<input type="text" id="input1" value="url을 http://b1ix.net.... 자동으로 a태그로 치환해줌">
<button id="btn1">A태그로 치환</button>
<div id="div1"></div>

<script>
function url2atag(text){
	if( !text ) return '';

	return String(text).replace(/(\b(https?|ftp|file):\/\/[\-A-Z0-9+&@#\/%?=~_|!:,.;]*[\-A-Z0-9+&@#\/%=~_|])/img, '<a href="$1" target="_blank">$1</a>')
}

$(function(){
	$(document).on('click', '#btn1', function(){
		$('#div1').html( url2atag($('#input1').val()) )
	})
})
</script>