Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!yale!mintaka!bloom-beacon!eru!luth!sunic!mcsun!hp4nl!hpuamsa!ton
From: ton@hpuamsa.UUCP (Ton 't Lam AEO)
Newsgroups: comp.lang.pascal
Subject: Re: Unix system call `open' from HP-Pascal; how?
Message-ID: <7900002@hpuamsa.UUCP>
Date: 5 Jul 90 10:02:19 GMT
References: <1158@gufalet.let.rug.nl>
Organization: HP The Netherlands (Aka Holland)
Lines: 74

I made a little typo.

I said:
  FUNCTION open
     ( VAR path : PATHNAME;
	   oflag: INTEGER);   
       INTEGER:
       EXTERNAL;

This must be:
  FUNCTION open
     ( VAR path : PATHNAME;
	   oflag: INTEGER):  <---   
       INTEGER;   <---
       EXTERNAL;

I exchanged the : and ;

By the way thinking it over you don't need an unionskin.

$sysprog on$
$underscore on$
program tryit( input, output);

const
   O_RDWR   = 2;
   O_WRONLY = 1;

type
   pathname = packed array[1..81] of char;
   cstring  = packed array[1..81] of char;

var
   eid            : integer;
   err ['_errno'] : integer;
   path           : pathname;
   str            : cstring;
   len            : integer;


function $ ALIAS 'open' $ dopen
		 (var path  : pathname;
		      oflag : integer) : integer ; external;

function $ ALIAS 'close' $ dclose
		 (       fd : integer) : integer ; external;

function $ ALIAS 'write' $ send  
		 (       fd : integer;
		  var buffer: cstring;
		      nbyte : integer)           ; external;

begin
   path     = 'filename';
   path[9]  = chr(0);
   eid      = dopen( path, O_RDWR);
   if eid = -1 then
   begin
      writeln( 'Err: ', err');
      halt;
   end;
   cstring  = 'Just a sentence' + chr( 0);
   len      = strlen( cstring);
   write( eid, cstring, len);   { something like this }
   dclose( eid);
end.

This will do. You may want to look in the UNIX reference manual
at create(2), open(2), read(2), close(2). 

Please give a little reply, if it went fine.

Regards,
Ton 't Lam.