ntopng/scripts/plugins/endpoints/shell_alert_endpoint/templates/shell_endpoint.template

<div class="form-group row">
    <label class="col-form-label col-sm-3">
	    <b>{{ i18n("shell_alert_endpoint.shell_script") }}</b>
    </label>
    <div class="col-sm-5">
    <select name="shell_script" class="form-control" required>
        {%
            for key, dir in pairs(ntop.readdir("/usr/share/ntopng")) do 
                if(key:match('^(.*).sh')) then   
        %}
                    <option value='{{ key }}'>{{ dir }}</option>
            {%  
                end  
            %}
        {% 
            end 
        %}
        {%
            for key, dir in pairs(ntop.readdir("scripts/shell")) do 
                if(key:match('^(.*).sh')) then   
        %}
                    <option value='{{ key }}'>{{ dir }}</option>
            {%  
                end  
            %}
        {% 
            end 
        %}
    </select>
    </div>
</div>
<small>{* i18n('shell_alert_endpoint.shell_description.path_description') *}</small>