HP 3000 Manuals

HP Pascal/iX Programmer's Guide

How To Do Pascal I/O with a Non-Pascal Outer Block 

Normally, the outer block of a Pascal program allocates space for the
default text files stdin, stdout, and stderr.  The outer block allocates
space even if these files are referenced through Pascal modules (see
Appendix A  and Appendix B ).  The outer block also opens these
standard files.

In addition, the outer block performs initialization for trap handling
for TRY_RECOVER and for the standard Pascal module arg.

If the outer block is non-Pascal, the following routine can be used to
allocate space, open the default files, and initialize trap handling and
the module arg.

Example 

To compile on MPE/iX, on the command line type:

     pasxl initstuf,,$null;info="set 'hpux=false'"

To compile on HP-UX, on the command line type:

     pc -c -Dhpux=true init_stuff.p

The file (initstuf on MPE/iX or init_stuff.p on HP-UX) is as follows:

     { how to have a non-pascal outer block and still do pascal i/o }
     $if 'hpux'$
     { pascal doesn't buffer these files, uses hp-ux system calls }
     { also initialize the data for the module arg, and so that
       the names on the command line are used for file opens. }
     $endif$

     $global; subprogram$   { allocates text files }
     $literal_alias on$
     program dick(input,output
     $if 'hpux'$  ,stderr $endif$ );
     $if 'hpux'$
     type argtype = packed array[1..32000] of char;
          argarray= array[0..32000] of ^argtype;
          argarrayptr = ^argarray;
     var argc $alias '__argc_value'$ : integer;
         argv $alias '__argv_value'$ : argarrayptr;
         env  $alias '_environ'$ : argarrayptr;

     procedure p_init_args $alias 'P_INIT_ARGS'$(c:integer;
                                                 v,e:argarrayptr); external;
     $endif$
     procedure u_init_traps $alias 'U_INIT_TRAPS'$; external;

     (Example continued on next page.)

     procedure initialize_pascal_standard_files;
     begin
     $if 'hpux'$
     p_init_args(argc,argv,env);          { initialize for module arg }
     $endif$
     u_init_traps;                        { initialize for trap handling }

     { now open standard files }
     reset(input,'$stdin','shared');
     rewrite(output,'$stdlist');
     $if 'hpux'$
     rewrite(stderr,'$stderr');
     $endif$
     end;
     begin end.

MPE/iX 5.0 Documentation