"2. Learning the Vi and Vim Editors, by Arnold Robbins.
I'm a command-line junkie. So, naturally I'm a huge fan of Vi and
Vim editors. Several years back, when I wrote lot of C code on
Linux, I used to carry the Vi editor pocket reference with me all
the times. Even if you've been using Vi and Vim Editors for several
years and have not read this book, please do yourself a favor and
read this book. You'll be amazed with the capabilities of Vim
editor.
"3. Bash Cookbook, by Carl Albing, JP Vossen and Cameron Newham.
Whether you are a sysadmin, DBA or a developer, you have to write
shell script at some point. A wise sysadmin knows that once you've
mastered the shell-scripting techniques, you can put your servers
on auto-pilot mode by letting the shell-scripts do the grunt work.
To get to the auto-pilot mode of sysadmin, you definitely need to
master the examples provided in this cookbook. There are quiet few
Bash shell books out there. But, this books tops them all by giving
lot of detailed examples"