2.10. Document Conventions

System manual pages are referenced in the format name(number), where number is the section number of the manual. The pointer value that means ``does not point anywhere'' is called NULL; C compilers will convert the integer 0 to the value NULL in most circumstances where a pointer is needed, but note that nothing in the C standard requires that NULL actually be implemented by a series of all-zero bits. C and C++ treat the character '\0' (ASCII 0) specially, and this value is referred to as NIL in this book (this is usually called ``NUL'', but ``NUL'' and ``NULL'' sound identical). Function and method names always use the correct case, even if that means that some sentences must begin with a lower case letter. I use the term ``Unix-like'' to mean Unix, Linux, or other systems whose underlying models are very similar to Unix; I can't say POSIX, because there are systems such as Windows 2000 that implement portions of POSIX yet have vastly different security models.

An attacker is called an ``attacker'', ``cracker'', or ``adversary''. Some journalists use the word ``hacker'' instead of ``attacker''; this book avoids this (mis)use, because many Linux and Unix developers refer to themselves as ``hackers'' in the traditional non-evil sense of the term. That is, to many Linux and Unix developers, the term ``hacker'' continues to mean simply an expert or enthusiast, particularly regarding computers.

This book uses the ``new'' or ``logical'' quoting system, instead of the traditional American quoting system: quoted information does not include any trailing punctuation if the punctuation is not part of the material being quoted. While this may cause a minor loss of typographical beauty, the traditional American system causes extraneous characters to be placed inside the quotes. These extraneous characters have no effect on prose but can be disastrous in code or computer commands. I use standard American (not British) spelling; I've yet to meet an English speaker on any continent who has trouble with this.