diff --git a/usr.bin/lex/NEWS b/usr.bin/lex/NEWS
index e4ba93fe3d23..3e23e7d9f623 100644
--- a/usr.bin/lex/NEWS
+++ b/usr.bin/lex/NEWS
@@ -1,3 +1,14 @@
+Changes between release 2.5.4 (11Sep96) and release 2.5.3:
+
+	- Fixed a bug introduced in 2.5.3 that blew it when a call
+	  to input() occurred at the end of an input file.
+
+	- Fixed scanner skeleton so the example in the man page of
+	  scanning strings using exclusive start conditions works.
+
+	- Minor Makefile tweaks.
+
+
 Changes between release 2.5.3 (29May96) and release 2.5.2:
 
 	- Some serious bugs in yymore() have been fixed.  In particular,
diff --git a/usr.bin/lex/flex.skl b/usr.bin/lex/flex.skl
index 67ebe57f0b92..71a9cb649f9c 100644
--- a/usr.bin/lex/flex.skl
+++ b/usr.bin/lex/flex.skl
@@ -1,7 +1,7 @@
 /* A lexical scanner generated by flex */
 
 /* Scanner skeleton version:
- * $Header: /home/daffy/u0/vern/flex/RCS/flex.skl,v 2.89 96/05/25 21:02:21 vern Exp $
+ * $Header: /home/daffy/u0/vern/flex/RCS/flex.skl,v 2.91 96/09/10 16:58:48 vern Exp $
  */
 
 #define FLEX_SCANNER
@@ -250,7 +250,7 @@ void yy_flush_buffer YY_PROTO(( YY_BUFFER_STATE b ));
 #define YY_FLUSH_BUFFER yy_flush_buffer( yy_current_buffer )
 
 YY_BUFFER_STATE yy_scan_buffer YY_PROTO(( char *base, yy_size_t size ));
-YY_BUFFER_STATE yy_scan_string YY_PROTO(( yyconst char *str ));
+YY_BUFFER_STATE yy_scan_string YY_PROTO(( yyconst char *yy_str ));
 YY_BUFFER_STATE yy_scan_bytes YY_PROTO(( yyconst char *bytes, int len ));
 %*
 
@@ -783,7 +783,7 @@ int yyFlexLexer::yy_get_next_buffer()
 		/* don't do the read, it's not guaranteed to return an EOF,
 		 * just force an EOF
 		 */
-		yy_n_chars = 0;
+		yy_current_buffer->yy_n_chars = yy_n_chars = 0;
 
 	else
 		{
@@ -838,6 +838,8 @@ int yyFlexLexer::yy_get_next_buffer()
 		/* Read in more data. */
 		YY_INPUT( (&yy_current_buffer->yy_ch_buf[number_to_move]),
 			yy_n_chars, num_to_read );
+
+		yy_current_buffer->yy_n_chars = yy_n_chars;
 		}
 
 	if ( yy_n_chars == 0 )
@@ -947,7 +949,8 @@ void yyFlexLexer::yyunput( int c, register char* yy_bp )
 
 		yy_cp += (int) (dest - source);
 		yy_bp += (int) (dest - source);
-		yy_n_chars = yy_current_buffer->yy_buf_size;
+		yy_current_buffer->yy_n_chars =
+			yy_n_chars = yy_current_buffer->yy_buf_size;
 
 		if ( yy_cp < yy_current_buffer->yy_ch_buf + 2 )
 			YY_FATAL_ERROR( "flex scanner push-back overflow" );
@@ -997,13 +1000,26 @@ int yyFlexLexer::yyinput()
 
 			switch ( yy_get_next_buffer() )
 				{
+				case EOB_ACT_LAST_MATCH:
+					/* This happens because yy_g_n_b()
+					 * sees that we've accumulated a
+					 * token and flags that we need to
+					 * try matching the token before
+					 * proceeding.  But for input(),
+					 * there's no matching to consider.
+					 * So convert the EOB_ACT_LAST_MATCH
+					 * to EOB_ACT_END_OF_FILE.
+					 */
+
+					/* Reset buffer status. */
+					yyrestart( yyin );
+
+					/* fall through */
+
 				case EOB_ACT_END_OF_FILE:
 					{
 					if ( yywrap() )
-						{
-						yy_c_buf_p = yytext_ptr + offset;
 						return EOF;
-						}
 
 					if ( ! yy_did_buffer_switch_on_eof )
 						YY_NEW_FILE;
@@ -1017,15 +1033,6 @@ int yyFlexLexer::yyinput()
 				case EOB_ACT_CONTINUE_SCAN:
 					yy_c_buf_p = yytext_ptr + offset;
 					break;
-
-				case EOB_ACT_LAST_MATCH:
-#ifdef __cplusplus
-					YY_FATAL_ERROR(
-					"unexpected last match in yyinput()" );
-#else
-					YY_FATAL_ERROR(
-					"unexpected last match in input()" );
-#endif
 				}
 			}
 		}
@@ -1223,6 +1230,9 @@ YY_BUFFER_STATE b;
 void yyFlexLexer::yy_flush_buffer( YY_BUFFER_STATE b )
 %*
 	{
+	if ( ! b )
+		return;
+
 	b->yy_n_chars = 0;
 
 	/* We always need two end-of-buffer characters.  The first causes
@@ -1286,17 +1296,17 @@ yy_size_t size;
 #ifndef YY_NO_SCAN_STRING
 %-
 #ifdef YY_USE_PROTOS
-YY_BUFFER_STATE yy_scan_string( yyconst char *str )
+YY_BUFFER_STATE yy_scan_string( yyconst char *yy_str )
 #else
-YY_BUFFER_STATE yy_scan_string( str )
-yyconst char *str;
+YY_BUFFER_STATE yy_scan_string( yy_str )
+yyconst char *yy_str;
 #endif
 	{
 	int len;
-	for ( len = 0; str[len]; ++len )
+	for ( len = 0; yy_str[len]; ++len )
 		;
 
-	return yy_scan_bytes( str, len );
+	return yy_scan_bytes( yy_str, len );
 	}
 %*
 #endif
diff --git a/usr.bin/lex/initscan.c b/usr.bin/lex/initscan.c
index 99815f12f34b..1ca9fa58d7cb 100644
--- a/usr.bin/lex/initscan.c
+++ b/usr.bin/lex/initscan.c
@@ -2,7 +2,7 @@
 /* A lexical scanner generated by flex */
 
 /* Scanner skeleton version:
- * $Header: /home/daffy/u0/vern/flex/RCS/flex.skl,v 2.89 96/05/25 21:02:21 vern Exp $
+ * $Header: /home/daffy/u0/vern/flex/RCS/flex.skl,v 2.91 96/09/10 16:58:48 vern Exp $
  */
 
 #define FLEX_SCANNER
@@ -237,7 +237,7 @@ void yy_flush_buffer YY_PROTO(( YY_BUFFER_STATE b ));
 #define YY_FLUSH_BUFFER yy_flush_buffer( yy_current_buffer )
 
 YY_BUFFER_STATE yy_scan_buffer YY_PROTO(( char *base, yy_size_t size ));
-YY_BUFFER_STATE yy_scan_string YY_PROTO(( yyconst char *str ));
+YY_BUFFER_STATE yy_scan_string YY_PROTO(( yyconst char *yy_str ));
 YY_BUFFER_STATE yy_scan_bytes YY_PROTO(( yyconst char *bytes, int len ));
 
 static void *yy_flex_alloc YY_PROTO(( yy_size_t ));
@@ -2929,7 +2929,7 @@ static int yy_get_next_buffer()
 		/* don't do the read, it's not guaranteed to return an EOF,
 		 * just force an EOF
 		 */
-		yy_n_chars = 0;
+		yy_current_buffer->yy_n_chars = yy_n_chars = 0;
 
 	else
 		{
@@ -2984,6 +2984,8 @@ static int yy_get_next_buffer()
 		/* Read in more data. */
 		YY_INPUT( (&yy_current_buffer->yy_ch_buf[number_to_move]),
 			yy_n_chars, num_to_read );
+
+		yy_current_buffer->yy_n_chars = yy_n_chars;
 		}
 
 	if ( yy_n_chars == 0 )
@@ -3109,7 +3111,8 @@ register char *yy_bp;
 
 		yy_cp += (int) (dest - source);
 		yy_bp += (int) (dest - source);
-		yy_n_chars = yy_current_buffer->yy_buf_size;
+		yy_current_buffer->yy_n_chars =
+			yy_n_chars = yy_current_buffer->yy_buf_size;
 
 		if ( yy_cp < yy_current_buffer->yy_ch_buf + 2 )
 			YY_FATAL_ERROR( "flex scanner push-back overflow" );
@@ -3152,13 +3155,26 @@ static int input()
 
 			switch ( yy_get_next_buffer() )
 				{
+				case EOB_ACT_LAST_MATCH:
+					/* This happens because yy_g_n_b()
+					 * sees that we've accumulated a
+					 * token and flags that we need to
+					 * try matching the token before
+					 * proceeding.  But for input(),
+					 * there's no matching to consider.
+					 * So convert the EOB_ACT_LAST_MATCH
+					 * to EOB_ACT_END_OF_FILE.
+					 */
+
+					/* Reset buffer status. */
+					yyrestart( yyin );
+
+					/* fall through */
+
 				case EOB_ACT_END_OF_FILE:
 					{
 					if ( yywrap() )
-						{
-						yy_c_buf_p = yytext_ptr + offset;
 						return EOF;
-						}
 
 					if ( ! yy_did_buffer_switch_on_eof )
 						YY_NEW_FILE;
@@ -3172,15 +3188,6 @@ static int input()
 				case EOB_ACT_CONTINUE_SCAN:
 					yy_c_buf_p = yytext_ptr + offset;
 					break;
-
-				case EOB_ACT_LAST_MATCH:
-#ifdef __cplusplus
-					YY_FATAL_ERROR(
-					"unexpected last match in yyinput()" );
-#else
-					YY_FATAL_ERROR(
-					"unexpected last match in input()" );
-#endif
 				}
 			}
 		}
@@ -3345,6 +3352,9 @@ YY_BUFFER_STATE b;
 #endif
 
 	{
+	if ( ! b )
+		return;
+
 	b->yy_n_chars = 0;
 
 	/* We always need two end-of-buffer characters.  The first causes
@@ -3404,17 +3414,17 @@ yy_size_t size;
 
 #ifndef YY_NO_SCAN_STRING
 #ifdef YY_USE_PROTOS
-YY_BUFFER_STATE yy_scan_string( yyconst char *str )
+YY_BUFFER_STATE yy_scan_string( yyconst char *yy_str )
 #else
-YY_BUFFER_STATE yy_scan_string( str )
-yyconst char *str;
+YY_BUFFER_STATE yy_scan_string( yy_str )
+yyconst char *yy_str;
 #endif
 	{
 	int len;
-	for ( len = 0; str[len]; ++len )
+	for ( len = 0; yy_str[len]; ++len )
 		;
 
-	return yy_scan_bytes( str, len );
+	return yy_scan_bytes( yy_str, len );
 	}
 #endif
 
diff --git a/usr.bin/lex/skel.c b/usr.bin/lex/skel.c
index adf710fc21fa..3354600fae25 100644
--- a/usr.bin/lex/skel.c
+++ b/usr.bin/lex/skel.c
@@ -6,7 +6,7 @@ const char *skel[] = {
   "/* A lexical scanner generated by flex */",
   "",
   "/* Scanner skeleton version:",
-  " * $Header: /home/daffy/u0/vern/flex/RCS/flex.skl,v 2.89 96/05/25 21:02:21 vern Exp $",
+  " * $Header: /home/daffy/u0/vern/flex/RCS/flex.skl,v 2.91 96/09/10 16:58:48 vern Exp $",
   " */",
   "",
   "#define FLEX_SCANNER",
@@ -255,7 +255,7 @@ const char *skel[] = {
   "#define YY_FLUSH_BUFFER yy_flush_buffer( yy_current_buffer )",
   "",
   "YY_BUFFER_STATE yy_scan_buffer YY_PROTO(( char *base, yy_size_t size ));",
-  "YY_BUFFER_STATE yy_scan_string YY_PROTO(( yyconst char *str ));",
+  "YY_BUFFER_STATE yy_scan_string YY_PROTO(( yyconst char *yy_str ));",
   "YY_BUFFER_STATE yy_scan_bytes YY_PROTO(( yyconst char *bytes, int len ));",
   "%*",
   "",
@@ -788,7 +788,7 @@ const char *skel[] = {
   "		/* don't do the read, it's not guaranteed to return an EOF,",
   "		 * just force an EOF",
   "		 */",
-  "		yy_n_chars = 0;",
+  "		yy_current_buffer->yy_n_chars = yy_n_chars = 0;",
   "",
   "	else",
   "		{",
@@ -843,6 +843,8 @@ const char *skel[] = {
   "		/* Read in more data. */",
   "		YY_INPUT( (&yy_current_buffer->yy_ch_buf[number_to_move]),",
   "			yy_n_chars, num_to_read );",
+  "",
+  "		yy_current_buffer->yy_n_chars = yy_n_chars;",
   "		}",
   "",
   "	if ( yy_n_chars == 0 )",
@@ -952,7 +954,8 @@ const char *skel[] = {
   "",
   "		yy_cp += (int) (dest - source);",
   "		yy_bp += (int) (dest - source);",
-  "		yy_n_chars = yy_current_buffer->yy_buf_size;",
+  "		yy_current_buffer->yy_n_chars =",
+  "			yy_n_chars = yy_current_buffer->yy_buf_size;",
   "",
   "		if ( yy_cp < yy_current_buffer->yy_ch_buf + 2 )",
   "			YY_FATAL_ERROR( \"flex scanner push-back overflow\" );",
@@ -1002,13 +1005,26 @@ const char *skel[] = {
   "",
   "			switch ( yy_get_next_buffer() )",
   "				{",
+  "				case EOB_ACT_LAST_MATCH:",
+  "					/* This happens because yy_g_n_b()",
+  "					 * sees that we've accumulated a",
+  "					 * token and flags that we need to",
+  "					 * try matching the token before",
+  "					 * proceeding.  But for input(),",
+  "					 * there's no matching to consider.",
+  "					 * So convert the EOB_ACT_LAST_MATCH",
+  "					 * to EOB_ACT_END_OF_FILE.",
+  "					 */",
+  "",
+  "					/* Reset buffer status. */",
+  "					yyrestart( yyin );",
+  "",
+  "					/* fall through */",
+  "",
   "				case EOB_ACT_END_OF_FILE:",
   "					{",
   "					if ( yywrap() )",
-  "						{",
-  "						yy_c_buf_p = yytext_ptr + offset;",
   "						return EOF;",
-  "						}",
   "",
   "					if ( ! yy_did_buffer_switch_on_eof )",
   "						YY_NEW_FILE;",
@@ -1022,15 +1038,6 @@ const char *skel[] = {
   "				case EOB_ACT_CONTINUE_SCAN:",
   "					yy_c_buf_p = yytext_ptr + offset;",
   "					break;",
-  "",
-  "				case EOB_ACT_LAST_MATCH:",
-  "#ifdef __cplusplus",
-  "					YY_FATAL_ERROR(",
-  "					\"unexpected last match in yyinput()\" );",
-  "#else",
-  "					YY_FATAL_ERROR(",
-  "					\"unexpected last match in input()\" );",
-  "#endif",
   "				}",
   "			}",
   "		}",
@@ -1228,6 +1235,9 @@ const char *skel[] = {
   "void yyFlexLexer::yy_flush_buffer( YY_BUFFER_STATE b )",
   "%*",
   "	{",
+  "	if ( ! b )",
+  "		return;",
+  "",
   "	b->yy_n_chars = 0;",
   "",
   "	/* We always need two end-of-buffer characters.  The first causes",
@@ -1291,17 +1301,17 @@ const char *skel[] = {
   "#ifndef YY_NO_SCAN_STRING",
   "%-",
   "#ifdef YY_USE_PROTOS",
-  "YY_BUFFER_STATE yy_scan_string( yyconst char *str )",
+  "YY_BUFFER_STATE yy_scan_string( yyconst char *yy_str )",
   "#else",
-  "YY_BUFFER_STATE yy_scan_string( str )",
-  "yyconst char *str;",
+  "YY_BUFFER_STATE yy_scan_string( yy_str )",
+  "yyconst char *yy_str;",
   "#endif",
   "	{",
   "	int len;",
-  "	for ( len = 0; str[len]; ++len )",
+  "	for ( len = 0; yy_str[len]; ++len )",
   "		;",
   "",
-  "	return yy_scan_bytes( str, len );",
+  "	return yy_scan_bytes( yy_str, len );",
   "	}",
   "%*",
   "#endif",
diff --git a/usr.bin/lex/version.h b/usr.bin/lex/version.h
index a7c072c00b8d..623ca12a6d0b 100644
--- a/usr.bin/lex/version.h
+++ b/usr.bin/lex/version.h
@@ -1 +1 @@
-#define FLEX_VERSION "2.5.3"
+#define FLEX_VERSION "2.5.4"