Re:

[Mark . Burgess]

On 16 Mar, Bautista, Teresita wrote:
> Hi Mark,
> 
> Thank you so much for the e-mail.
> However, what does it exactly mean when you say "Declarative Configuration
> Language"?
> 
> Another is that to my understanding, adopting cfengine and implementing this
> means writing scripts.  However, from the website it say it is higher level
> than scripts.  They seems contradicting.
> Please enlighten me.
> 
> Once again, thank you for your advice and time :)
> 
> Kind regards,
> 
> 
> 
> 
> -----Original Message-----
> From: Mark.Burgess@iu.hio.no [mailto:Mark.Burgess@iu.hio.no]
> Sent: 16 March 2001 16:28
> To: Teresita.Bautista@KPNQwest.com
> Cc: help-cfengine@gnu.org
> Subject: Re: 
> 
> 
> On 16 Mar, Bautista, Teresita wrote:
>> Hi,
>> 
>> I am very new with cfengine and would be grateful if someone can advice me
>> on my questions.
>> 
>> Somewhere in the documentation says that cfengine is a high level
> language,
>> higher than perl or scripts.  If so, is cfengine another programming
>> language of its own right?  
>> 
>> Please help :(
>> 
>> thanks in advance.
>> 
>> Kind regards,
>> Teresita
> 
> 
> Cfengine is not a programming language, but a declarative
> configuration language. That means that it can only be used
> for a limited purpose. It is not a general programming language.
> 
> M
> 
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Work: +47 22453272            Email:  Mark.Burgess@iu.hio.no
> Fax : +47 22453205            WWW  :  http://www.iu.hio.no/~mark
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


Normal languages are procedural. That means that they follow logical
sequences or prcoedures as a stream of thought. The sequence has to
lead from the start to the finish and every step must be described.

Declarative languages are descriptive. Instead of specifying steps,
you write a description of what you would like to see. Then this is
interpreted by an agent and the details of how it happens are hidden.

CFengine provides a language for describing how you would like
systems to be configured. Cfengine then interprets this and doesn
the job. This allows you to think about policy, rather than fiddly
details.

you still write "scripts", if you want to call them that, but they
are more like descriptions than procedures,

hope this helps,
Mark

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Work: +47 22453272            Email:  Mark.Burgess@iu.hio.no
Fax : +47 22453205            WWW  :  http://www.iu.hio.no/~mark
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~