Errata

The example paragraph states that modules for "filesystem (vfat, fat), networking (3c59x)" are shown. But the example output contains nothing of them, only some sound modules are listed.

Note from the Author or Editor:
Please change the text under 'Example' on page 15 to read:

Here, lsmod shows that quite a few kernel modules are loaded, including filesystem (ext3), networking (e100) and sound (ac97_codec, sound, soundcore) modules, among others:

module configuration directives are now located under /etc/modprobe.d/ or /etc/modprobe.conf

Note from the Author or Editor:
Change the decription for the '-c' option at the top of page 19 to:

Display a complete module configuration, including defaults and directives found in /etc/modules.conf (for 2.4 kernels) or /etc/modprobe.conf (for 2.6 and higher kernels). The -c option is not used with any other options.

15. For distributions that use the Debian package management system, what com-mand will download and update all installed packages to the latest available version?

Others also noticed this. To be more accurate, there is not a correct answer provided. The correct way is "apt-get update && apt-get upgrade". Both commands are needed to update to the "latest avaiable version" and install them.

Note from the Author or Editor:
Please change option c on question 15 on page 218 to:

c. apt-get update && apt-get upgrade

and change the answer to #15 on page 226 to:

c. apt-get update && apt-get upgrade

19. What option(s) to rpm will instruct rpm to run a verification check on all pack-
ages installed on the system?
a. rpm ?verify ?all
b. rpm ?Va
c. rpm ?qa
d. rpm ?check
e. rpm ?c

The answer told us is a and b. But a is not correct. Long options should be preceded with double slash, the answer should be "rpm --verify --all" not "rpm -verify -all".

Note from the Author or Editor:
This is an unfortunate error due to the font that was used. Option a. should look like this:

a. rpm --verify --all

That's 2 dashes before 'verify' and 'all'. Please make sure that in the book it's obvious that there are 2 dashes and not 1.

21. Which file(s) does the bash shell read at login to set environment variables?
a. /etc/bashrc
b. ~/.bashrc
c. ~/.bash_profile
d. All of the above
e. None of the above

The answered provided is d. All of the above. But the correct answer should be c. In choice a and b, bashrc is for interactive shells, while .bash_profile is for login shells. They are different.

And if d is right, a, b, and c can also be right, which causes ambiguous right answers.

Note from the Author or Editor:
Please change question #21 on page 219 to:

21. Which file does the bash shell read at login to set environment variables? Select the best answer.

and change the answer on page 226 to:

21. c. ~/.bash_profile

55. Which directory, according to the Filesystem Hierarchy Standard, is designed to hold essential system binaries?
a. /sbin
b. /bin
c. /usr/bin
d. /opt/bin
e. /usr/local/bin

Answer:

a. /sbin

Incorrect, it should be at least a and b.


http://www.pathname.com/fhs/pub/fhs-2.3.html#PURPOSE16

Per the FHS: Utilities used for system administration (and other root-only commands) are stored in /sbin, /usr/sbin, and /usr/local/sbin. ***/sbin contains binaries essential for booting, restoring, recovering, and/or repairing the system in addition to the binaries in /bin.*** [18] Programs executed after /usr is known to be mounted (when there are no problems) are generally placed into /usr/sbin. Locally-installed system administration programs should be placed into /usr/local/sbin.

Note from the Author or Editor:
Please change question #55 on page 225 to:

55. Which directory, according to the Filesystem Hierarchy Standard, is designed to hold essential system binaries used for system administration purposes?

Question stated that User AND Group had read & write, Everybody had read.

is that not a. 002?

answer b is 022.

Note from the Author or Editor:
You're correct, the answer should have been a. umask 002.

"~/.bashrc This file is executed automatically when bash starts. This includes login, as well as subsequent interactive and noninteractive invocations of bash."

This is wrong. ~/.bashrc is only executed for interactive non-login shell, thou sometimes ~/.bash_profile or ~/.profile may source ~/.bashrc.

Note from the Author or Editor:
Please change the description for .bashrc to:

This file is executed when a non-interactive bash shell starts, i.e. a new terminal window in X. This file is often referred to in the bash interactive scripts, such as ~/.bash_profile.

The description of the "while" loop actually describes the "until" loop.
The description on page 282 of 3rd edition 2010 says:
Execute test-commands (usually a test command), and if the exit status is nonzero (that is, the test fails), perform commands and repeat. Opposite of until.

This is seriously wrong. The while command loops as long as the expression is TRUE. Therefore, the explanation should say:
"Execute test-commands (usually a test command), and if the exit status is *zero* (that is, the test *succeeds*), perform commands and repeat. Opposite of until."


Here is reference link to verify:
http://tldp.org/LDP/Bash-Beginners-Guide/html/sect_09_02.html

Note from the Author or Editor:
You're right, we got these reversed. Please change the 'Description' at the top of page 282 to:

Execute test-commands (usually a test command), and if the exit status is zero (that is, the test succeeded), perform commands and repeat. Opposite of until.

Question 36: What is the system-wide bash configuration file called? Include the entire path.

The answer provided on page 474 is /etc/profile.I think this is not very accurate. /etc/profile is "system-wide .profile file for the Bourne shell (sh(1)) and Bourne compatible shells (bash(1), ksh(1), ash(1), ...)." as in /etc/profile comments.

Profile file is not equal to configuration file, they are only for login shells. On the other hand, /etc/bash.bashrc is system-wide .bashrc file for bash.

The question should specify whether for login shell or intercative shell.

Note from the Author or Editor:
You're right, this answer is incomplete, and it really doesn't have to do with interactive shells or not, because (for example) the /etc/bashrc on my Fedora 14 box has tests to see if it's running under an interactive shell.
Also, the Bash Beginner's Guide at TLDP.org mentions both files and makes little distinction between them, other than that non-bash shells might also use /etc/profile while only bash uses /etc/bashrc. http://tldp.org/LDP/Bash-Beginners-Guide/html/sect_03_01.html

If we're to leave the question mostly alone, then the answer needs to be changed to include both files. Please change question #36 on page 472 to:

36. What are the names of the two system-wide bash configuration files? Include the full path for both.

and change the answer on page 474 to:

36. /etc/profile and /etc/bashrc