There've been some big changes in UNIX since we wrote the first
edition in the early 1990s.
We've made this second edition ready for the late 1990s-and, if we guessed
right, for the start of the next century.
Almost 550 of the more than 800 original articles were revised:
many got small edits, but quite a few were completely rewritten.
We included literally hundreds of reader suggestions and corrections.
The CD-ROM has updated scripts and files, as well as binaries for
today's UNIX platforms (including Linux).
The biggest changes were:
The original split between the System V and BSD flavors of
UNIX is still apparent, but it's less important.
We've slanted the blend of options and commands more toward the POSIX
utilities, including the GNU versions (which are close to POSIX
now, but with other features too).
are much more common now than the
footnotes we gave them before.
seems to have combined the superior Bourne shell
programmability with handy
interactive features (and more!),
we've given it more new coverage than
But there's plenty for
the first edition was very strong in
, and almost
everything you'll read about
applies directly to
Overall, we've kept the first edition's emphasis on the core concepts of
that will help you use all UNIX shells.
The separate chapter on
is gone; Perl is much more important
Some of the original articles, including the handy nine-page
have been merged into other chapters.
The short chapter on passwords and security is also history now.
Just as the book we adapted it from (
Practical UNIX and Internet
) has almost doubled in size, the topic is too important these
days for the short coverage we gave it before.
As we did with Perl in both editions, we've left much of the security
information for other books to cover in depth.
(We've still got plenty of cool tips on filesystems and access