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: <7900001@hpuamsa.UUCP>
Date: 5 Jul 90 08:44:34 GMT
References: <1158@gufalet.let.rug.nl>
Organization: HP The Netherlands (Aka Holland)
Lines: 55

Hallo,

I have piece of code and I remember to have it working.
(But it may have been beginner's luck ?!)

TYPE
   PATHNAME = PACKED ARRAY [1..50] OF CHAR;
...
FUNCTION open
   VAR path : PATHNAME;
       oflag: INTEGER);
   INTEGER:
   EXTERNAL;

...
BEGIN
   path = '/dev/hpib9';
   path[11] = CHR(0);        { The C-open expects that a string
			       is terminated with character zero! }
   eid = open( path, 2);     { 2 = O_RDWR; look also in
			       /usr/include/stdio.h }


Another possible solution that will works:

FUNCTION $ ALIAS 'open' $ dopen
   VAR path : PATHNAME;
       oflag: INTEGER);
   INTEGER:
   EXTERNAL;

and dopen() is in a so called onionskin, this is a little C-program:

dopen( path, oflag)
char *path;
int oflag;
{
   int eid;
   if( (eid = open( path, oflag)) == -1) {
      perror( "Problem ");
      exit( 1);
   }
   return( eid);
}

Compile the C program as follows:
   cc -c cprog.c

The result is an object file called cprog.o

Now do:
   pc -o pprog pprog.p cprog.o

Good luck,
Ton 't Lam,