#*

  Only print (some) urls in the input stream. A simple 
  non-parsing see-and-print script.

*#

read;
B"http://",B"https://",B"www.",B"ftp://" {
  E" ",E"\n",(eof) { add "\n"; print; clear; }
}
E" ",E"\n",(eof) { clear; }