In this sentence:

A interactive command, running 'inside' a tty ,...

I suggest that there be an xref link for the word 'tty'. It has not been defined yet,
I think, and it's an important concept.

In this sentence:

"But there's a catch: the Mac uses a carriage return ASCII character 015 to mark the
end of each line,while Unix uses a linefeed (ASCII 012)."

The phrase "ASCII 015" should be in parentheses.

(12 (and others?)) command-line examples;
The Preface shows that this book uses both constant-width Italic and boldfaced
constant-width Italic in examples. If I understand the convention, then the user
input in the examples on this page (the filenames file.mac, file.unix, file1, file2,
file3) should be boldfaced.

There may be other cases of the same problem in articles taken directly from the
second edition. I don't think we used boldfaced constant-width italic in UPT2. So I
won't report every occurrence of this problem... but you might want to search for it.

delete 'are' i.e., so it reads 'file, but not actually'

It should be "/usr/mike" instead of "/u/mike" in "It typically has a name like
/u/mike or /home/mike."

The paragraph starts:

"Though Darwin doesn't come with X Windows, ..."

The rules may have changed. But, when the X Window System came out (and since then,
in the ORA X books too?), it was written clearly somewhere (in the X documentation, I
think) that the system is *not* to be called "X Windows". It's to be called "X" or
"the X Window System".

You might want to check this yourself and, if it's true, check the rest of the book.
(One place to start your check might be http://www.x.org/X11.htm. Also try typing
"man x" or "man X" on Unix systems.) I won't report this again (if I remember not
to, at least :).

In the following section, if the ampersand (&) appears in the printed book, it
probably shouldn't:

"&...

Stands for text (usually computer output) that's been omitted for clarity or to save
space."

I'm not sure if this is an error, but it might be. In the list of author
acknowledgements, the last name is "Jay Ts". I wonder if that should be something
else, like "Jay Tso"? You might want to check.

"man" should be in Italics

has *two* authors. Maybe this needs to be changed to "What we
mean is:".

If you agree, then other articles (many others in chapter 3, for
instance) may also need that change. But each change needs to
be considered on its own: for instance, "my .cshrc file" may not
make sense written as "our .cshrc file".

special-prompt characters" are? Maybe "backslashed prompt
characters" or "backslashed sequences" would be better. The
shell's manual pages probably have a term for these. (Sorry, I
don't have access to any manpages right now.)

Acrobat Reader, at least) it doesn't seem to need two lines.
Also, should "Than" be capitalized? (My grammer aint great... :)

dirs in Your Prompt: Better
Than $cwd

typeface. I am not sure this fits the font conventions listed in
the Preface; should it look like other key combinations (CTRL-d,
etc.)?

Also, the sentence starting with "It also helps to stop 'burn-in' damage" is not clear. "It"
should be replaced with "The clear
command" or simply "clear" (in Italics). This will make it
obvious that "It" doesn't refer to the Mac's command-k command.

Reader, at least). They will work as shown, but the two "true"
values should probably be aligned.

to "interpretation".

use, but doesn't say what it is! (If I remember right, it is a
good way to tell that "there is activity in this terminal" -- while
you're monitoring a build in progress, for instance -- without
using a normal-sized xterm window that clutters the display.)

I believe that book is out of print? Maybe this should refer
to Volume 3M.

too, I think. Maybe this information is still included in
Volume 4M? I don't know.

Last paragraph reads:

"If you have ssh (1.21), its X forwarding..."

Maybe I just missed it in my quick scan through the book... but
it seems like there must be a better cross-reference for ssh
than article 1.21. Chapter 51 doesn't seem to introduce ssh and
its features (like X forwarding); if there isn't an overview of
ssh somewhere else, there should be.

"If you don't see the escape sequences at all,take a look at
Chapter 8 for another way to configure color ls."

This page is part of Chapter 8! How about a more specific
cross-reference?

%ls -li /usr/bin/at
8041 -r-sr-xr-x 4 root wheel 19540 Apr 21 2001 /usr/bin/at*

The "*" at the end of the second line seems to show that this
output is from "ls -liF" instead of "ls -li". The star (*)
should probably be deleted because it doesn't add any useful
information: the mode bits near the start of the line are more
useful.

seems to say that "less" escapes nonprinting characters in the
same way that cat -v and od -c do (in article 12.4). It uses
a different method: highlighting and showing the octal or hex
value (I forget which) in angle-brackets, like <234>. I think
this xref might be changed to read something like:

"...because it escapes nonprinting characters with a method
somewhat like cat -v and od -c (12.4)."

The words "cat -v and od -c" would be greyed in that xref.

Another possible fix would be to make article 12.4 explain
how "less" escapes nonprinting characters.

GNU "spell" utility. Shouldn't this use a globe icon instead,
and have the URL coded into the book's web pages -- so it can
be updated when/if the location changes?

characters. I don't think it should??

"The inner **set** of nested.........in zap pass ..."
change pass to passes (set is a singular noun)

"This happens but not some of the older, more system-specific makes."

A phrase seems to be missing between 'happens' and 'but', or between 'not' and
'some'. I can't deduce what was meant.