OpenEuphoria

2. Re: CHAIN PROGRAM

• Posted by Derek Parnell <ddparnell at bigpond.com> Dec 20, 2006
• 566 views

mark wrote:
> 
> 
> i post a message previously to ask : how to chain eu program

Why do you want to chain programs? This is a technique used by BASIC and COBOL
programs many many years ago to get over the problem that some programs were too
big to fit into memory so they were broken up into stages and the stages were
chained together.

Modern computers have lots of memory so this is very rarely an issue today.

> I find a way to do it but not sure if it loaded more copies of the intepreter
> 
> at the point the program is to "CHAIN"
> 
> the code will be:
> 
> exitcode = system_exec("p2.ex",2)
> 
> it works, but i am not sure if it will exhaust the memory, i.e.
> is the intepreter executing the parent program , executing the seccond 'child'
> program (p2.ex) or another copy of intepreter is loaded?
> The message on the forum on this subject is rather confuding to me
> Sorry I am new at this computer stuff and dont quiet understand the memory
> issue
> 
> I am concerned that the memory is overloaded and the files are corrupted
> thanks

Why not just write 'p2' as an include file and call it from within 'p1'?

-- 
Derek Parnell
Melbourne, Australia
Skype name: derek.j.parnell

4. Re: CHAIN PROGRAM

• Posted by Al Getz <Xaxo at aol.com> Dec 20, 2006
• 584 views

Hi there Mark,

I have chained a number of my Eu programs as well.
I had a few times where it was easier to call a program from
another program and pass data via the command line rather than
rewrite the whole thing.  The 2nd program has to be bound the
way i did it, and the syntax for calling it looks something
like this:
  system("DirectoryName\\Program2.exe data",0)
The data gets passed to the second program this way.

I havent used this very often, but when i needed to do it that
way it worked very well.  The drawback is that you have to bind
p2 first, but with the Eu being open source now that shouldnt be
a problem for anyone.


Take care,
Al

E boa sorte com sua programacao Euphoria!


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"I can live with losing the good fight,
 but i can not live without fighting it".
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6. Re: CHAIN PROGRAM

• Posted by mark <marktio at hotmail.com> Dec 20, 2006
• 538 views

Thank you Al
Really appreciate your help
Have a great Holidays season!

8. Re: CHAIN PROGRAM

• Posted by irv mullins <irvm at ellijay.com> Dec 20, 2006
• 567 views
• Last edited Dec 21, 2006

Mark:

Can you please explain exactly WHY you want to chain one program from another? 
That would make it easier for us to give useful advice.

10. Re: CHAIN PROGRAM

• Posted by Chris Burch <chriscrylex at aol.com> Dec 20, 2006
• 567 views
• Last edited Dec 21, 2006

mark wrote:
> 
> Hi irv
> 
> i am trying to set up a database program
> 
> so the first program is a menu that display several modules, eg
> 1. customer module
>  1.1 customer file maintenance (ie add,delete and update customer info)
>  1.2 customer list
>  .... etc
> 2. product file module
>  2.1 product file maintenance
>  2.2 product list
> 
> the first program is called say p1.ex
> if user enter a selection say 2.2 , the program will execute another 
> program called p2.ex
> if use enter 2.1 the program will execute another program p3.ex
> so there could be 30 to 40 programs that can be run from a menu program
> 
> so how can i code when running p1.ex to go to say any other program, 
> return back to the menu program?
> 
> Thanks for your time and help
> I really appreciate all the kind reply the member has given me!
> Merry Christam and wish you all great holiday season and a healthy New Year

Hi

You really really don't want to do that. Chaining the program will lead to a lot
of duplicated effort

Euphoria can accomodate HUGE programs - what you want to do is fairly trivial
(no derogatory comment / insult intended)

Look at JetvetSQL for an example (in the archives, text mode only).

Hint - start simple with the database, then build on it. Add includes for a new
module. Choose your database before you start, edb, eusql, sqlite, mysql tsunami
etc - all have their pros and cons. Remember to reference the tables to each
other with record ids (usually integers) - see CKs site for a very simple sql
intro.

Chris

http://euallegro.wikispaces.com
http://members.aol.com/chriscrylex/euphoria.htm
http://uboard.proboards32.com/
http://members.aol.com/chriscrylex/EUSQLite/eusql.html

12. Re: Re: CHAIN PROGRAM

• Posted by cchris005 at fastmail.fm Dec 21, 2006
• 568 views
• Last edited Dec 22, 2006

> Subject: Re: CHAIN PROGRAM
> 
> 
> posted by: mark <marktio at hotmail.com>
> 
> Hi irv
> 
> i am trying to set up a database program
> 
> so the first program is a menu that display several modules, eg
> 1. customer module
>  1.1 customer file maintenance (ie add,delete and update customer info)
>  1.2 customer list
>  .... etc
> 2. product file module
>  2.1 product file maintenance
>  2.2 product list
> 
> the first program is called say p1.ex
> if user enter a selection say 2.2 , the program will execute another 
> program called p2.ex
> if use enter 2.1 the program will execute another program p3.ex
> so there could be 30 to 40 programs that can be run from a menu program
> 
> so how can i code when running p1.ex to go to say any other program, 
> return back to the menu program?
> 
> Thanks for your time and help
> I really appreciate all the kind reply the member has given me!
> Merry Christam and wish you all great holiday season and a healthy New
> Year
> 

As someone suggested, just don't chain anything.
I assume you already have programs, say p2_1.ex, p3_14.ex and so on.
Then, at the beginning of the main (menu) program, add a buch of include
statements:

include p2-1.ex as p2_1
--...
include p3_14.ex as p3_14
</endcode>

In each of the programs, lump all top level code that may be executed
several times inside a global routine, say execute(object data).

Now, when your menu program gets a selection from user, it figures out
the data (you already did this if your system works), and then issue
}}}
<eucode>
call_proc(routine_id(prog_name&":execute"),{data})

Use call_func() instead if your programs return anything you may use,
like an error code.

If you programs are used to get their data from the command line, you'll
have to pass data in the format they expect, and to change instances of
command_line() i your programs to data.

This looks like the way to achieve your goal with the less file edition.
Since data can be anything, this may simplify and speed up the code in
your programs that was getting actual data from the command line.

Your program files are still separate, but only one copy of the
intermreter will be running in memory, as you tricked it into thinjing
it executes the same main code (your menu program).

TIA
CChris
-- 
  
  cchris005 at fastmail.fm

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