This appendix discusses several of the external software packages discussed throughout the book. Because this is primarily a Cisco book, and we have not focused on any particular software products, this section is restricted to freely distributed software. There are also commercial products that fulfill the same functions as some of these packages (particularly for SNMP) that you may prefer to use.
According to the Perl web site:
Perl is a high-level programming language with an eclectic heritage written by Larry Wall and a cast of thousands. It derives from the ubiquitous C programming language and to a lesser extent from sed, awk, the Unix shell, and at least a dozen other tools and languages. Perl’s process, file, and text manipulation facilities make it particularly well-suited for tasks involving quick prototyping, system utilities, software tools, system management tasks, database access, graphical programming, networking, and world wide web programming.
Many of the scripts written in Perl these days tend to involve dynamically generating web pages. But all of the scripts in this book use Perl at the command line of either a Unix or Windows computer.
We frequently use Perl for scripting network administration functions because it is an extremely powerful and flexible language, particularly for requirements involving pattern matching. This makes it perfect for scanning log files, as well as for spawning dynamic queries and formatting ...