--- ./main_loop.c	2019/04/15 15:00:20	1.1
+++ ./main_loop.c	2019/04/15 15:03:52
@@ -29,7 +29,8 @@
 
 static char def_filename[1024] = "";	/* default filename */
 static char errmsg[80] = "";		/* error message buffer */
-static char prompt_str[80] = "*";	/* command prompt */
+static char default_prompt_str[2] = "*";	/* default command prompt */
+static char * prompt_str = default_prompt_str;	/* command prompt */
 static int first_addr = 0, second_addr = 0;
 static bool prompt_on = false;		/* if set, show command prompt */
 static bool verbose = false;		/* if set, print all error messages */
@@ -50,9 +51,16 @@
 
 void set_prompt( const char * const s )
   {
+  size_t new_len;
+  char * new_prompt;
   prompt_on = true;
-  strncpy( prompt_str, s, sizeof prompt_str );
-  prompt_str[sizeof(prompt_str)-1] = 0;
+  new_len = strlen(s) + 1;
+  if ((new_prompt = malloc(new_len)))
+    if (strcpy(new_prompt, s))
+      {
+        if (prompt_str != default_prompt_str) free(prompt_str);
+        prompt_str = new_prompt;
+      }
   }
 
 void set_verbose( void ) { verbose = true; }