API save default config file if none specified

api.c

@@ -1976,12 +1976,13 @@ static void devdetails(__maybe_unused SOCKETTYPE c, __maybe_unused char *param,
 
 void dosave(__maybe_unused SOCKETTYPE c, char *param, bool isjson)
 {
+	char filename[PATH_MAX];
 	FILE *fcfg;
 	char *ptr;
 
 	if (param == NULL || *param == '\0') {
-		strcpy(io_buffer, message(MSG_MISFN, 0, NULL, isjson));
-		return;
+		default_save_file(filename);
+		param = filename;
 	}
 
 	fcfg = fopen(param, "w");

cgminer.c

@@ -3006,6 +3006,23 @@ retry:
 }
 #endif
 
+void default_save_file(char *filename)
+{
+#if defined(unix)
+	if (getenv("HOME") && *getenv("HOME")) {
+	        strcpy(filename, getenv("HOME"));
+		strcat(filename, "/");
+	}
+	else
+		strcpy(filename, "");
+	strcat(filename, ".cgminer/");
+	mkdir(filename, 0777);
+#else
+	strcpy(filename, "");
+#endif
+	strcat(filename, def_conf);
+}
+
 #ifdef HAVE_CURSES
 static void set_options(void)
 {
@@ -3066,19 +3083,7 @@ retry:
 		FILE *fcfg;
 		char *str, filename[PATH_MAX], prompt[PATH_MAX + 50];
 
-#if defined(unix)
-		if (getenv("HOME") && *getenv("HOME")) {
-		        strcpy(filename, getenv("HOME"));
-			strcat(filename, "/");
-		}
-		else
-			strcpy(filename, "");
-		strcat(filename, ".cgminer/");
-		mkdir(filename, 0777);
-#else
-		strcpy(filename, "");
-#endif
-		strcat(filename, def_conf);
+		default_save_file(filename);
 		sprintf(prompt, "Config filename to write (Enter for default) [%s]", filename);
 		str = curses_input(prompt);
 		if (strcmp(str, "-1")) {

miner.h

@@ -742,6 +742,7 @@ extern void kill_work(void);
 extern void switch_pools(struct pool *selected);
 extern void remove_pool(struct pool *pool);
 extern void write_config(FILE *fcfg);
+extern void default_save_file(char *filename);
 extern void log_curses(int prio, const char *f, va_list ap);
 extern void clear_logwin(void);
 extern bool pool_tclear(struct pool *pool, bool *var);