awk, rex_code);
+				qse_awk_freerex (rtx->awk, rex_code);
 			return QSE_NULL;
 		}
 
-		n = QSE_AWK_MATCHREX (
+		n = qse_awk_matchrex (
 			rtx->awk, rex_code,
 			((rtx->gbl.ignorecase)? QSE_REX_IGNORECASE: 0),
 			xstr_to_cstr(&out.u.cpldup),
@@ -4931,7 +4931,7 @@ static qse_awk_val_t* eval_binop_match0 (
 		{
 			QSE_AWK_FREE (rtx->awk, out.u.cpldup.ptr);
 			if (right->type != QSE_AWK_VAL_REX) 
-				QSE_AWK_FREEREX (rtx->awk, rex_code);
+				qse_awk_freerex (rtx->awk, rex_code);
 
 			SETERR_LOC (rtx, errnum, lloc);
 			return QSE_NULL;
@@ -4942,7 +4942,7 @@ static qse_awk_val_t* eval_binop_match0 (
 		{
 			QSE_AWK_FREE (rtx->awk, out.u.cpldup.ptr);
 			if (right->type != QSE_AWK_VAL_REX) 
-				QSE_AWK_FREEREX (rtx->awk, rex_code);
+				qse_awk_freerex (rtx->awk, rex_code);
 
 			ADJERR_LOC (rtx, lloc);
 			return QSE_NULL;
@@ -4951,7 +4951,7 @@ static qse_awk_val_t* eval_binop_match0 (
 		QSE_AWK_FREE (rtx->awk, out.u.cpldup.ptr);
 	}
 
-	if (right->type != QSE_AWK_VAL_REX) QSE_AWK_FREEREX (rtx->awk, rex_code);
+	if (right->type != QSE_AWK_VAL_REX) qse_awk_freerex (rtx->awk, rex_code);
 	return res;
 }
 
diff --git a/qse/lib/awk/tree.c b/qse/lib/awk/tree.c
index 8c7493cd..28df3381 100644
--- a/qse/lib/awk/tree.c
+++ b/qse/lib/awk/tree.c
@@ -1305,7 +1305,7 @@ void qse_awk_clrpt (qse_awk_t* awk, qse_awk_nde_t* tree)
 
 			case QSE_AWK_NDE_REX:
 			{
-				QSE_AWK_FREEREX (awk, ((qse_awk_nde_rex_t*)p)->code);
+				qse_awk_freerex (awk, ((qse_awk_nde_rex_t*)p)->code);
 				QSE_AWK_FREE (awk, ((qse_awk_nde_rex_t*)p)->str.ptr);
 				QSE_AWK_FREE (awk, p);
 				break;
diff --git a/qse/lib/awk/val.c b/qse/lib/awk/val.c
index 2d04e689..79fb52eb 100644
--- a/qse/lib/awk/val.c
+++ b/qse/lib/awk/val.c
@@ -832,7 +832,7 @@ void qse_awk_rtx_freeval (
 		
 			/* code is just a pointer to a regular expression stored
 			 * in parse tree nodes. so don't free it.
-			QSE_AWK_FREEREX (rtx->awk, ((qse_awk_val_rex_t*)val)->code);
+			qse_awk_freerex (rtx->awk, ((qse_awk_val_rex_t*)val)->code);
 			 */
 
 			QSE_AWK_FREE (rtx->awk, val);
diff --git a/qse/lib/cmn/tre-compile.c b/qse/lib/cmn/tre-compile.c
index 849ed64b..53dc3f8e 100644
--- a/qse/lib/cmn/tre-compile.c
+++ b/qse/lib/cmn/tre-compile.c
@@ -1690,10 +1690,8 @@ tre_make_trans(qse_mmgr_t* mmgr, tre_pos_and_tags_t *p1, tre_pos_and_tags_t *p2,
 				if (p1->neg_classes != NULL)
 				{
 					for (i = 0; p1->neg_classes[i] != (tre_ctype_t)0; i++);
-					trans->neg_classes =
-					    xmalloc(mmgr,sizeof(*trans->neg_classes) * (i + 1));
-					if (trans->neg_classes == NULL)
-						return REG_ESPACE;
+					trans->neg_classes = xmalloc(mmgr,sizeof(*trans->neg_classes) * (i + 1));
+					if (trans->neg_classes == NULL) return REG_ESPACE;
 					for (i = 0; p1->neg_classes[i] != (tre_ctype_t)0; i++)
 						trans->neg_classes[i] = p1->neg_classes[i];
 					trans->neg_classes[i] = (tre_ctype_t)0;
diff --git a/qse/lib/cmn/tre-match-backtrack.c b/qse/lib/cmn/tre-match-backtrack.c
index ddf55803..37d4367d 100644
--- a/qse/lib/cmn/tre-match-backtrack.c
+++ b/qse/lib/cmn/tre-match-backtrack.c
@@ -400,7 +400,7 @@ retry:
 		/* Go to the next character in the input string. */
 		empty_br_match = 0;
 		trans_i = state;
-		if (trans_i->state && trans_i->assertions & ASSERT_BACKREF)
+		if (trans_i->state && (trans_i->assertions & ASSERT_BACKREF))
 		{
 			/* This is a back reference state.  All transitions leaving from
 			   this state have the same back reference "assertion".  Instead
@@ -593,8 +593,7 @@ backtrack:
 				DPRINT(("	 backtracking\n"));
 				if (stack->item.state->assertions && ASSERT_BACKREF)
 				{
-					DPRINT(("  states_seen[%d] = 0\n",
-					        stack->item.state_id));
+					DPRINT(("  states_seen[%d] = 0\n", stack->item.state_id));
 					states_seen[stack->item.state_id] = 0;
 				}
 
diff --git a/qse/lib/cmn/tre-parse.c b/qse/lib/cmn/tre-parse.c
index dbc3c54d..9ad387db 100644
--- a/qse/lib/cmn/tre-parse.c
+++ b/qse/lib/cmn/tre-parse.c
@@ -1174,14 +1174,16 @@ parse_star:
 					goto parse_star;
 				}
 			}
-			else break;
+			break;
 			/* END QSE */
 
 
 		case CHAR_LBRACE:
 			/* "{" is literal without REG_EXTENDED */
-			if (!(ctx->cflags & REG_EXTENDED))
-				break;
+			if (!(ctx->cflags & REG_EXTENDED)) break;
+			/* QSE */
+			if (ctx->cflags & REG_NOBOUND) break;
+			/* END QSE */
 
 parse_brace:
 			DPRINT(("tre_parse:	bound: '%.*" STRF "'\n",
@@ -1194,6 +1196,7 @@ parse_brace:
 			STACK_PUSHX(stack, int, PARSE_POSTFIX);
 			break;
 		}
+
 		break;
 
 	case PARSE_ATOM:
@@ -1686,7 +1689,10 @@ parse_literal:
 			     || *ctx->re == CHAR_STAR
 			     || (ctx->cflags & REG_EXTENDED
 			         && (*ctx->re == CHAR_PIPE
-			             || *ctx->re == CHAR_LBRACE
+				/* QSE */
+			             /*|| *ctx->re == CHAR_LBRACE*/
+			             || (*ctx->re == CHAR_LBRACE && !(ctx->cflags & REG_NOBOUND))
+				/* END QSE */
 			             || *ctx->re == CHAR_PLUS
 			             || *ctx->re == CHAR_QUESTIONMARK))
 			     /* Test for "\)" in BRE mode. */
diff --git a/qse/lib/cmn/tre.c b/qse/lib/cmn/tre.c
index a0f01519..1e2afdff 100644
--- a/qse/lib/cmn/tre.c
+++ b/qse/lib/cmn/tre.c
@@ -202,7 +202,7 @@ static int tre_match(
 	}
 
 	/* Dispatch to the appropriate matcher. */
-	if (tnfa->have_backrefs || eflags & REG_BACKTRACKING_MATCHER)
+	if (tnfa->have_backrefs || (eflags & REG_BACKTRACKING_MATCHER))
 	{
 		/* The regex has back references, use the backtracking matcher. */
 		if (type == STR_USER)
diff --git a/qse/lib/cmn/tre.h b/qse/lib/cmn/tre.h
index e4155860..8d5bb03b 100644
--- a/qse/lib/cmn/tre.h
+++ b/qse/lib/cmn/tre.h
@@ -208,6 +208,7 @@ typedef qse_cint_t tre_cint_t;
 #define REG_LITERAL     QSE_TRE_LITERAL 
 #define REG_RIGHT_ASSOC QSE_TRE_RIGHTASSOC
 #define REG_UNGREEDY    QSE_TRE_UNGREEDY 
+#define REG_NOBOUND     QSE_TRE_NOBOUND
 #define REG_NONSTDEXT   QSE_TRE_NONSTDEXT
 
 /* POSIX tre_regexec() flags. */
diff --git a/qse/lib/http/httpd-dir.c b/qse/lib/http/httpd-dir.c
index cc3d6aa5..75833301 100644
--- a/qse/lib/http/httpd-dir.c
+++ b/qse/lib/http/httpd-dir.c
@@ -536,6 +536,21 @@ static QSE_INLINE int task_main_getdir (
 		);
 		if (x) 
 		{
+#if 0
+			if (httpd->opt.trait & QSE_HTTPD_LOGACC)
+			{
+				qse_httpd_reqsum_t reqsum;
+
+				acc.remote = remote;
+				acc.qpath = qpath;	
+				acc.status = 200;
+				acc.version =  ...;
+				acc.method =  ...;
+
+				httpd->opt.rcb.logacc (httpd, &reqsum);
+			}
+#endif
+
 			/* arrange to send the actual directory contents */
 			x = entask_directory_segment (httpd, client, x, dir->handle, dir);
 			if (x) return 0;
diff --git a/qse/lib/http/httpd-file.c b/qse/lib/http/httpd-file.c
index 53c0c670..08f4161f 100644
--- a/qse/lib/http/httpd-file.c
+++ b/qse/lib/http/httpd-file.c
@@ -605,7 +605,9 @@ qse_httpd_task_t* qse_httpd_entaskfile (
 
 			task.init = task_init_getfile;
 			task.main = task_main_getfile;
-			break;
+
+			task.ctx = &data;
+			return qse_httpd_entask (httpd, client, pred, &task, xtnsize);
 
 		case QSE_HTTP_PUT:
 			/* note that no partial update is supported for PUT */
@@ -614,7 +616,8 @@ qse_httpd_task_t* qse_httpd_entaskfile (
 			task.init = task_init_putfile;
 			task.main = task_main_putfile;
 			task.fini = task_fini_putfile;
-			break;
+			task.ctx = &data;
+			return qse_httpd_entask (httpd, client, pred, &task, xtnsize);
 
 		case QSE_HTTP_DELETE:
 		{
@@ -637,7 +640,5 @@ qse_httpd_task_t* qse_httpd_entaskfile (
 	}
 
 
-	task.ctx = &data;
-	return qse_httpd_entask (httpd, client, pred, &task, xtnsize);
 }