Linux CLI Filter: Complete Linux Command Line Book?

Commands only differ by shell when it comes to http://www.gnu.org/software/bash/manual/html_node/Bash-Builtins.html (and scripting of course). Everything else we call a "command" is just a program installed on the computer, which varies extremely widely by OS, distribution and machine, but not really by shell. Obviously there are commands that exist on the vast majority of Linux machines, and I'm sure that's what you're asking for (in which I think the Nutshell book is probably pretty good), but keep in mind there's no true "complete" list of commands.

Not sure how complete it needs to be for you, but http://shop.oreilly.com/product/9780596154493.do is plenty detailed for me.

http://rute.2038bug.com/index.html.gz is a bit old, but I remember it being... thorough.

Most available linux commands are non-shell executables (e.g. grep, awk, sed, etc.). These can be reviewed in any decent Linux book, but will switch focus based on what you want to do (developer/user, network admin, web server admin, etc.). If you want to get more in depth on bash-only builtins and how the shell works try the http://www.tldp.org/LDP/Bash-Beginners-Guide/Bash-Beginners-Guide.pdf (pdf). I'd say this is much more valuable in the long term than knowing every flag for grep.

Yuck, that double spacing is nasty. Sorry.

For what it is worth, every shell has built in commands, but I find that much of what I do at the command line involves separate programs. How many shells do you actually care about? Maybe for a start, print out the man pages for the shells you are most interested in. This would be an opportunity to learn about unix text formatting conventions. Man pages are typically distributed in some sort of marked up version that then gets formatted for screen or other output. You will have to go elsewhere to find a list of useful command line utilities, but you could write a little shell script to go through that list and make PDFs of those for printing too. Also, if you don't know it already: "man -k" does a keyword search of man pages which can be useful for finding commands to help with given task.

One more thing, from a shell 'echo $PATH' will give you a list of the directories search when you try and execute a command from the command line. If you ls each of those directories you will get a pretty comprehensive list of every command on your system, most of which will have man pages.

Linux in a Nutshell is good enough. There used to be a book of every single man page of every command that a Linux distro might conceivably have. It was impractically large, and I haven't seen a copy for sale in 15 years, so would be almost uselessly out of date.

I know you are looking for something in dead tree format, but keep in mind info is usually more extensive than the man pages. On my system info bash brings up The GNU Bash Reference Manual, if you absolutely must have a book the good people in the GNU project will probably be able to sell or otherwise provide a nicely formatted print edition.