Essential System Administration, Third Edition
by AEleen Frisch 

The unconfirmed error reports are from readers.  They have not yet been 
approved or disproved by the author or editor and represent solely the
opinion of the reader.

Here's a key to the markup:
        [page-number]: serious technical mistake
        {page-number}: minor technical mistake
        <page-number>: important language/formatting problem
        (page-number): language change or minor formatting problem
        ?page-number?: reader question or request for clarification

This page was updated June 20, 2008.


UNCONFIRMED  errors and comments from readers: 


(xiii)  tip;
http://perso.wanadoo.fr/levenez/unix/
has moved to
http://www.levenez.com/unix/


[4]  2nd paragraph;
As printed, the sample command is:

# kill -9 `ps aux | awk '$1=="chavez" {print $2}'

Executing this command yields an error message that refers to an unmatched quote.

Add a matching grave to the end of the command:

# kill -9 `ps aux | awk '$1=="chavez" {print $2}'`

Executing this command kills the processes.

Assuming command substitution is valid in this context, is the second version
correct? Am I missing something just a bit too subtle or advanced for a newbie?


{11}  example at the top of the page;
I think there is still a mistake in the example for /etc/sudoers (section user
specifications).

In order for a user to be able to sudo all the executables of a directory, this
directory must be written with a '/' at the end.

The last line of the example becomes thus :

BACKUPOPS    ALL , !CHEM = BACKUP , /usr/local/bin/

(perhaps this varies depending on the version of sudo).


{31}Paragraph that precedes the sentence "Here is an example command...";
The sentence "By default, searches are not case sensitive, but you can use -g to make them so." is incorrect.

I don't know that plod has a default search mode. Also, the "-g" option makes the search case-INsensitive.


{76}  3nd Paragraph;
Setting up man -k

page shows Solaris command as:

#makewhat /usr/share/man   Solaris

Should be

#makewhatis /usr/share/man  <-- this works on Solaris 8


(161)  last line on page 161;
the "-" between "run" and "level" is missing, the correct output from "who -r" should be:
. run-level 2 Mar 14 11:14 2 0 S
this way, $8 = "0", and $9 = "S"



{183}  Second line;
The top item is not an RG-11 coax connector, it's an AUI connector, I think ... not
directly related to coax cabling.


[196]  bottom paragraph;
In the bottom paragraph on p.196, the book states: "For example, for the network
address 192.168.0.0, you could use only 4 bits for the subnet part rather than the
usual 8, yielding 16 subnets of up to 1022 hosts each."  Have you have mistated the
number of hosts in this example?  If you have 16 subnets, shouldn't you have 4094
hosts on each subnet, because you have 12 bits available for hosts?
See generally www.murchison.net/techno/tcpip/super-chart.html. Your answer of 1022 is
based on 10 bits, which is not given in the example.


[203]  4th paragraph;
The if referred to in this paragraph "en0" should be the same as in the example which
is "eth0". I guess that someone confused the AIX with the Linux device designation.


{263}  Table 6-7, second attribute;
Primary group attribute
"prgp"
should be: 
"pgrp"


{308}  2nd paragraph under "pam_listfile(auth)";
The example for the paragraph states:
"auth required pam_listfile.so onerr=fail sense=deny \
          file=/etc/ftpusers item=user"

The following paragraph says "This entry says that the file /etc/ftpusers (file
argument) contains a list of usernames (item=user)  who should be denied access to
ftp (sense=allow)."

I believe that should say "... who should be denied access to ftp (sense=deny)."  As
the paragraph continues to state "If you want to grant access to a list of users, use
the option sense=allow."


[317]  Example LDIF file at bottom of page;
The line "dc: ahania.com"  appears to be incorrect.  This value does not work for my
server (openldap-2.1.30 on Redhat GNU/LINUX 2.4.18-27.8.0smp).

When I try this I get the following error:
adding new entry "dc=ahania,dc=com"
ldapadd: update failed: dc=ahania,dc=com
ldap_add: Naming violation (64)
        additional info: value of naming attribute 'dc' is not present in entry

=======
It only works if I make the dc: line :

dc: ahania

Thus matching the first domain component value in the dn: line :

dn: dc=ahania,dc=com



{429}  second code example;
@ SOA IN should be @ IN SOA. The Linux DNS HOWTO says so, other books says
so and the error messages on my FreeBSD box say so as well...


[437]  2nd paragraph (first code example);
In the example shown, shouldn't there be an open bracket "{" after the word "options"?


(481)  Packet Sniffers -- second paragraph;
Second word in second paragraph under the Packer Sniffer heading should be free
instead of freel.


{546}  Table 9-3 / syslog mail facility messages;
For the "syslog mail facility messages", /var/adm/maillog is listed for FreeBSD.

FreeBSD does not have /var/adm, like Solaris or Tru64 Unix... instead, all syslog
messages that fall under mail.info get placed under /var/mail/maillog.


[588]  ldap configuration example;
alias_maps = ldap:ldapsource
ldapaliases_server_host ....
ldapaliases_search_base ....

-> should be
ldapsource_server_host ....
ldapsource_search_base ....
etc


{591} 1st line of last paragraph;

The class is called "non_unknown" while It is spelt "no_unknown" everywhere else.


{692}  2nd paragraph from the bottom;
On Solaris, the option to specify filesystem type for mount is -F (this is the case
for Solaris 8 and 9, at least).  In addition, the logical device files for block
devices are located in /dev/dsk.  So the example for Solaris should be something
like:
   mount -o ro -F hsfs /dev/dsk/c0t2d0s0 /mnt


{724}  Table 11-2, Tru64 section;
The Tru64 tape devices are listed as:
/dev/[n]rmt/tapen_dm

However, shouldn't it be something like this for Tru64 v5.x:
/dev/[n]tape/tapen_dm


{901}  2nd code segment;
I don't think this script exits with an '-h' flag, as the 'usage' on p. 900
indicates.

If that behavior is intended, you'd want something like:

elsif ($arg eq 'h') { &usage('') && exit; }



[906]  2nd code segment, 5th line;
print $sep if $matched2 && $nbef > $before && $show_sep && $show_fname;

should read

print $sep if $matched2 && $nbef > $before && $show_sep;