fopen() / browser identification

i use fopen("http://catalog.loc.gov/cgi-bin/Pwebrecon.cgi? DB=local&PAGE=hbSearch", "r") to read and parse a file located on the internet. it seems, that the website i'm trying to access looks for some browser identification, and refuses my request. my question is thus: does an fopen() send some kind of browser identification to the site, and if not, is there a way to spoof this information anyway. or should i resort to a makeshift and use lynx? cc to me appreciated (i'm getting the digest version). thanks a lot, Jakob.