a php program acting like ' tail '

I need something to monitor log files via browser the log file is like apache access_log i can use tail -f to monitor it. now I want a web page to display the content of the log in the way of tail -f the record should scroll automatically requirement 1, php is better 2, configure - able 3, a well organized UI, simple but clean 4, most of the strings in the log file are url encoded, I need decoded string display on the web. eg. q=%E4%BD%A0%E5%A5%BD that should be decoded. 5, filter out the interested part of the log eg. key_word = boy+girl+women+men => boy girl women men