Small portability fix

diff --git a/ext/ext_skel b/ext/ext_skel
index f432d570c1cac99adf4798e8f10c213b840898bf..12fe17bd32b482affc0bc88d937f1dc5e7314bf2 100755 (executable)
--- a/ext/ext_skel
+++ b/ext/ext_skel
@@ -35,7 +35,7 @@ while test $# -gt 0; do
   case $1 in
     --extname=?*)
        extname=$optarg
-       EXTNAME=`echo $extname | tr a-z A-Z`
+       EXTNAME=`echo $extname | tr [a-z] [A-Z]`
        ;;
     --proto=?*)
        proto=$optarg