Hi.
Apologies to jump in here with such a lengthy post.
And I heartily agree with that.
However, that 700-page tome might not be the best place for shell scripting practices. If one is interested in shell programming, the following books are some that we discussed in classes that I lead, and that I have in my library (and there are other, newer books, as well):
Best wishes ... cheers, drl
Title: Classic Shell Scripting
Subtitle: Hidden Commands that Unlock the Power of Unix
Author: A Robbins, N Beebe
First Edition: May 2005
Publisher: O'Reilly
ISBN 10: 0-596-00595-4
Pages: 558
Categories: scripting, shell, programming
Comments: 4.5 stars, 37 reviews Amazon (2015.08)
Title: UNIX(R) Shells by Example
Subtitle: ... guide to the C, Bourne, and Korn Shells plus Awk, Sed, and Grep
Author: Ellie Quigley
Edition: 4th
Date: 2004
Publisher: Prentice-Hall
ISBN: 013147572X
Pages: 1200
Categories: sh, csh, ksh, grep, sed, awk, scripting, shell, programming
Comments: 4.5 stars, 45 reviews Amazon (2007.07)
Comments: ( I have 2nd Ed, 1997 )
Comments: ( 4th edition includes bash and tcsh chapters )
Title: The Art of UNIX Programming
Author: Eric S Raymond
Edition: first
Date: 2003
Publisher: Addison-Wesley Professional
ISBN: 0131429019
Pages: 512
Categories: design, history, unix, linux, programming, development wisdom
Comments: History, principles, guidelines.
Comments: 4 stars (32 reviews, Amazon 2007.11)
Comments: HTML version at http://catb.org/esr/writings/taoup/
Title: Learning the bash Shell
Author: Cameron Newham
Edition: Third
Date: 2005
Publisher: O'Reilly
ISBN: 0596009658
Pages: 376
Categories: bash, scripting, unix, linux, shell, programming
Comments: 4.1 stars, 39 reviews (Amazon 2015.08)
Comments: ( I have 2nd edition, 1998 )
Comments: "bashdb", bash debugger, Chapter 9.
Title: Unix Programming Environment
Author: Brian W. Kernighan, Rob Pike
Edition:
Date: 1984
Publisher: Prentice Hall
ISBN: 013937681X
Pages: 357
Categories: programming, development, software engineering
Comments: 4.5 stars (64 reviews, 2017.09) at Amazon
Title: bash Cookbook
Subtitle: Solutions and Examples for bash Users
Author: Carl Albing, JP Vossen, Cameron Newham
Edition: 1st
Date: 2007
Publisher: O'Reilly
ISBN: 0596526784
Pages: 622
Categories: bash, scripting, unix, linux, shell, programming
Comments: 4.3 stars Amazon (28 reviews, 2015.08)
Note that The Art of UNIX Programming can be read on-line. For example, this chapter: Taxonomy of Unix IPC Methods
Stevens' book is available in Kindle format.
The bash Cookbook was co-written by a Cray employee with whom I worked and coincidently lives nearby.
The Unix Programming Environment is still in print, even after 30 years !
( Edit 1: correct minor grammar error. )