update the help display

README.md

@@ -96,7 +96,7 @@ bashopts_process_args
 ## Example
 
 ```bash
-#!/bin/bash -e
+#!/bin/bash -ei
 
 # load the library
 . bashopts.sh

bashopts.sh

@@ -266,6 +266,10 @@ bashopts_math_max() {
     echo $(($1>$2?$1:$2))
 }
 
+bashopts_math_min() {
+    echo $(($1<$2?$1:$2))
+}
+
 bashopts_join_by() {
     local IFS="$1"
     shift
@@ -304,7 +308,7 @@ bashopts_dump_value() {
 }
 
 bashopts_diplay_help() {
-    local elts optargs_max_len=8 val dval
+    local elts optargs_max_len=8 val dval ncol=$COLUMNS
     declare -A optargs
     for op in "${bashopts_optlist[@]}"; do
         elts=()
@@ -317,6 +321,9 @@ bashopts_diplay_help() {
         optargs[$op]="$(bashopts_join_by , ${elts[@]})$val"
         optargs_max_len=$(bashopts_math_max $optargs_max_len ${#optargs[$op]})
     done
+    ncol=${ncol:-160}
+    optargs_max_len=$(bashopts_math_min $optargs_max_len $(( $ncol / 3 )) )
+    set +x
     echo
     echo "NAME:"
     echo "    $bashopts_tool_name - $bashopts_tool_description"

example.sh

-#!/bin/bash -e
+#!/bin/bash -ei
 
 # load the library
 . bashopts.sh

test.sh

-#!/bin/bash -e
+#!/bin/bash -ei
 # Copyright 2017 Emeric Verschuur <emeric@mbedsys.org>
 #
 # Licensed to the Apache Software Foundation (ASF) under one