Path: news.cs.au.dk!not-for-mail
From: "Sascha Kimmel" <kimmel@tricos.com>
Newsgroups: comp.lang.beta
Subject: RE: problems with processes
Date: 27 Feb 1999 22:14:34 -0000
Organization: University of Aarhus, Department of Computer Science (DAIMI)
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Reply-To: "Sascha Kimmel" <kimmel@tricos.com>
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> -----Ursprüngliche Nachricht-----
> Von: Arne Hüggenberg [mailto:zalaster@nef.wh.uni-dortmund.de]
> Gesendet am: Samstag, 27. Februar 1999 20:17
> An: usergroup@mjolner.dk
> Betreff: problems with processes
>
> Hello everyone,
> i have a problem im hoping someone here can me help with
> Using the PE for Linux im trying to do something like this:
> lprtest.bet:

I'm using BETA 4.1 Pro on Win98 the most time, but sometimes also under
Linux, but don't expect too much help for BETA under Linux from me ;-)
But I'll try.

> ORIGIN '~beta/basiclib/current/systemenv';
> INCLUDE 'lpr';
>
> -- program:descriptor --
> systemenv
> (#
> TextToPrint: ^TEXT;
> do
> &text[]->TextToPrint[];
> 'this is a test'->TextToPrint.putline;
> 'wonder if this works'->TextToPrint.putline;

Haven't tried it this way, but it works the same way as 'this is a
test'->TextToPrint.append , or am I totally wrong now?
But doesn't PUTLINE always append a NEWLINE to a text string?

> TextToPrint[]->&lpr_process;

Doesn't TextToPrint[]->lpr_process; do the stuff alone?

> #)
>
>
> with lpr.bet being:
>
> ORIGIN '~beta/basiclib/current/systemenv';
> INCLUDE '~beta/process/current/processmanager';
> -- Systemlib: Attributes --
> lpr_process: Systemenv
>   (#
>      PrintMe: ^TEXT;
>      exec:
>        (# name: ^text; child: @process;
>         enter name[]
>         do
>           name[]->child.init;
>           printme[]->child.RedirectFromChannel;
>           child.start;
>           child.awaitStopped;

Freezes the program until the process has finished.

>          #);
>
>   enter PrintMe[]
>   do 'starting lpr_process'->putline;
>  ('/usr/bin/lpr')->exec;
>   #);
>
>
> now what happens is that an execution of lprtest.bet results in:
>
> arne@darkwing:~/code > ./lprtest
>
> *******************************************************************
> * Note: This program was compiled using a Personal Edition of the *
> * Mjolner BETA System and may not be used for commercial purposes *
> *******************************************************************
>
>
> FORK FAILURE: Only newly created systems may be forked.
>
> # Beta execution aborted: Stop is called.
> # Look at 'lprtest.dump'
>
> with the dump file being
>
> arne@darkwing:~/code > cat lprtest.dump
> Beta execution aborted: Stop is called.
>
> Call chain: (linux)
>
>   item <BETAENVSTOP-~> in ~beta/basiclib/v1.6/private/betaenvbody
>     -- stop# in ~beta/basiclib/v1.6/betaenv
>   item <stop#> in ~beta/basiclib/v1.6/betaenv
>     -- BETAENV-~ in ~beta/basiclib/v1.6/betaenv
>   item <FORKFIRST-~> in ~beta/basiclib/v1.6/private/basicsystemenvbody
>     -- fork# in ~beta/basiclib/v1.6/basicsystemenv
>   item <fork#> in ~beta/basiclib/v1.6/basicsystemenv
>     -- lpr_process#SystemEnv#SysHead# in /home/arne/code/lpr
>   item <init#> in ~beta/basiclib/v1.6/private/basicsystemenvbody
>     -- BASICSYSTEMENVPRIVATE-~ in
> ~beta/basiclib/v1.6/private/basicsystemenvbody
>   item <INITSYSTEMENV-~> in
> ~beta/basiclib/v1.6/private/basicsystemenvbody
>     -- lpr_process#SystemEnv#SysHead# in /home/arne/code/lpr
>   item lpr_process#<SystemEnv#>SysHead# in
> ~beta/basiclib/v1.6/basicsystemenv
>     -- BETAENV-~ in ~beta/basiclib/v1.6/betaenv
>   comp <PROGRAM-~>SystemEnv#SysHead# in /home/arne/code/lprtest
>     -- BETAENV-~ in ~beta/basiclib/v1.6/betaenv
>
>
>   item <attNext#>realValue# in
> ~beta/basiclib/v1.6/private/basicsystemenvbody
>     -- BASICSYSTEMENVPRIVATE-~ in
> ~beta/basiclib/v1.6/private/basicsystemenvbody
>   item <*>cycle# in ~beta/basiclib/v1.6/private/systemenv_unixbody
>     -- BASICSCHEDULER-~ in
> ~beta/basiclib/v1.6/private/systemenv_unixbody
>   comp <BASICSCHEDULER-~> in
> ~beta/basiclib/v1.6/private/systemenv_unixbody
>     -- PROGRAM-~SystemEnv#SysHead# in /home/arne/code/lprtest
>
>
>   basic component in ~beta/basiclib/v1.6/betaenv
>
>
> and im dont quite understand why this doesent work as i expect.
>
>
>
> Also, when putting it all in one file it seems to work fine, except for
> the fact that
>
> PrintMe[]->RedirectFromChannel;
>
> results in :
>
> # Beta execution aborted: Qualification error in reference assignment.
> # Look at 'lpr.dump'

It's obvious that if there's no process to which the string should be
redirected to, there is a little problem.
Try <<PrintMe[]->child.RedirectFromChannel;>>

> trying to be clever i then did
>
> PrintMe[]->qua(# as::< stream #)->RedirectFromChannel;
>
>
> but to no avail, still dumps with the same qualification error in
> reference assignment

See above.

>
>
>
> anyone know what im doing wrong?
>
> any help would be appreciated :-)
>
> Arne Hüggenberg
>

Hope this helps at least a bit :)

Reagrds,
Sascha Kimmel
(kimmel@tricos.com)