The Labs.Com Admin Lab Perl Lab

The Labs - Design & Functionality For The Net

Perl, The Joy of Programming

Perl is surely the most powerful language for the UNIX platform to handle system-adminstration tasks. I nearly write everything in Perl nowadays, even graphic applications, not to mentioned 95% of all my CGIs (exceptions are heavy used CGIs, ie. web-counter, or webchat).

1. Introduction
2. Online Documentation
3. Comprehensive Perl Archive Network (CPAN)
4. Perl & HTML
5. Perl Examples
6. Misc Perl Prgs
7. Perl Compiler
8. Perl
10. Inline

Perl is certainly the best script-language I have encountered, and use it for all purposed. I only use to write C for resource-sensitive applications, I always try to find a way to use Perl.

Perl.Com The main entry-point	use Perl; Perl News service	CPAN.Org Comprehensive Perl Archive Network
PerlTK TK modules

Perl Lab 2. Online Documentation

Perl-Manual 5.005_02 Comprehensive Perl-Manual

Search Manual:

Enter 'faq' to read the Perl-FAQs.

Perl Lab 3. Comprehensive Perl Archive Network (CPAN)

There you find all the modules you likely will use to write your applications:

CPAN.Org Original site

Nearest CPAN Nearest copy of cpan

Search CPAN:

Install Modules

perl -MCPAN -e 'install Time::HiRes'  as example install the HiRes package.

Perl Lab 4. Perl & HTML

Using Perl within HTML isn't really support officially, but there are some more or less consistent approaches worthwhile to consider:

ModPerl The basis . . .	PowerPerl Inline perl using <script language="PerlScript"> tags	Embperl: Embed Perl in HTML Embedded perl within HTML using [- and -] as tags
Mason Very promising embedded perl <% ... %>	ePerl Alike package, uses <? and !> as tags	ProgrammerHTML Handler & Pre-processor
InlinePerlPages Lightweight inline perl

Perl Lab 5. Perl Examples

Best is learning from the experts:

The Perl Journal: Programs Back issues archived by issue & topic

Perl Lab 6. Misc Perl Prgs

Here some of our perl-stuff we did:

SystemViuw Small PerlTK script show cpu/memory and disk-space	NetViuw Small PerlTK script shows netstat	PerlFlash Writing flash .swf via perl
DNSTool Making life easier with bind-4.x and bind-8.x

and more programs, as we use perl almost for everything . . .

Perl Lab 7. Perl Compiler

The long expected is finally here, the perl compiler.

test.pl:

#!/usr/local/bin/perl

print "Hi there!\n";

Byte Code

First level of compiling (as the interpreter usually does) is the byte-code:  perlcc -b test.pl  and you get test.plc, which is machine-independent, executed by perl test.plc.

Compiled

To compile it truly into a binary (via C-source and cc)  perlcc test.pl  and you get test, which is now machine-dependent.

Reversing Byte Code

You can also translate byte-code back to source (great feature!):  perlcc -MO=Deparse test.pl  which creates byte-code and gives out the source-code; great feature to make source-code readable again.

Perl Lab 8. Perl::Inline

The module Inline provides a nifty interface (API) to other compiled or interpreted languages.

Inline::C

The Inline::C allows to include C functions within the perl-source. Inline::C extracts the C-source and compiles the code into binary and is then called with appropriate arguments. Advantage: fast and easy integration of performance sensitive C/C++ code. Disadvantage: code is compiled first (once or when code changes) and binary is cached, may compromise perl-portability. Many Perl5 modules provide interface to existing C/C++ libraries, Inline::C will provide a very fast and handy implementation approach; most useful for prototyping. Example:  use Inline C => <<'END_C';      void greet() {      printf("Hello, world\n");   }   END_C   greet;

Download

Inline & Inline::C Perl language interface Inline::CPR Running C as script (compiles itself if necessary)

It is to be expected more languages will be supported very soon (Jan 2001). We certainly will start to use Inline::C now extensively in our existing perl-programs (e.g. ProgrammerHTML and PicArt) which worked as interface to implement or interface another script- or compiled language.

                                                                                                                                   

Admin Lab

SymMount