diff --git a/exec.c b/exec.c
index 4f0cd04..136be1a 100644
--- a/exec.c
+++ b/exec.c
@@ -2,7 +2,7 @@
  * @Author: 1ridic
  * @Date: 2022-09-18 14:14:23
  * @Last Modified by: 1ridic
- * @Last Modified time: 2022-09-18 23:31:39
+ * @Last Modified time: 2022-09-20 22:24:51
  */
 #include "builtin.h"
 #include <stdio.h>
@@ -31,17 +31,13 @@ int forkExec(char **args) {
     /* fork error */
     perror("dish");
   } else {
-    extern char volatile isWaiting;
-    isWaiting = 1;
     /* parent process: wait child process*/
     int stat_val;
     waitpid(pid, &stat_val, 0);
     if (WIFEXITED(stat_val)) {
-      isWaiting = 0;
       return WEXITSTATUS(stat_val);
     }
     else if (WIFSIGNALED(stat_val)) {
-      isWaiting = 1;
       return WTERMSIG(stat_val);
     }
   }
diff --git a/loop.c b/loop.c
index 1460839..790306b 100644
--- a/loop.c
+++ b/loop.c
@@ -2,7 +2,7 @@
  * @Author: 1ridic
  * @Date: 2022-09-18 14:13:53
  * @Last Modified by: 1ridic
- * @Last Modified time: 2022-09-18 23:32:02
+ * @Last Modified time: 2022-09-20 22:26:59
  */
 #include <stdio.h>
 #include <readline/readline.h>
@@ -15,6 +15,20 @@
 
 int status;
 
+void SIGINT_Handler(int dummy) {
+#ifdef DEBUG
+  fprintf(stdout,"\ndebug: SIGINT\n");
+#endif
+  /* Move to a new line */
+  fprintf(stdout,"\n");
+  /* Regenerate the prompt on a newline */
+  rl_on_new_line();
+  /* Clear the previous text */
+  rl_replace_line("", 0);
+  rl_redisplay();
+  return;
+}
+
 int loop() {
 
   char *line;
diff --git a/loop.h b/loop.h
index d5f4c48..dbe9333 100644
--- a/loop.h
+++ b/loop.h
@@ -1,11 +1,12 @@
 /*
  * @Author: 1ridic 
  * @Date: 2022-09-18 14:14:19 
- * @Last Modified by:   1ridic 
- * @Last Modified time: 2022-09-18 14:14:19 
+ * @Last Modified by: 1ridic
+ * @Last Modified time: 2022-09-20 22:24:24
  */
 #ifndef _LOOP_H_
 #define _LOOP_H_
 #include "config.h"
+void SIGINT_Handler(int dummy);
 int loop();
 #endif
\ No newline at end of file
diff --git a/main.c b/main.c
index 4403875..6553d99 100644
--- a/main.c
+++ b/main.c
@@ -2,7 +2,7 @@
  * @Author: 1ridic 
  * @Date: 2022-09-18 14:13:59 
  * @Last Modified by: 1ridic
- * @Last Modified time: 2022-09-18 23:21:37
+ * @Last Modified time: 2022-09-20 22:23:59
  */
 #include <signal.h>
 #include <stdio.h>
@@ -11,22 +11,10 @@
 #include <string.h>
 #include "loop.h"
 
-char volatile isWaiting = 0; 
-void intHandler(int dummy) {
-#ifdef DEBUG
-  fprintf(stdout,"\ndebug: enter soft-irq. isWaiting=%d\n",isWaiting);
-#endif
-  if (isWaiting==1) {
-    return;
-  }
-  fprintf(stderr,"\nSIGINT exit.\n");
-  exit(EXIT_FAILURE);
-  
-}
 
 int main(int argc, char *argv[]) {
   /* soft irq */
-  signal(SIGINT, intHandler);
+  signal(SIGINT, SIGINT_Handler);
   /* clear screen */
   fprintf(stdout,"\033[H\033[J");
 #ifdef DEBUG