--- a/xdwgrep2.cpp	Sat Mar 24 08:51:45 2018 +0900
+++ b/xdwgrep2.cpp	Tue Apr 03 00:11:01 2018 +0900
@@ -1,12 +1,12 @@
 /* Makefile
-debug: xdwgrep2.c
-	gcc -g -O0 -I. xdwgrep2.c xdwapi.lib
+debug: xdwgrep2.cpp
+	gcc -g -O0 -I. xdwgrep2.cpp xdwapi.lib
 	#date
 	#./a.exe target.xdw
 	#date
 
-release: xdwgrep2.c
-	gcc -I. xdwgrep2.c xdwapi.lib -static -o xdwgrep2.exe
+release: xdwgrep2.cpp
+	gcc -I. xdwgrep2.cpp xdwapi.lib -static -o xdwgrep2.exe
 	strip xdwgrep2.exe
 
 */
@@ -21,7 +21,7 @@
 #include <xdw_api.h>
 
 #define MAXKWORD  256
-#define MAXLINE   256
+#define MAXLINE  4096
 
 void print_error( int code ) {
 	fprintf( stderr, "Error code : %d\n", code );
@@ -52,7 +52,7 @@
 	}
 }
 
-void print_now( char *msg ) {
+void print_now( const char *msg ) {
    time_t now = time( NULL );
    struct tm *ts = localtime( &now );
 
@@ -62,7 +62,7 @@
 }
 
 /* 指定された単語で検索 */
-int xdw_grep( char infile[ _MAX_PATH ], char outfile[ _MAX_PATH ], char keyword[ MAXKWORD ], int inv ) {
+int xdw_grep( const char infile[ _MAX_PATH ], const char outfile[ _MAX_PATH ], const char keyword[ MAXKWORD ], int inv ) {
 
 	char in_path[ _MAX_PATH ], out_path[ _MAX_PATH ], tmp_path[ _MAX_PATH ];
 	_fullpath( in_path,  infile,  _MAX_PATH );
@@ -118,7 +118,7 @@
 }
 
 /* 検索する単語のリストをファイルから読み込む */
-int xdw_grep_list( char infile[ _MAX_PATH ], char outfile[ _MAX_PATH ], bool inv ) {
+int xdw_grep_list( const char infile[ _MAX_PATH ], const char outfile[ _MAX_PATH ], bool inv ) {
 
 	char in_path[ _MAX_PATH ], out_path[ _MAX_PATH ], tmp_path[ _MAX_PATH ];
 	_fullpath( in_path,  infile,  _MAX_PATH );