add return code check for system

install.pl

@@ -176,6 +176,9 @@ sub install_printer {
     }
 
     system($command);
+    if ($? != 0) {
+        die "[ERROR] Could not install the printer via lpadmin";
+    }
 
     return;
 }
@@ -188,6 +191,9 @@ sub update_ppd {
     -P "ppds/${printer_name}.ppd" );
 
     system($command);
+    if ($? != 0) {
+        die "[ERROR] Could not update the ppd via lpadmin";
+    }
 
     return;
 }