diff --git a/nasal.h b/nasal.h
index 3a0051d..29d7f9e 100644
--- a/nasal.h
+++ b/nasal.h
@@ -130,16 +130,19 @@ std::string rawstr(const std::string& str)
 #endif
         switch(i)
         {
-            case '\a': ret+="\\a";break;
-            case '\b': ret+="\\b";break;
-            case '\e': ret+="\\e";break;
-            case '\f': ret+="\\f";break;
-            case '\n': ret+="\\n";break;
-            case '\r': ret+="\\r";break;
-            case '\t': ret+="\\t";break;
-            case '\v': ret+="\\v";break;
-            case '\0': ret+="\\0";break;
-            default:   ret+=i;    break;
+            case '\0': ret+="\\0"; break;
+            case '\a': ret+="\\a"; break;
+            case '\b': ret+="\\b"; break;
+            case '\e': ret+="\\e"; break;
+            case '\t': ret+="\\t"; break;
+            case '\n': ret+="\\n"; break;
+            case '\v': ret+="\\v"; break;
+            case '\f': ret+="\\f"; break;
+            case '\r': ret+="\\r"; break;
+            case '\\': ret+="\\\\";break;
+            case '\'': ret+="\\\'";break;
+            case '\"': ret+="\\\"";break;
+            default:   ret+=i;     break;
         }
     }
     return ret;
diff --git a/nasal_builtin.h b/nasal_builtin.h
index 8440625..d10dbba 100644
--- a/nasal_builtin.h
+++ b/nasal_builtin.h
@@ -1118,7 +1118,8 @@ nasal_ref builtin_environ(nasal_ref* local,nasal_gc& gc)
 nasal_ref builtin_getcwd(nasal_ref* local,nasal_gc& gc)
 {
     char buf[1024];
-    getcwd(buf,sizeof(buf));
+    if(!getcwd(buf,sizeof(buf)))
+        return builtin_err("getcwd","failed to call getcwd");
     nasal_ref str=gc.alloc(vm_str);
     str.str()=buf;
     return str;
diff --git a/nasal_vm.h b/nasal_vm.h
index 2cb5e2c..211fb85 100644
--- a/nasal_vm.h
+++ b/nasal_vm.h
@@ -158,8 +158,8 @@ void nasal_vm::valinfo(nasal_ref& val)
             printf("| str  | <0x%lx> %.16s%s\n",(uint64_t)p,tmp.c_str(),tmp.length()>16?"...":"");
         }break;
         case vm_func: printf("| func | <0x%lx> entry:0x%x\n",(uint64_t)p,val.func().entry);break;
-        case vm_vec:  printf("| vec  | <0x%lx> [%lu val]\n",(uint64_t)p,val.vec().size());break;
-        case vm_hash: printf("| hash | <0x%lx> {%lu val}\n",(uint64_t)p,val.hash().size());break;
+        case vm_vec:  printf("| vec  | <0x%lx> [%zu val]\n",(uint64_t)p,val.vec().size());break;
+        case vm_hash: printf("| hash | <0x%lx> {%zu val}\n",(uint64_t)p,val.hash().size());break;
         case vm_obj:  printf("| obj  | <0x%lx> obj:0x%lx\n",(uint64_t)p,(uint64_t)val.obj().ptr);break;
         default:      printf("| err  | <0x%lx> unknown object\n",(uint64_t)p);break;
     }