How to select the text of a span on click?

It could be implemented with native JavaScript. A working demonstration on jsFiddle. Your code could be like this:

$('.unc_path').click(function (){
    var range, selection;

    if (window.getSelection && document.createRange) {
        selection = window.getSelection();
        range = document.createRange();
        range.selectNodeContents(this);
        selection.removeAllRanges();
        selection.addRange(range);
    } else if (document.selection && document.body.createTextRange) {
        range = document.body.createTextRange();
        range.moveToElementText(this);
        range.select();
    }
});