REGEX and Livecode

Peter Alcibiades palcibiades-first at yahoo.co.uk
Wed Jan 2 03:20:44 EST 2013


Its a Linux thing.  Linux is packaged up out of a huge number of components
into actual systems known as 'distributions'.  There are probably around
10-15 major distributions, and around 350 in total.  A great many
distributions are remixes of major ones for some specific purpose.  Ubuntu
is a distribution which originally was a Debian remix.  Other major ones
would be Fedora, Suse, Debian, Slackware.  Distrowatch.com carries a
complete listing.

The way a package gets into a distribution is that it has 'maintainers'.  So
they will take the source code and produce a Debian or Ubuntu package which
the core team then accepts for a given release.

When they do that, it goes into the repositories, which are online archives
of all the packages.  I don't know about Ubuntu, but Debian probably has
some 20-30,000 packages in its repositories.

When you install a package, its not normally a case of get a file and
install it.  You use a package manager, of which there are four or five
variants.  The usual one for Debian and Ubuntu is Synaptic, but there are
others.  Think of them as clients.   

One way to categorize distributions is by how packages are managed.  So you
have the 'apt' ones, of which Debian and Ubuntu are examples.  'rpm' derives
from Red Hat and Suse and Fedora use it.  If it helps, think of this a bit
like email.  Synaptic would be an email client, and there are others.  The
underlying system would be a bit like pop3 or some other mail service
prototcol.  

You find the package in your package manager and tell it to do the
installation.  The package manager then finds all the stuff that it needs
(so called 'dependencies') and installs them too, and it normally takes care
of putting in menu entries and so on.

You can also manually install packages - in the case of Debian and Ubuntu
these will be so called '.deb' packages.  And you can get the source code
and compile and install it.  If you do this, you have to take care of
dependencies yourself, which can be tedious, and this is why package
managers were developed.

So that's what a repository is.  The reason regex is a bit different in the
Linux world, which would include Macs, these being derived from Unix, is
that they are built into the command line utilties.  That's the essence of
Linux at a sophisticated user level.  Of course, you can, and many people
do, use it just like Windows or OSX, in which case its just a vehicle to
your applications and files via a graphical interface, and you don't even
have to realise that there are many different possible desktop environments,
login managers and so on.

The real point of Linux however in terms of features is the shell, and the
thing about this is that regex is like the air in the shell.  Its all around
and being used all the time, and is accessible from anywhere.  Any Linux
editor will support them.  Geany is what I use, but Kate is another.  This
is why I suggested awk to Richmond.  Awk and Sed are old fashioned text
manipulation utilties which are built into all Linux distributions - and
txt2regex and regexxer are going to be in almost all the major repositories. 
If you need to hack around with text, the easiest and quickest way is to use
the tools that have evolved to do it.  They've evolved over 30+years in the
hands of very bright and impatient people who just wanted to get certain
jobs done as simply and quickly as possible, so they are really
sophisticated and powerful.

Nothing wrong with LiveCode, it does text excellently, but it depends what
you are doing and whether you want to just use a command on a file, or
actually write a program.  The commands and the way they can be made to
interact are just very quick, powerful and flexible ways of doing stuff with
text, and after the initial learning curve, they are almost instant.  

A bit longer than I had meant.  If you want to try a distribution, get the
xfce version of PCLinuxOS to start.  But Debian is where you will end up.



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