Edit in JSFiddle

(function ($) {
    $('#select_options').on('click', function () {

        if ($.trim('#texts_to_select') == "") return;

        var texts_to_select = $('#texts_to_select').val().split(',');
        var selected_values = [];

        $("#languages7 option").each(function (k, v) {

            if (texts_to_select.indexOf($(v).filter('option').text()) >= 0) {

                selected_values.push($(v).filter('option').val());
            }
        });

        $('#languages7').val(selected_values);


    });
})(jQuery);
<label for="">Text to Select</label>
<input type="text" placeholder="PHP,PERL" id="texts_to_select" class="form-control">(comma separated)
<input type="button" value="Select" class="btn btn-primary" value="Select Multiple" id="select_options">
<br/>(should be CAPS as visible in dropdown and not its value)
<br/>
<div class="code_example">
    <select name="languages" id="languages7" multiple>
        <option value="c">C</option>
        <option value="c++">C++</option>
        <option value="php">PHP</option>
        <option value="perl">PERL</option>
        <option value="ruby">RUBY</option>
        <option value="python">PYTHON</option>
        <option value="go">GO</option>
    </select>
</div>