diff --git a/rdasr.c b/rdasr.c
index 332da5ae36cffb2dbecebbdadd2ccad0459fafcf..10bb240d673ed567a47a6400136bf782e00f2b6b 100644
--- a/rdasr.c
+++ b/rdasr.c
@@ -18,6 +18,7 @@
 #include <sys/stat.h>
 #include <sys/ioctl.h>
 #include <unistd.h>
+#include <limits.h>
 #include "version.h"
 #include "sysreg.h"
 
@@ -81,7 +82,12 @@ int search(void)
 	FILE *fp;
 
 	if ((fp = fopen(TABLEPATH, "r")) == NULL) {
-		printf("%s: No such file or can not read!\n", TABLEPATH);
+		fprintf(stderr, "%s: No such file or can not read!\n\
+                       an register table you can find:\n\
+                          https://github.com/alibaba/system-register-tools/blob/main/registersv8.table\n\
+                       download and move this configure:\n\
+                          wget <above link> -o ~/.regstable\n\
+                       or move this file into '/root/' if you are root user!\n", TABLEPATH);
 		return -1;
 	}
 
@@ -152,7 +158,7 @@ int test_all(void)
 	FILE *fp;
 
 	if ((fp = fopen(TABLEPATH, "r")) == NULL) {
-		printf("%s: No such file or can not read!\n", TABLEPATH);
+		fprintf(stderr, "%s: No such file or can not read!\n", TABLEPATH);
 		return -1;
 	}
 
@@ -223,10 +229,10 @@ void parse(const char *regname)
 {
 	int status;
 	int op0, op1, cn, cm, op2;
-	unsigned int len = 0;
+	unsigned int len = strlen(regname);
 
 	global_register = (struct register_t *)malloc(sizeof(struct register_t));
-	global_register->length = strlen(regname);
+	global_register->length = len;
 	global_register->name = strdup(regname);
 
 	/* check the format of register name */
@@ -272,7 +278,7 @@ int main(int argc, char *argv[])
 	unsigned int highbit = 63, lowbit = 0;
 	unsigned long arg;
 	char *endarg;
-	char msr_file_name[64];
+	char msr_file_name[NAME_MAX];
 
 	program = argv[0];
 	/* check the usage of program */
diff --git a/wrasr.c b/wrasr.c
index 4520d24d04421a8af809ada597fcec3a49db5fa7..421a0f8ef0b116a0f22569efb36cf13ef5c122fe 100644
--- a/wrasr.c
+++ b/wrasr.c
@@ -15,6 +15,7 @@
 #include <sys/types.h>
 #include <sys/sysinfo.h>
 #include <unistd.h>
+#include <limits.h>
 #include "version.h"
 #include "sysreg.h"
 
@@ -102,7 +103,13 @@ int search(void)
 	FILE *fp;
 
 	if ((fp = fopen(TABLEPATH, "r")) == NULL) {
-		printf("%s: No such file or can not read!\n", TABLEPATH);
+		fprintf(stderr, "%s: No such file or can not read!\n\
+                       an register table you can find:\n\
+                          https://github.com/alibaba/system-register-tools/blob/main/registersv8.table\n\
+                       download and move this configure:\n\
+                          wget <above link> -o ~/.regstable\n\
+                       or move this file into '/root/' if you are root user!\n", TABLEPATH);
+
 		return -1;
 	}
 
@@ -186,7 +193,7 @@ int main(int argc, char *argv[])
 	unsigned int highbit = 63, lowbit = 0;
 	unsigned long arg;
 	char *endarg;
-	char msr_file_name[64];
+	char msr_file_name[NAME_MAX];
 
 	program = argv[0];
 	init();