which language do i need to use for processing 500gb of data?

i have a server filled with 500GB of docx, pptx, html files, pdfs etc. I wanted to create a search engine where all these files will b crawled nd indexed! I wud like to know which programming language should i rely on? Am an expert php developer! I found php works good, but it takes alot of time to crawl nd process each file! Any solution or suggestions? Do i need to code in python, perl, c, c++, java or in ruby on rails?