implemented safe printing for nonprintable characters

src/main/sm_common.c

@@ -123,3 +123,20 @@ void sm_log(const char *format, ...) {
   va_end(args);
   fclose(fp);
 }
+
+void sm_print_string(sm_string *str) {
+  for (int i = 0; i < str->size; i++)
+    putc((&str->content)[i], stdout);
+}
+
+void sm_safe_print_string(sm_string *str) {
+  for (int i = 0; i < str->size; i++) {
+    char ch = (&str->content)[i];
+    if (isprint(ch) || isspace(ch))
+      putc(ch, stdout);
+    else
+      // Escape non-printable characters
+      printf("\\x%02X", (unsigned char)ch);
+  }
+  fflush(stdout);
+}

src/main/sm_common.h

@@ -25,3 +25,8 @@ bool sm_is_symbol_char(char c);
 /// Write a log message to sms.log for debugging.
 /// Works just like printf
 void sm_log(const char *format, ...);
+
+/// Print a string, only regarding string size, not NULL termination
+void sm_print_string(struct sm_string *str);
+/// Print a string, trusting string size, but replacing non-printables with hex
+void sm_safe_print_string(struct sm_string *str);

src/main/sm_main.c

@@ -42,8 +42,9 @@ void start_repl(sm_env *env) {
       sm_object *result = sm_engine_eval(pr.parsed_object, *(sm_global_lex_stack(NULL)->top), NULL);
       // Print
       sm_string *result_str = sm_object_to_string(result);
-      printf("%s%s%s", sm_terminal_fg_color(SM_TERM_B_WHITE), &(result_str->content),
-             sm_terminal_reset());
+      printf("%s", sm_terminal_fg_color(SM_TERM_B_WHITE));
+      sm_safe_print_string(result_str);
+      printf("%s", sm_terminal_reset());
       // Cleanup
       sm_garbage_collect();
       fflush(stdout);