Appendix B Dynamic Loading Program Example

This HP Pascal/XL program example illustrates the use of the HPGETPROCPLABEL intrinsic. HPGETPROCPLABEL returns the plabel of the COMMAND intrinsic. The program requests the user to input the name of a CI command. Both the plabel and the CI command are passed to the HP Pascal/XL CALL procedure which calls COMMAND and directs it to execute the user-specified CI command.

$standard_level 'FULL_MODCAL'$ 

   $type_coercion 'NONCOMPATIBLE'$ 

   $tables off$ 

   PROGRAM hpgetprocplabel_test(input, output); 

   

   TYPE 

      c80 = packed array [1..80] of char; 

     mpexl_status = record 

         case integer of 

            0 : (all : integer); 

            1 : (info   : shortint; 

                 subsys : shortint); 

            end; 

      Proc_Type = procedure(VAR command : c80; VAR error, parm : shortint); 

      Proc_Name_Type = string32; 

      File_Name_Type = packed array [1..36] of char; 

      bit32 = minint..maxint; 

   {  bit32 = 0..4294967295; } 

   

   VAR 

      status      : mpexl_status; 

      Proc_Name   : Proc_Name_Type; 

      plabel      : bit32; 

      Invoke_Proc : Proc_Type; 

      command_str : string80; 

      command     : c80; 

      str_cr      : string 1 ; 

      cr          : packed array [1..1] of char; 

      error, parm : shortint; 

      cicat       : shortint; 

      catname     : File_Name_Type; 

   

   PROCEDURE hpgetprocplabel;     INTRINSIC; 

   PROCEDURE fclose;              INTRINSIC; 

   FUNCTION  fopen : shortint;    INTRINSIC; 

   PROCEDURE genmessage;          INTRINSIC; 

   PROCEDURE terminate;           INTRINSIC; 

      

   000  begin 

   001  Proc_Name := ' COMMAND '; 

   002  writeln('About to call hpgetprocplabel'); 

   003 

   004  hpgetprocplabel(Proc_Name, plabel, status); 

   005 

   006  if (status.all <> 0) or 

   007     (ccode <> 2) then 

   008     begin 

   009     writeln('status.subsys:', status.subsys); 

   010     writeln('status.info:  ', status.info); 

   011     end 

   012  else 

   013     begin 

   014     writeln('hpgetprocplabel successfully called'); 

   015     end; 

   016 

   017  Invoke_Proc := Proc_Type(plabel); { coerce 32 bit ptr to 64 bit } 

   018 

   019  prompt('Enter MPE XL Command:'); 

   020  readln(command_str); 

   021  cr 1  := chr(13); 

   022  strmove(1, cr, 1, str_cr, 1); 

   023  strappend(command_str, str_cr); 

   024  strmove(strlen(command_str), command_str, 1, command, 1); 

   025 

   026  CALL(Invoke_Proc, command, error, parm); 

   027 

   028  if error <> 0 then 

   029     begin 

   030     writeln('Error in command:', command); 

   031     catname := 'catalog.pub.sys '; 

   032     cicat   := fopen(catname, 5, octal('420')); 

   033     genmessage(cicat, 2, abs(error)); 

   034     fclose(cicat, 0, 0); 

   035     end; 

   036 

   037  end.

Appendix B Dynamic Loading Program Example

Technical documentation

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