diff --git a/printlib.php b/printlib.php
index d329895..f1a81e9 100644
--- a/printlib.php
+++ b/printlib.php
@@ -27,7 +27,7 @@ function println($data) {
     }
 }
 function printcode39($data) {
-    if (rawlen($data) and rawlen($data)<8) {
+    if (rawlen($data) and strlen($data)<8) {
         $lp=fopen(PORT, 'w');
         fwrite($lp, "\x1dh\x50");
         fwrite($lp, "\x1dH\x02");
@@ -43,7 +43,7 @@ function printcode39($data) {
     }
 }
 function printcode128($data) {
-    if (rawlen($data)) {
+    if (rawlen($data) and strlen($data)<9) {
         $lp=fopen(PORT, 'w');
         fwrite($lp, "\x1dh\x50");
         fwrite($lp, "\x1dH\x02");
@@ -59,7 +59,7 @@ function printcode128($data) {
     }
 }
 function printean13($data) {
-    if (rawlen($data) and (rawlen($data) == 12 or rawlen($data) == 13)) {
+    if (rawlen($data) and (strlen($data) == 12 or strlen($data) == 13)) {
         $lp=fopen(PORT, 'w');
         fwrite($lp, "\x1dh\x50");
         fwrite($lp, "\x1dH\x02");
@@ -75,7 +75,7 @@ function printean13($data) {
     }
 }
 function printean8($data) {
-    if (rawlen($data) and (rawlen($data) == 7 or rawlen($data) == 8)) {
+    if (rawlen($data) and (strlen($data) == 7 or strlen($data) == 8)) {
         $lp=fopen(PORT, 'w');
         fwrite($lp, "\x1dh\x50");
         fwrite($lp, "\x1dH\x02");