bash Pocket Reference

Many Unix, Linux, and Mac OS X geeks enjoy using the powerful, platform-agnostic text editors vi and Vim, but there are far too many commands for anyone to remember. Author Arnold Robbins has chosen the most valuable commands for vi, Vim, and vi's main clones—vile, elvis, and nvi—and packed them into this easy-to-browse pocket reference. You'll find commands for all kinds of editing tasks, such as programming, modifying system files, and writing and marking up articles.

This second edition includes:

• Command-line options
• vi commands and set options
• Input mode shortcuts
• Substitution and regular expressions
• ex commands and options
• Initialization and recovery
• Enhanced tags and tag stacks
• A greatly expanded section on Vim commands and options
• Additional features in vile, elvis, and nvi
• Internet resources for vi
• A full index

Firewalls, Network Address Translation (NAT), network logging and accounting are all provided by Linux's Netfilter system, also known by the name of the command used to administer it, iptables. The iptables interface is the most sophisticated ever offered on Linux and makes Linux an extremely flexible system for any kind of network filtering you might do. Large sets of filtering rules can be grouped in ways that makes it easy to test them and turn them on and off.

Do you watch for all types of ICMP traffic--some of them quite dangerous? Can you take advantage of stateful filtering to simplify the management of TCP connections? Would you like to track how much traffic of various types you get?

This pocket reference will help you at those critical moments when someone asks you to open or close a port in a hurry, either to enable some important traffic or to block an attack. The book will keep the subtle syntax straight and help you remember all the values you have to enter in order to be as secure as possible. The book has an introductory section that describes applications,followed by a reference/encyclopaedic section with all the matches and targets arranged alphabetically.

Shell scripting skills never go out of style. It's the shell that unlocks the real potential of Unix. Shell scripting is essential for Unix users and system administrators-a way to quickly harness and customize the full power of any Unix system. With shell scripts, you can combine the fundamental Unix text and file processing commands to crunch data and automate repetitive tasks. But beneath this simple promise lies a treacherous ocean of variations in Unix commands and standards. Classic Shell Scripting is written to help you reliably navigate these tricky waters.

Writing shell scripts requires more than just a knowledge of the shell language, it also requires familiarity with the individual Unix programs: why each one is there, how to use them by themselves, and in combination with the other programs. The authors are intimately familiar with the tips and tricks that can be used to create excellent scripts, as well as the traps that can make your best effort a bad shell script. With Classic Shell Scripting you'll avoid hours of wasted effort. You'll learn not only write useful shell scripts, but how to do it properly and portably.

The ability to program and customize the shell quickly, reliably, and portably to get the best out of any individual system is an important skill for anyone operating and maintaining Unix or Linux systems. Classic Shell Scripting gives you everything you need to master these essential skills.