Dan writes "Based on Sam Leffer's suggestion, Bruce Simpson has been working on refactoring ifconfig(8). ifconfig is a FreeBSD unix utility used to assign an address to a network interface and/or configure network interface parameters. Bruce says that ifconfig has grown increasingly large and become unwieldy. Part of the effort has been to get a handle on all of the options that are currently supported so he has written a YACC grammar for it. He has uploaded some grammer, created a design document and also generated a PDF file you can view which shows you syntax diagrams for each part of the parse tree."