diff --git a/dhl.sh b/dhl.sh
index 620a737..66c3335 100755
--- a/dhl.sh
+++ b/dhl.sh
@@ -1,5 +1,5 @@
 #!/usr/bin/env sh
-dependencies="sed test cp libreoffice"
+dependencies="sed test cp libreoffice expr"
 assert_tools () {
 	while test $# -gt 0; do
 		which $1  >/dev/null 2>/dev/null || {
@@ -11,6 +11,53 @@ assert_tools () {
 }
 assert_tools ${dependencies}
 
+testcmp () {
+	# usage: testcmp "cmpresult" "cmdfunctionname"  [ "argument1", "argument2", […] ]
+	if test "$#" -eq 0 ; then
+		echo "arguments missing."; exit 1
+	fi
+	case $2 in 
+	#whitelisted fn
+	chklength)
+		expect="$1"; shift
+		fn="$1"; shift
+		result=$("$fn" "$1" "$2")
+		if test "$result" = "$expect" ; then
+			echo "$fn passed for: $1 $2."
+		else
+			echo "$fn failed for: $1 $2."
+		fi
+	;;
+	iso3countrycode)
+		expect="$1"; shift
+		fn="$1"; shift
+		for a in "$@"; do 
+			result=$("$fn" "$a")
+			if test "$result" = "$expect" ; then
+				echo "$fn passed for: $a."
+			else
+				echo "$fn failed for: $a."
+			fi
+		done
+	;;
+	*)
+		echo "no test performed, function or command not allowd."
+	esac
+}
+
+chklength () {
+	test "$#" -eq "0" && { echo "-1"; }
+	expect="$1"; shift
+	result=$(expr length "$1")
+	test "$expect" -eq "$result" && { echo "true"; } || { echo "$result"; }
+}
+
+testchklength () {
+	chklength "3" "123"
+	testcmp "true" "chklength" "3" "123"
+	testcmp "3" "chklength" "2" "1-2"
+}
+
 # target filename
 tn="dhl-cp1252.csv"
 
@@ -23,11 +70,6 @@ cp -f "${fn}" "${fn}.bak"
 # replace special spaces and hyphens
 sed -i -e 's/[\u00A0\u202F[:space:]]+/ /g' -e 's/[\u2010\u2011\u2012\u2013\u002D]+/-/g' -e 's/[\u00AD\uFEFF]+//g' "$fn"
 
-# todo: convert encoding from UTF-8 to CP1252 "Windows"
-
-# a possibility for conversion? seems not to be reliant
-#~ iconv -o "$tn" -f UTF-8 -t CP1252 "$fn" 
-
 # todo: validate length for entries
 
 # todo: convert country to countrycode as in ISO3
@@ -49,32 +91,6 @@ iso3countrycode () {
 	fi
 }
 
-testcmp () {
-	# usage: testcmp "cmpresult" "cmdfunctionname"  [ "argument1", "argument2", […] ]
-	if test "$#" -eq 0 ; then
-		echo "arguments missing."; exit 1
-	fi
-	case $2 in 
-	#whitelisted fn
-	iso3countrycode)
-		expected="$1"
-		shift
-		fn="$1"
-		shift
-		for a in "$@"; do 
-			result=$("$fn" "$a")
-			if test "$result" = "$expected" ; then
-				echo "$fn passed for: $a."
-			else
-				echo "$fn failed for: $a."
-			fi
-		done
-		;;
-	*)
-		echo "no test performed, function or command not allowd."
-	esac
-}
-
 testiso3 () {
 	# covering data in https://doku.ccc.de/index.php?title=Attribut:Chaostreff-Country&limit=500&offset=0
 	testcmp "BEL" "iso3countrycode" "Belgien"
@@ -89,10 +105,11 @@ testiso3 () {
 }
 #~ testiso3
 
+# convert encoding from UTF-8 to CP1252 "Windows"
+# another possibility for conversion? seems not to be relyable: iconv -o "$of" -f UTF-8 -t CP1252 "$if" 
 convcsv () {
 	if test $# -eq 0 ; then echo "argument missing."; exit 1; fi
 	if test -e $1 ; then echo "file already exists."; exit 2; fi 
-# charset windows codepage 1252
 # doc for headless conversion options https://wiki.openoffice.org/wiki/Documentation/DevGuide/Spreadsheets/Filter_Options
 	if="${1}"
 	of=$(echo "${if}"|rev|cut -d. -f2-|rev)".ods"