The Developer Connection…ice Driver Kit for OS/2 3/DEV3-D1.ISO/docs/rexxapi.inf

OS/2 Help File | 1993-07-30 | 110.4 KB | 4,345 lines

ΓòÉΓòÉΓòÉ 1. How to Use the Program Reference ΓòÉΓòÉΓòÉ

The REXX Program Reference is a detailed technical reference for application
programmers.  It gives reference information and code examples to enable you to
write source code using REXX Program functions.

Before you begin to use this information, it would be helpful to understand how
you can:

o Expand the Contents to see all available topics
o Obtain additional information for a highlighted word or phrase
o Use action bar choices
o Use the programming information.

How to Use the Contents

When the Contents window first appears, some topics have a plus (+) sign beside
them. The plus sign indicates that additional topics are available.

To expand the Contents if you are using a mouse, click on the plus sign.  If
you are using the keyboard, use the Up or Down Arrow key to highlight the
topic, and press the plus (+) key. For example, File System has a plus sign
beside it. To see additional topics for that heading, click on the plus sign or
highlight that topic and press the plus (+) key.

To view a topic, double-click on the topic (or press the Up or Down Arrow key
to highlight the topic, and then press the Enter key).

How to Obtain Additional Information

After you select a topic, the information for that topic appears in a window.
Highlighted words or phrases indicate that additional information is available.
You will notice that certain words and phrases are highlighted in green
letters, or in white letters on a black background.  These are called hypertext
terms. If you are using a mouse, double-click on the highlighted word.  If you
are using a keyboard, press the Tab key to move to the highlighted word, and
then press the Enter key.  Additional information then appears in a window.

How to Use Action Bar Choices

Several choices are available for managing information presented in the OS/2*
2.0 Control Program Reference.  There are three pull-down menus on the action
bar:  the Services menu, the Options menu, and the Help menu.

The actions that are selectable from the Services menu operate on the active
window currently displayed on the screen. These actions include the following:

Bookmark
   Allows you to set a placeholder so you can retrieve information of interest
   to you.

   When you place a bookmark on a topic, it is added to a list of bookmarks you
   have previously set.  You can view the list, and you can remove one or all
   bookmarks from the list.  If you have not set any bookmarks, the list is
   empty.

   To set a bookmark, do the following:

    1. Select a topic from the Contents.

    2. When that topic appears, choose the Bookmark option from the Services
       pull-down.

    3. If you want to change the name used for the bookmark, type the new name
       in the field.

    4. Click on the Place radio button (or press the Up or Down Arrow key to
       select it).

    5. Click on OK (or select it and press Enter). The bookmark is then added
       to the bookmark list.

Search
   Allows you to find occurrences of a word or phrase in the current topic,
   selected topics, or all topics.

   You can specify a word or phrase to be searched.  You can also limit the
   search to a set of topics by first marking the topics in the Contents list.

   To search for a word or phrase in all topics, do the following:

    1. Choose the Search option from the Services pull-down.

    2. Type the word or words to be searched for.

    3. Click on All sections (or press the Up or Down Arrow keys to select it).

    4. Click on Search (or select it and press Enter) to begin the search.

    5. The list of topics where the word or phrase appears is displayed.

Print
   Allows you to print one or more topics.  You can also print a set of topics
   by first marking the topics in the Contents list.

   To print the document Contents list, do the following:

    1. Choose Print from the Services pull-down.

    2. Click on Contents (or press the Up or Down Arrow key to select it).

    3. Click on Print (or select it and press Enter).

    4. The Contents list is printed on your printer.

Copy
   Allows you to copy a topic that you are viewing to the System Clipboard or
   to a file that you can edit. You will find this particularly useful for
   copying syntax definitions and program samples into the application that you
   are developing.

   You can copy a topic that you are viewing in two ways:

   o Copy copies the topic that you are viewing into the System Clipboard.  If
     you are using a Presentation Manager* (PM) editor (for example, the System
     Editor) that copies or cuts (or both) to the System Clipboard, and pastes
     to the System Clipboard, you can easily add the copied information to your
     program source module.

   o Copy to file copies the topic that you are viewing into a temporary file
     named TEXT.TMP.  You can later edit that file by using any editor.  You
     will find TEXT.TMP in the directory where your viewable document resides.

     To copy a topic, do the following:

       1. Expand the Contents list and select a topic.

       2. When the topic appears, choose Copy to file from the Services
          pull-down.

       3. The system puts the text pertaining to that topic into the temporary
          file named TEXT.TMP.

   For information on one of the other choices in the Services pull-down,
   highlight the choice and press the F1 key.

The actions that are selectable from the Options menu allow you to change the
way your Contents list is displayed. To expand the Contents and show all levels
for all topics, choose Expand all from the Options pull-down. You can also
press the Ctrl and * keys together. For information on one of the other choices
in the Options pull-down, highlight the choice and press the F1 key.

The actions that are selectable from the Help menu allow you to select
different types of help information.  You can also press the F1 key for help
information about the Information Presentation Facility (IPF).

How to Use the Programming Information

The REXX Program Reference consists of reference information that provides a
detailed description of each REXX function.

REXX Program programming information is presented by component, such as
Subcommmand Interface Functions, System Exit Functions and Macrospace
Functions, for example:

     ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
     Γöé            Contents                     Γöé
     Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
     Γöé                                         Γöé
     Γöé  + Subcommand Interface Functions       Γöé
     Γöé  + System Exit Functions                Γöé
     Γöé  + Macrospace Functions                 Γöé
     Γöé                                         Γöé
     ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ

By clicking on the plus sign beside 'Subcommand Interface Functions', you see
an alphabetic list of the REXX functions for the subcommand interface.
Selecting a function takes you directly into the reference information for that
function.

Units of reference information are presented in selectable multiple windows or
viewports. A viewport is a Presentation Manager window that can be sized,
moved, minimized, maximized, or closed.  By selecting a unit (in this case, an
entry on the Contents list), you will see two windows displayed:

    ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
    Γöé Unit Title    Γöé   Selection Title           Γöé
    Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
    Γöé Select one:   Γöé                             Γöé
    Γöé    .          Γöé                             Γöé
    Γöé    .          Γöé                             Γöé
    Γöé    .          Γöé                             Γöé
    Γöé Return Values Γöé                             Γöé
    Γöé Errors        Γöé                             Γöé
    Γöé Notes         Γöé                             Γöé
    Γöé               Γöé                             Γöé
    Γöé               Γöé                             Γöé
    ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ

The window on the left is the primary window.  It contains a list of items that
are always available to you.  The window on the right is the secondary window.
It contains a 'snapshot' of the unit information. For reference units (that is,
function descriptions), this window contains the Call Syntax.

All of the information needed to understand a reference unit (or topic) is
readily available to you through the primary window. The information is divided
into discrete information groups, and only the appropriate information group
appears for the topic that you are viewing.

The information groups for a reference unit (that is, a function description)
can include the following:

o Call Syntax
o Uses
o Parameters
o Data Structures
o Return Values
o Errors
o Notes
o Related Functions
o Examples
o Sample Programs

This list may vary.  Uses, Data Structures, Notes, Related Functions, Examples,
and Sample Programs may be omitted when they do not apply. In other instances,
information may be added when appropriate. For example, when viewing the
RexxStart function, you will see the Data Structures topic and the Examples
topic in the primary window.

Information groups are displayed in separate viewports that are stacked in a
third window location that overlaps the secondary window. By selecting an item
(information group) in the primary window, the item is displayed in the third
window location:

  ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
  Γöé Unit Title   Γöé   Selection TiΓöé   Data Types  Γöé
  Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
  Γöé Select one:  Γöé               Γöé  BOOL         Γöé
  Γöé              Γöé               Γöé  BYTE         Γöé
  Γöé    .         Γöé               Γöé  CHAR         Γöé
  Γöé    .         Γöé               Γöé    .          Γöé
  Γöé    .         Γöé               Γöé    .          Γöé
  Γöé Data Types   Γöé               Γöé    .          Γöé
  Γöé Errors       Γöé               Γöé               Γöé
  Γöé              Γöé               Γöé               Γöé
  Γöé              Γöé               Γöé               Γöé
  Γöé              Γöé               Γöé               Γöé
  ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ

By selecting successive items from the primary window, additional windows are
displayed on top of the previous windows displayed in the third window
location.  For example, in a function description, Parameters and Return Values
are items listed in the primary window.  When selected, they appear one on top
of the other in the third window location. Because of this, you may move the
first selected (topmost) window to the left before selecting the next item.
This allows simultaneous display of two related pieces of information from the
'stack' of windows in the third window location:

  ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
  Γöé Unit Title    Γöé  Parameters   Γöé Return Values Γöé
  Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
  Γöé Select one:   Γöé               Γöé  RXSUBCOM_NOERΓöé
  Γöé    .          Γöé               Γöé  RXSUBCOM_NOTRΓöé
  Γöé    .          Γöé               Γöé  RXSUBCOM_NOEMΓöé
  Γöé    .          Γöé               Γöé  RXSUBCOM_BADTΓöé
  Γöé Parameters    Γöé               Γöé    .          Γöé
  Γöé Return Values Γöé               Γöé    .          Γöé
  Γöé Errors        Γöé               Γöé    .          Γöé
  Γöé Examples      Γöé               Γöé               Γöé
  Γöé               Γöé               Γöé               Γöé
  Γöé               Γöé               Γöé               Γöé
  ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ

Each window can be individually closed from its system menu.  All windows are
closed when you close the primary window.

Some secondary windows may have the appearance of a split screen. For example,
an illustration may appear in the left half of the window, and scrollable,
explanatory information may appear in the right half of the window.  Because
illustrations may not necessarily fit into the small window size on your
screen, you may maximize the secondary window for better readability.


ΓòÉΓòÉΓòÉ <hidden> IBM Trademark ΓòÉΓòÉΓòÉ

Trademark of the IBM Corporation.


ΓòÉΓòÉΓòÉ 2. REXX Functions ΓòÉΓòÉΓòÉ

The following functions can interface with the REXX interpreter:

RexxAddMacro
RexxClearMacroSpace
RexxDeregisterExit
RexxDeregisterFunction
RexxDeregisterSubcom
RexxDropMacro
RexxLoadMacroSpace
RexxQueryExit
RexxQueryFunction
RexxQueryMacro
RexxQuerySubcom
RexxRegisterExitExe
RexxRegisterExitDll
RexxRegisterFunctionExe
RexxRegisterFunctionDll
RexxRegisterSubcomExe
RexxRegisterSubcomDll
RexxReorderMacro
RexxResetTrace
RexxSaveMacroSpace
RexxSetHalt
RexxSetTrace
RexxStart
RexxVariablePool


ΓòÉΓòÉΓòÉ 3. Using REXX Interfaces ΓòÉΓòÉΓòÉ

This chapter is addressed mainly to professional systems and application
programmers. It describes:

o RXSTRINGs
o Invoking the REXX Interpreter
o Subcommand Handlers
o External Functions
o System Exits
o Variable Pool Interface
o Macrospace Interface
o Halt and Trace Functions

In this chapter, the term application refers to programs written in languages
other than REXX. The features described here allow an application to extend
many parts of the REXX language or extend an application with REXX. This
includes creating handlers for subcommands, external functions and system
exits.

Subcommands Commands issued from a REXX program. A REXX expression is evaluated
           and the result is passed as a command to the currently "addressed"
           subcommand handler. Subcommands are used in REXX programs running as
           application macros.

Functions  Direct extensions of the REXX language. An application can create
           functions that extend the native REXX function set. Functions may be
           general purpose extensions or specific to an application.

System Exits Create programmer-defined variations of the operating system. The
           application programmer can tailor the REXX interpreter behavior by
           replacing the OS/2* operating system for REXX system requests.

Subcommand, function and exit handlers have similar coding, compilation and
packaging characteristics.

In addition, applications can manipulate the variables in REXX programs (the
Variable Pool Interface), and execute REXX routines directly from memory (the
Macrospace Interface).


ΓòÉΓòÉΓòÉ 3.1. General Characteristics ΓòÉΓòÉΓòÉ

The basic requirements for subcommand, function and system exit handlers are:

o REXX handlers must use the system linkage convention. Handler functions must
  be declared with the appropriate type definition from the REXXSAA.H include
  file:

   - RexxSubcomHandler
   - RexxFunctionHandler
   - RexxExitHandler

o A REXX handler must be packaged as either:

   - An exported routine within a Dynamic Link Library (a dynalink or DLL)
   - An entry point within an executable (EXE) module.

o A handler must be registered with REXX before it can be used. REXX uses the
  registration information to locate and call the handler. For example,
  external function registration of a dynamic link library external function
  identifies both the dynamic link library and routine that contains the
  external function. Also note:

   - Dynamic link library handlers are global to the OS/2* operating system;
     they can be used by any REXX program.

   - EXE file handlers are local to the registering process; handlers packaged
     within an EXE module can only be used by a REXX program running in the
     same process as the EXE module.


ΓòÉΓòÉΓòÉ 4. RXSTRINGs ΓòÉΓòÉΓòÉ

Many of the REXX interfaces pass REXX character strings to and from a REXX
procedure. The RXSTRING data structure is used to describe REXX character
strings. An RXSTRING is a content-insensitive, flat model character string with
a theoretical maximum length of 4 gigabytes. The following structure defines an
RXSTRING:


RXSTRING Data Structure

typedef struct {
   ULONG           strlength;          /*   length of string          */
   PCH             strptr;             /*   pointer to string         */
} RXSTRING;

typedef RXSTRING *PRXSTRING;           /* pointer to an RXSTRING       */

 1. The REXXSAA.H include file contains a number of convenient macros for
    setting and testing RXSTRING values.

 2. An RXSTRING can have a value (including the null string, "") or it can be
    empty.

   o If an RXSTRING has a value, the strptr field will be non-NULL. The
     RXSTRING macro RXVALIDSTRING(string) will return TRUE.

   o If an RXSTRING is the REXX null string (""), the strptr field will be
     non-NULL and the strlength field will be 0. The RXSTRING macro
     RXZEROLENSTRING(string) will return TRUE.

   o If an RXSTRING is empty, the field strptr will be NULL. The RXSTRING macro
     RXNULLSTRING(string) will return TRUE.

 3. When the REXX interpreter passes an RXSTRING to a subcommand handler,
    external function, or exit handler, the interpreter adds a null character
    (hexadecimal zero) at the end of the RXSTRING data. The C string library
    functions can be used on these strings. However, the RXSTRING data can also
    contain null characters. There is no guarantee that the first null
    character encountered in an RXSTRING marks the end of the string. The C
    string functions should only be used when null characters are not expected
    in the RXSTRINGs (such a file names passed to external functions). The
    strlength field in the RXSTRING does not include the terminating null
    character.

 4. When the REXX interpreter calls subcommand handlers, external functions,
    and some exit handlers, the interpreter expects an RXSTRING value returned.
    The interpreter provides a default RXSTRING with a strlength of 256 for the
    returned information. If the returned data is shorter than 256 characters,
    the handler can copy the data into the default RXSTRING and set the
    strlength field to the length returned.

    If the returned data is longer than 256 characters, a new RXSTRING can be
    allocated using "DosAllocMem". The strptr field must point to the new
    storage and the strlength must be set to the string length. The REXX
    interpreter will return the newly allocated storage to the system for the
    handler routine.


ΓòÉΓòÉΓòÉ 5. Invoking the REXX Interpreter ΓòÉΓòÉΓòÉ

A REXX program can be executed directly by the operating system or from within
an application program.


ΓòÉΓòÉΓòÉ 5.1. From the Operating System ΓòÉΓòÉΓòÉ

The CMD.EXE command shell calls the REXX interpreter for the user:

o at command prompts

o in calls from CMD (batch) files

  Note:  Use the OS/2* operating system CALL command to invoke a REXX program
         in a batch file if you want control to return to the caller.

o from the object that represents the program on the OS/2 operating system
  Desktop.


ΓòÉΓòÉΓòÉ 5.2. From Within an Application ΓòÉΓòÉΓòÉ

The REXX interpreter is a dynamic link library (DLL) routine. Any application
can call the REXX interpreter to execute a REXX program. The interpreter is
fully re-entrant and supports REXX procedures running on multiple threads
within the same process.

A C-language prototype for the RexxStart function in the Developer's Toolkit
REXXSAA.H include file.


ΓòÉΓòÉΓòÉ 5.3. RexxStart ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Data Structures
Return Values
Notes
Related Functions
Examples


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxStart ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxStart invokes the REXX interpreter */
/*  to execute a REXX procedure.           */
/*******************************************/

LONG      return_code;  /* interpreter return code    */
RXSTRING  argv[1];      /* program argument string    */
RXSTRING  retstr;       /* program return value       */
LONG      rc;           /* converted return code      */

return_code = RexxStart(1,
                       argv,
                       "CHANGE.ED",
                       NULL,
                       "Editor",
                       RXCOMMAND,
                       NULL,
                       &rc,
                       &retstr);


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxStart ΓòÉΓòÉΓòÉ

RexxStart invokes the REXX interpreter to execute a REXX procedure.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxStart ΓòÉΓòÉΓòÉ

RexxStart  (ArgCount, ArgList, ProgramName, Instore, EnvName, CallType, Exits,
ReturnCode, Result)

Parameters:

ArgCount (LONG) - input
   The number of elements in the ArgList array. This is the value that will be
   returned by the ARG() built-in function in the REXX program. ArgCount
   includes RXSTRINGs which represent omitted arguments. Omitted arguments will
   be empty RXSTRINGs (strptr will be NULL).

ArgList (PRXSTRING) - input
   An array of RXSTRING structures that are the REXX program arguments.

ProgramName (PSZ) - input
   Address of the ASCIIZ name of the REXX procedure. If Instore is NULL, string
   must contain at least the file name of the REXX procedure. An extension,
   drive, and path specification can also be provided. If a file extension is
   not specified, a default of ".CMD" is supplied. A REXX program can use any
   extension. If the path and drive are not provided, the REXX interpreter uses
   the normal OS/2* operating system file search (current directory, then
   environment path).

   If Instore is not NULL, ProgramName is the name used in the PARSE SOURCE
   instruction. If Instore requests a REXX procedure from the macrospace,
   ProgramName is the macrospace function name. (see Macrospace Interface).

Instore (PRXSTRING) - input
   An array of two RXSTRING descriptors for in-storage REXX procedures. If the
   strptr fields of both RXSTRINGs are NULL, the interpreter searches for REXX
   procedure ProgramName in the REXX macrospace (see Macrospace Interface). If
   the procedure is not in the macrospace, the RexxStart function terminates
   with an error return code.

   If either Instore strptr field is not NULL, Instore is used to execute a
   REXX procedure directly from storage.

   Instore[0]
      An RXSTRING describing a memory buffer containing the REXX procedure
      source. The source must be an exact image of a REXX procedure disk file
      (complete with carriage returns, line feeds, and end-of-file characters).

   Instore[1]
      An RXSTRING containing the tokenized image of the REXX procedure. If
      Instore[1] is empty, the REXX interpreter will return the tokenized image
      in Instore[1] when the REXX procedure finishes executing. The tokenized
      image can be used in Instore[1] on subsequent RexxStart function calls.

      If Instore[1] is not empty, interpreter will execute the tokenized image
      directly. The program source provided in Instore[0] is only used if the
      REXX procedure uses the SOURCELINE built-in function. Instore[0] can be
      empty if SOURCELINE is not used. If Instore[0] is empty and the
      SOURCELINE built-in function is used, SOURCELINE will return null strings
      for the REXX procedure source lines.

      If Instore[1] is not empty, but does not contain a valid REXX tokenized
      image, unpredictable results can occur. The REXX interpreter might be
      able to determine that the tokenized image is incorrect and retokenize
      the source.

      Instore[1] is both an input and an output parameter.

   If the procedure is executed from disk, the Instore pointer must be NULL. If
   the first argument string in Arglist contains the string "//T" and the
   CallType is RXCOMMAND, the interpreter will tokenize the procedure source
   and return the tokenized image without running the program.

   The program using the RexxStart function must release Instore[1] using
   "DosFreeMem" when the tokenized image is no longer needed.

   The format of the tokenized image of a REXX program is not a programming
   interface. The tokenized image can only be executed by the same interpreter
   version used to create the image. Therefore, a tokenized image must not be
   moved to other systems or saved for later use. The tokenized image can,
   however, be used multiple times during a single application instance.

EnvName (PSZ) - input
   Address of the ASCIIZ initial ADDRESS environment name. The ADDRESS
   environment is a subcommand handler registered using RexxRegisterSubcomExe
   or RexxRegisterSubcomDll, EnvName is used as the initial setting for the
   REXX ADDRESS instruction.

   If EnvName is NULL, the file extension is used as the initial ADDRESS
   environment. The environment name cannot be longer than 250 characters.

CallType (LONG) - input
   The type of REXX procedure execution. Allowed execution types are:

   RXCOMMAND
      The REXX procedure is an OS/2 operating system command or application
      command. REXX commands normally have a single argument string. The REXX
      PARSE SOURCE instruction will return COMMAND as the second token.

   RXSUBROUTINE
      The REXX procedure is a subroutine of another program. The subroutine can
      have multiple arguments and does not need to return a result. The REXX
      PARSE SOURCE instruction will return SUBROUTINE as the second token.

   RXFUNCTION
      The REXX procedure is a function called from another program. The
      subroutine can have multiple arguments and must return a result. The REXX
      PARSE SOURCE instruction will return FUNCTION as the second token.

Exits (PRXSYSEXIT) - input
   An array of RXSYSEXIT structures defining exits the REXX interpreter will
   use. The RXSYSEXIT structures have the following form:


      RXSYSEXIT Data Structure

      typedef struct {
         PSZ             sysexit_name;       /* name of exit handler        */
         LONG            sysexit_code;       /* system exit function code   */
      } RXSYSEXIT;

   The sysexit_name is the address of an ASCIIZ exit handler name registered
   with RexxRegisterExitExe or RexxRegisterExitDll. sysexit_code is a code
   identifying the handler exit type. See System Exits for exit code
   definitions. The system exit list end is identified by an RXENDLST entry.
   Exits must be NULL if exits are not used.

ReturnCode (PLONG) - output
   The integer form of the Result string. If the Result string is a whole
   number in the range -(2**15) to 2**15-1, it will be converted to an integer
   and and also returned in ReturnCode.

Result (PRXSTRING) - output
   The string returned from the REXX procedure with the REXX RETURN or EXIT
   instruction. A default RXSTRING can be provided for the returned result. If
   a default RXSTRING is not provided or the default is too small for the
   returned result, the REXX interpreter will allocate an RXSTRING using
   "DosAllocMem". The caller of the RexxStart function must release the
   RXSTRING storage with "DosFreeMem".

   The REXX interpreter does not add a terminating null to Result.


ΓòÉΓòÉΓòÉ <hidden> Data Structures - RexxStart ΓòÉΓòÉΓòÉ

RexxStart uses the following data structures:

typedef struct {
   ULONG           strlength;          /*   length of string         */
   PCH             strptr;             /*   pointer to string        */
} RXSTRING;

typedef RXSTRING *PRXSTRING;           /* pointer to an RXSTRING     */

typedef struct {
   PSZ             sysexit_name;       /* name of exit handler        */
   LONG            sysexit_code;       /* system exit function code   */
} RXSYSEXIT;


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxStart ΓòÉΓòÉΓòÉ

RexxStart returns the following values:

negative
   Interpreter errors.

0
   No errors occurred.  The REXX procedure executed normally.

When a macrospace REXX procedure is not loaded in the macrospace, the return
code is -3 ("Program is unreadable").


ΓòÉΓòÉΓòÉ <hidden> Notes - RexxStart ΓòÉΓòÉΓòÉ

The REXX interpreter is a dynamic link library (DLL) routine. Any application
can use the REXX interpreter to execute a REXX program. The interpreter is
fully re-entrant and supports REXX procedures running on multiple threads
within the same process.


ΓòÉΓòÉΓòÉ <hidden> Related Functions - RexxStart ΓòÉΓòÉΓòÉ

The following functions are related to RexxStart:

RexxAddMacro
RexxRegisterSubcomExe
RexxRegisterFunctionExe


ΓòÉΓòÉΓòÉ <hidden> Examples - RexxStart ΓòÉΓòÉΓòÉ

The following example shows the use of RexxStart:

LONG      return_code;                 /* interpreter return code    */
RXSTRING  argv[1];                     /* program argument string    */
RXSTRING  retstr;                      /* program return value       */
LONG      rc;                          /* converted return code      */
CHAR      return_buffer[250];          /* returned buffer            */

                                       /* build the argument string  */
  MAKERXSTRING(argv[0], macro_argument,
      strlen(macro_argument));
                                       /* set up default return      */
  MAKERXSTRING(retstr, return_buffer, sizeof(return_buffer));

  return_code = RexxStart(1,           /* one argument               */
                          argv,        /* argument array             */
                          "CHANGE.ED", /* REXX procedure name        */
                          NULL,        /* use disk version           */
                          "Editor",    /* default address name       */
                          RXCOMMAND,   /* calling as a subcommand    */
                          NULL,        /* no exits used              */
                          &rc,         /* converted return code      */
                          &retstr);    /* returned result            */

                                       /* process return value       */
           .
           .
           .
                                       /* need to return storage?    */
  if (RXSTRPTR(retval) != return_buffer)
    DosFreeMem(RXSTRPTR(retval));      /* release the RXSTRING       */


ΓòÉΓòÉΓòÉ 6. Subcommand Interfaces ΓòÉΓòÉΓòÉ

An application can create named handlers to process commands from a REXX
programs. Once created, the subcommand handler name can be used with the
RexxStart function or the REXX ADDRESS instruction. Subcommand handlers must be
registered with the RexxRegisterSubcomExe or RexxRegisterSubcomDll function
before use.


ΓòÉΓòÉΓòÉ 6.1. Registering Subcommand Handlers ΓòÉΓòÉΓòÉ

A subcommand handler can reside in the same module (EXE or DLL) as an
application, or it can reside in a separate dynamic link library. An
application that executes REXX procedures with RexxStart should use
RexxRegisterSubcomExe to register subcommand handlers. The REXX interpreter
passes commands to the application subcommand handler entry point. Subcommand
handlers created using RexxRegisterSubcomExe are available only to REXX
programs invoked from the registering application.

The RexxRegisterSubcomDll function creates subcommand handlers which reside in
a dynamic link library. A dynamic link library subcommand handler can be
accessed by any REXX program using the REXX ADDRESS instruction. A dynamic link
library subcommand handler can also be registered directly from a REXX program
using the RXSUBCOM command.


ΓòÉΓòÉΓòÉ 6.2. Creating Subcommand Handlers ΓòÉΓòÉΓòÉ

The following example is a sample subcommand handler definition.


Sample Definition of a Subcommand Handler

ULONG command_handler(
  PRXSTRING Command,    /* Command string from REXX                 */
  PUSHORT   Flags,      /* Returned Error/Failure flags             */
  PRXSTRING Retstr)     /* Returned RC string                       */

Where:

Command   The command string created by REXX.

          Command is a null-terminated RXSTRING containing the issued command.

Flags     Subcommand completion status. The subcommand handler can indicate
          success, error, or failure status. The subcommand handler can set
          Flags to one of the following value:

   RXSUBCOM_OK
      The subcommand completed normally. No errors occurred during subcommand
      processing and the REXX procedure will continue when the subcommand
      handler returns.

   RXSUBCOM_ERROR
      A subcommand error occurred. RXSUBCOM_ERROR indicates a subcommand error
      occurred, for example, incorrect command options or syntax.

      If the subcommand handler sets Flags to RXSUBCOM_ERROR, the REXX
      interpreter will raise an ERROR condition if SIGNAL ON ERROR or CALL ON
      ERROR traps have been created. If TRACE ERRORS has been issued, REXX will
      trace the command when the subcommand handler returns.

   RXSUBCOM_FAILURE
      A subcommand failure occurred. RXSUBCOM_FAILURE indicates that general
      subcommand processing errors have occurred. For example, unknown commands
      normally return RXSUBCOM_FAILURE.

      If the subcommand handler sets Flags to RXSUBCOM_FAILURE, the REXX
      interpreter will raise a FAILUREcondition if SIGNAL ON FAILURE or CALL ON
      FAILURE traps have been created. If TRACE FAILURES has been issued, REXX
      will trace the command when the subcommand handler returns.

Retstr    Address of an RXSTRING for the return code. Retstr is a character
          string return code that will be assigned to the REXX special variable
          RC when the subcommand handler returns to REXX. The REXX interpreter
          provides a default 256-byte RXSTRING in Retstr. A longer RXSTRING can
          allocated with "DosAllocMem" if the return string is longer than the
          default RXSTRING. If the subcommand handler sets Retval to an empty
          RXSTRING (a NULL strptr), REXX will assign the string "0" to RC.


ΓòÉΓòÉΓòÉ <hidden> Sample Sucommand Handler ΓòÉΓòÉΓòÉ

ULONG Edit_Commands(
  PRXSTRING Command,    /* Command string passed from the caller    */
  PUSHORT   Flags,      /* pointer to short for return of flags     */
  PRXSTRING Retstr)     /* pointer to RXSTRING for RC return        */
{
  LONG      command_id;                /* command to process         */
  LONG      rc;                        /* return code                */
  PSZ       scan_pointer;              /* current command scan       */
  PSZ       target;                    /* general editor target      */

  scan_pointer = command->strptr;      /* point to the command       */
                                       /* resolve command            */
  command_id = resolve_command(&scan_pointer);

  switch (command_id) {                /* process based on command   */

    case   LOCATE:                     /* locate command             */

                                       /* validate rest of command   */
      if (rc = get_target(&scan_pointer, &target)) {
        *Flags = RXSUBCOM_ERROR;       /* raise an error condition   */
        break;                         /* return to REXX             */
      }
      rc = locate(target);             /* look target in the file    */
      *Flags = RXSUBCOM_OK;            /* not found is not an error  */
      break;                           /* go finish up               */

       .
       .
       .

    default:                           /* unknown command            */
      rc = 1;                          /* return code for unknown    */
      *Flags = RXSUBCOM_FAILURE;       /* this is a command failure  */
      break;
  }

  sprintf(Retstr->strptr, "%d", rc);   /* format return code string  */
                                       /* and set the correct length */
  Retstr->strlength = strlen(Retstr->strptr);
  return 0;                            /* processing completed       */
}


ΓòÉΓòÉΓòÉ 7. Subcommand Interface Functions ΓòÉΓòÉΓòÉ

o RexxRegisterSubcomDll registers a subcommand handler that resides in a
  dynamic link library routine.

o RexxRegisterSubcomExe registers a subcommand handler that resides within
  application code.

o RexxDeregisterSubcom deregisters a subcommand handler.

o RexxQuerySubcom queries a subcommand handler and retrieves saved user
  information.


ΓòÉΓòÉΓòÉ 7.1. RexxRegisterSubcomDll ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Return Values
Errors
Notes
Related Functions
Sample Programs


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxRegisterSubcomDll ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxRegisterSubcomDll registers a      */
/*  subcommand handler that resides in a   */
/*  dynamic link library routine.          */
/*******************************************/

#define INCL_RXSUBCOM       /* Subcommand handler values */

PSZ     name;         /* handler name */
PSZ     library;      /* DLL name     */
PSZ     routine;      /* routine name */
ULONG   rc;           /* Return code  */
ULONG   userdata[2];  /* save userdata*/

rc = RexxRegisterSubcomDll(name, library, routine,
     userdata, RXSUBCOM_DROPPABLE);


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxRegisterSubcomDll ΓòÉΓòÉΓòÉ

RexxRegisterSubcomDll registers a subcommand handler that resides in a dynamic
link library routine.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxRegisterSubcomDll ΓòÉΓòÉΓòÉ

RexxRegisterSubcomDll (EnvName, ModuleName, EntryPoint, UserArea, DropAuth)

Parameters:

EnvName (PSZ) - input
   Address of an ASCIIZ subcommand handler name.

ModuleName (PSZ) - input
   Address of an ASCIIZ dynamic link library name. ModuleName is the DLL file
   containing the subcommand handler routine.

EntryPoint (PSZ) - input
   Address of an ASCIIZ dynamic link library procedure name. EntryPoint is the
   name of the exported routine within ModuleName that is the REXX subcommand
   handler.

UserArea (PUCHAR) - input
   Address of an 8-byte area of user defined information. The 8 bytes addressed
   by UserArea will be saved with the subcommand handler registration. UserArea
   can be NULL if there is no user information to save. The saved user
   information can be retrieved with the RexxQuerySubcom function.

DropAuth (ULONG) - input
   The drop authority. DropAuth identifies the processes that can deregister
   the subcommand handler. The possible DropAuth values are:

   RXSUBCOM_DROPPABLE
      Any process can deregister the subcommand handler with
      RexxDeregisterSubcom.

   RXSUBCOM_NONDROP
      Only a thread within the same process as the thread that registered the
      handler can deregister the handler with RexxDeregisterSubcom.


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxRegisterSubcomDll ΓòÉΓòÉΓòÉ

RexxRegisterSubcomDll returns the following values:

0         RXSUBCOM_OK
10        RXSUBCOM_DUP
1002      RXSUBCOM_NOEMEM
1003      RXSUBCOM_BADTYPE


ΓòÉΓòÉΓòÉ <hidden> Notes - RexxRegisterSubcomDll ΓòÉΓòÉΓòÉ

EntryPoint can be either a 16-bit or a 32-bit routine. REXX will invoke the
handler in the correct addressing mode.

A REXX procedure can register dynamic link library subcommand handlers with the
RXSUBCOM command. For example:

                                 /* register Dialog Manager       */
                                 /* subcommand handler            */
  'RXSUBCOM REGISTER ISPCIR ISPCIR ISPCIR'
  Address ispcir                 /* send commands to dialog mgr   */

The RXSUBCOM command registers the Dialog Manager subcommand handler ISPCIR as
routine ISPCIR in the ISPCIR dynamic link library.


ΓòÉΓòÉΓòÉ <hidden> Related Functions - RexxRegisterSubcomDll ΓòÉΓòÉΓòÉ

The following functions are related to RexxRegisterSubcomDll:

RexxRegisterSubcomExe
RexxDeregisterSubcom
RexxQuerySubcom
RexxStart


ΓòÉΓòÉΓòÉ 7.2. RexxRegisterSubcomExe ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Return Values
Errors
Notes
Related Functions
Examples
Sample Programs


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxRegisterSubcomExe ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxRegisterSubcomExe registers a      */
/*  subcommand handler that resides within */
/*  application code .                     */
/*******************************************/

#define INCL_RXSUBCOM       /* Subcommand handler values */

PSZ     name;         /* handler name */
ULONG   rc;           /* Return code  */
ULONG   userdata[2];  /* save userdata*/

rc = RexxRegisterSubcomExe(name, &handler_routine,
     userdata);


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxRegisterSubcomExe ΓòÉΓòÉΓòÉ

RexxRegisterSubcomExe registers a subcommand handler that resides within
application code.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxRegisterSubcomExe ΓòÉΓòÉΓòÉ

RexxRegisterSubcomExe (EnvName, EntryPoint, UserArea)

Parameters:

EnvName (PSZ) - input
   Address of an ASCIIZ subcommand handler name.

EntryPoint (PFN) - input
   Address of the subcommand handler entry point within the application EXE
   code. pt.UserArea (PUCHAR) - input pd. Address of an 8-byte area of user
   defined information. The 8 bytes addressed by UserArea will be saved with
   the subcommand handler registration. UserArea can be NULL if there is no
   user information to save. The user information can be retrieved with the
   RexxQuerySubcom function.


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxRegisterSubcomExe ΓòÉΓòÉΓòÉ

RexxRegisterSubcomExe returns the following values:

0         RXSUBCOM_OK
10        RXSUBCOM_DUP
30        RXSUBCOM_NOTREG
1002      RXSUBCOM_NOEMEM
1003      RXSUBCOM_BADTYPE


ΓòÉΓòÉΓòÉ <hidden> Notes - RexxRegisterSubcomExe ΓòÉΓòÉΓòÉ

If EnvName is same as a subcommand handler already registered with
RexxRegisterSubcomDll, RexxRegisterSubcomExe will return RXSUBCOM_DUP. This is
not an error condition. RexxRegisterSubcomExe has successfully registered the
new subcommand handler.


ΓòÉΓòÉΓòÉ <hidden> Related Functions - RexxRegisterSubcomExe ΓòÉΓòÉΓòÉ

The following functions are related to RexxRegisterSubcomExe:

RexxRegisterSubcomDll
RexxDeregisterSubcom
RexxQuerySubcom
RexxStart


ΓòÉΓòÉΓòÉ <hidden> Examples - RexxRegisterSubcomExe ΓòÉΓòÉΓòÉ

The following example shows the use of RexxRegisterSubcomExe:

  WORKAREARECORD  *user_info[2];       /* saved user information     */

  user_info[0] = global_workarea;      /* save global work area for  */
  user_info[1] = NULL;                 /* re-entrancy                */

  rc = RexxRegisterSubcomExe("Editor", /* register editor handler    */
      &Edit_Commands,                  /* located at this address    */
      user_info);                      /* save global pointer        */


ΓòÉΓòÉΓòÉ 7.3. RexxDeregisterSubcom ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Return Values
Errors
Notes
Related Functions


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxDeregisterSubcom ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxDeregisterSubcom deregisters a      */
/*  subcommand handler.                    */
/*******************************************/

#define INCL_RXSUBCOM       /* Subcommand handler values */

PSZ     name;       /* handler name       */
PSZ     library     /* handler dll        */
ULONG   rc;         /* Return code */

rc = RexxDeregisterSubcom(name, library);


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxDeregisterSubcom ΓòÉΓòÉΓòÉ

RexxDeregisterSubcom deregisters a subcommand handler.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxDeregisterSubcom ΓòÉΓòÉΓòÉ

RexxDeregisterSubcom (EnvName, ModuleName)

Parameters:

EnvName (PSZ) - input
   Address of an ASCIIZ subcommand handler name.

ModuleName (PSZ) - input
   Address of an ASCIIZ dynalink library name. ModuleName is the name of the
   dynalink library containing the registered subcommand handler. When
   ModuleName is NULL, RexxDeregisterSubcom searches the RexxRegisterSubcomExe
   subcommand handler list for a handler within the current process. If
   RexxDeregisterSubcom does not find a RexxRegisterSubcomExe handler, it will
   search the RexxRegisterSubcomDll subcommand handler list.


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxDeregisterSubcom ΓòÉΓòÉΓòÉ

RexxDeregisterSubcom returns the following values:

0         RXSUBCOM_OK
30        RXSUBCOM_NOTREG
40        RXSUBCOM_NOCANDROP
1003      RXSUBCOM_BADTYPE


ΓòÉΓòÉΓòÉ <hidden> Notes - RexxDeregisterSubcom ΓòÉΓòÉΓòÉ

The handler is removed from the active subcommand handler list.


ΓòÉΓòÉΓòÉ <hidden> Related Functions - RexxDeregisterSubcom ΓòÉΓòÉΓòÉ

The following functions are related to RexxDeregisterSubcom:

RexxRegisterSubcomDll
RexxRegisterSubcomExe
RexxQuerySubcom


ΓòÉΓòÉΓòÉ 7.4. RexxQuerySubcom ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Return Values
Errors
Related Functions
Examples


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxQuerySubcom ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxQuerySubcom queries a subcommand   */
/*  handler and retrieves saved user       */
/*  information.                           */
/*******************************************/

#define INCL_RXSUBCOM       /* subcommand handler values */

PSZ     name;         /* handler name */
PSZ     library;      /* DLL name     */
ULONG   userdata[2];  /* saved information */
ULONG   rc;         /* Return code */

rc = RexxQuerySubcom(name, library, userdata);


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxQuerySubcom ΓòÉΓòÉΓòÉ

RexxQuerySubcom queries a subcommand handler and retrieves saved user
information.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxQuerySubcom ΓòÉΓòÉΓòÉ

RexxQuerySubcom (EnvName, ModuleName, Flag, UserWord)

Parameters:

EnvName (PSZ) - input
   Address of an ASCIIZ subcommand handler name.

ModuleName (PSZ) - input
   Address of an ASCIIZ dynamic link library name. ModuleName restricts the
   query to a subcommand handler within the ModuleName dynamic link library.
   When ModuleName is NULL, RexxQuerySubcom searches the RexxRegisterSubcomExe
   subcommand handler list for a handler within the current process. If
   RexxQuerySubcom does not find a RexxRegisterSubcomExe handler, it will
   search the RexxRegisterSubcomDll subcommand handler list.

Flag (PUSHORT) - output
   Subcommand handler registration flag. Flag is the EnvName subcommand handler
   registration status. When RexxQuerySubcom returns RXSUBCOM_OK, the EnvName
   subcommand handler is currently registered. When RexxQuerySubcom returns
   RXSUBCOM_NOTREG, the EnvName subcommand handler is not registered.

UserWord (PUCHAR) - output
   Address of an 8-byte area to receive the user information saved with
   RexxRegisterSubcomExe or RexxRegisterSubcomDll. UserWord can be NULL if the
   saved user information is not required.


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxQuerySubcom ΓòÉΓòÉΓòÉ

RexxQuerySubcom returns the following values:

0         RXSUBCOM_OK
30        RXSUBCOM_NOTREG
1003      RXSUBCOM_BADTYPE


ΓòÉΓòÉΓòÉ <hidden> Related Functions - RexxQuerySubcom ΓòÉΓòÉΓòÉ

The following functions are related to RexxQuerySubcom:

RexxRegisterSubcomDll
RexxRegisterSubcomExe
RexxDeregisterSubcom


ΓòÉΓòÉΓòÉ <hidden> Examples - RexxQuerySubcom ΓòÉΓòÉΓòÉ

The following examples show the use of RexxQuerySubcom:

ULONG Edit_Commands(
  PRXSTRING Command,    /* Command string passed from the caller    */
  PUSHORT   Flags,      /* pointer to short for return of flags     */
  PRXSTRING Retstr)     /* pointer to RXSTRING for RC return        */
{
  WORKAREARECORD  *user_info[2];       /* saved user information     */
  WORKAREARECORD   global_workarea;    /* application data anchor    */
  USHORT           query_flag;         /* flag for handler query     */


  rc = RexxQuerySubcom("Editor",       /* retrieve application work  */
      NULL,                            /* area anchor from REXX.     */
      &query_flag,
      user_info);

  global_workarea = user_info[0];      /* set the global anchor      */


ΓòÉΓòÉΓòÉ <hidden> Subcommand Interface Errors ΓòÉΓòÉΓòÉ

The following are the subcommand handler function errors.:

RXSUBCOM_NOEMEM
   There is insufficient memory available to complete this request.

RXSUBCOM_OK
   A subcommand function has executed successfully.

RXSUBCOM_DUP
   A duplicate handler name has been successfully registered; there is either:

   o an EXE handler with the same name registered in another process, or

   o a DLL handler with the same name registered in another DLL; to address
     this subcommand, its library name must be specified.

RXSUBCOM_NOTREG
   This indicates:

   o registration was unsuccessful due to duplicate handler and dynalink names
     (RexxRegisterSubcomExe or RexxRegisterSubcomDll)

   o the subcommand handler is not registered (other REXX subcommand
     functions).

RXSUBCOM_NOCANDROP
   The subcommand handler has been registered as "not droppable".


ΓòÉΓòÉΓòÉ 8. External Functions ΓòÉΓòÉΓòÉ

There are two types of REXX external functions:

 1. Routines written in REXX

 2. Routines written in other OS/2* operating system supported languages.
External functions written in the REXX language are not registered with REXX.
the REXX functions are found by a disk search for a REXX procedure file that
matches the function name. Functions written in other languages, however, must
be registered with the REXX interpeter.


ΓòÉΓòÉΓòÉ 8.1. Registering External Functions ΓòÉΓòÉΓòÉ

An external function can reside in the same module (EXE or DLL) as an
application, or it can reside in a separate dynamic link library.
RexxRegisterFunctionExe registers external functions within an application
module. External functions registered with RexxRegisterFunctionExe

The RexxRegisterFunctionDll function registers external functions that reside
in a dynamic link library. Once registered, a dynamic link library external
function can be accessed by any REXX program. A dynamic link library external
function can also be registered directly from a REXX program using the REXX
RxFuncAdd built-in function.


ΓòÉΓòÉΓòÉ 8.2. Creating External Functions ΓòÉΓòÉΓòÉ

The following is a sample external function definition:


Sample External Function Definition

ULONG SysLoadFuncs(
     PSZ       Name,                   /* name of the function       */
     LONG      Argc,                   /* number of arguments        */
     RXSTRING  Argv[],                 /* list of argument strings   */
     PSZ       Queuename,              /* current queue name         */
     PRXSTRING Retstr)                 /* returned result string     */

Where

Name        Address of ASCIIZ external function name.

Argc        The size of the argument list. Argv will contain Argc RXSTRINGs.

Argv        An array of null-terminated RXSTRINGs for the function arguments.

Queue       The name of the currently defined REXX external data queue.

Retstr      Address of an RXSTRING for the returned value. Retstr is a
            character string function or subroutine return value. When a REXX
            program calls an external function with the REXX CALL instruction,
            Retstr is assigned to the REXX special variable RESULT. When the
            REXX program calls an external function as a function, Retstr is
            used directly within the REXX expression.

            The REXX interpreter provides a default 256-byte RXSTRING in
            Retstr. A longer RXSTRING can allocated with "DosAllocMem" if the
            returned string is longer name 256 bytes. The REXX interpreter
            releases Retstr with "DosFreeMem" when the external function
            completes.

Returns     An integer return code from the function. When the external
            function returns 0, the function completed successfully. Retstr
            contains the function return value. When external function return
            code is not 0, the REXX interpreter raises REXX error 40 ("Invalid
            call to routine").  The Retstr value is ignored.

            If the external function does not have a return value, the function
            must set Retstr to an an empty RXSTRING (NULL strptr). When a
            function does not return a value, the interpreter raises error 44,
            "Function did not return data". When an external function invoked
            with the REXX CALL instruction does not return a value, the REXX
            interpreter drops (unassigns) the special variable RESULT.


ΓòÉΓòÉΓòÉ 8.3. Calling External Functions ΓòÉΓòÉΓòÉ

RexxRegisterFunctionExe Only REXX procedures running in the same process can
use the registered external function. It is possible to register functions with
the same external function name if they are registered from different
processes. However, RexxRegisterFunctionDll functions are available from all
processes. The function names cannot be duplicated.


ΓòÉΓòÉΓòÉ 8.4. Sample External Function ΓòÉΓòÉΓòÉ

ULONG SysMkDir(
     PSZ       Name,                   /* name of the function       */
     LONG      Argc,                   /* number of arguments        */
     RXSTRING  Argv[],                 /* list of argument strings   */
     PSZ       Queuename,              /* current queue name         */
     PRXSTRING Retstr)                 /* returned result string     */
{
  ULONG  rc;                           /* Return code of function    */

  if (Argc != 1)                       /* must be 1 argument         */
    return 40;                         /* incorrect call if not      */

                                       /* make the directory using   */
                                       /* the null-terminated        */
  rc = DosMkDir(Argv[0].strptr, 0L);   /* directly                   */

  sprintf(Retstr->strptr, "%d", rc);   /* result is return code      */
                                       /* set proper string length   */
  Retstr->strlength = strlen(Retstr->strptr);
  return 0;                            /* successful completion      */
}


ΓòÉΓòÉΓòÉ 9. External Function Interface Functions ΓòÉΓòÉΓòÉ

o RexxRegisterFunctionDll registers an external function that resides in a
  dynamic link library routine.

o RexxRegisterFunctionExe registers an external function that resides within
  application code.

o RexxDeregisterFunction deregisters an external function.

o RexxQueryFunction queries the existence of a registered external function.


ΓòÉΓòÉΓòÉ 9.1. RexxRegisterFunctionDll ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Return Values
Errors
Notes
Related Functions
Examples


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxRegisterFunctionDll ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxRegisterFunctionDll registers an   */
/*  external function that resides in a    */
/*  dynamic link library routine.          */
/*******************************************/

#define INCL_RXFUNC       /* External function values */

PSZ     name;         /* function name */
PSZ     library;      /* DLL name      */
PSZ     routine;      /* routine name  */
ULONG   rc;           /* Return code   */

rc = RexxRegisterFunctionDll(name, library, routine);


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxRegisterFunctionDll ΓòÉΓòÉΓòÉ

RexxRegisterFunctionDll registers an external function that resides in a
dynamic link library routine.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxRegisterFunctionDll ΓòÉΓòÉΓòÉ

RexxRegisterFunctionDll (FuncName, ModuleName, EntryPoint)

Parameters:

FuncName (PSZ) - input
   Address of an ASCIIZ external function name.

ModuleName (PSZ) - input
   Address of an ASCIIZ dynamic link library name. ModuleName is the DLL file
   containing the external function routine.

EntryPoint (PSZ) - input
   Address of an ASCIIZ dynamic link procedure name. EntryPoint is exported
   external function routine within ModuleName.


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxRegisterFunctionDll ΓòÉΓòÉΓòÉ

RexxRegisterFunctionDll returns the following values:

0         RXFUNC_OK
10        RXFUNC_DEFINED
20        RXFUNC_NOMEM


ΓòÉΓòÉΓòÉ <hidden> Notes - RexxRegisterFunctionDll ΓòÉΓòÉΓòÉ

EntryPoint can be either a 16-bit or 32-bit routine. REXX will invoke the
function in the correct addressing mode.

A REXX procedure can register dynamic link library subcommand handlers with the
RxFuncAdd built-in function. For example:

                                 /* register function SysLoadFuncs*/
                                 /* in dynalink library REXXUTIL  */
  Call RxFuncAdd 'SysLoadFuncs', 'REXXUTIL', 'SysLoadFuncs'
  Call SysLoadFuncs              /* call to load other functions  */

The RxFuncAdd registers the external function SysLoadFuncs as routine
SysLoadFuncs in the REXXUTIL dynamic link library. SysLoadFuncs registers
additional functions in REXXUTIL.DLL with RexxRegisterFunctionDll.


ΓòÉΓòÉΓòÉ <hidden> Related Functions - RexxRegisterFunctionDll ΓòÉΓòÉΓòÉ

The following functions are related to RexxRegisterFunctionDll:

RexxRegisterFunctionExe
RexxDeregisterFunction
RexxQueryFunction


ΓòÉΓòÉΓòÉ <hidden> Examples - RexxRegisterFunctionDll ΓòÉΓòÉΓòÉ

The following example shows the use of RexxRegisterFunctionDll:

static PSZ  RxFncTable[] =             /* function package list      */
{
      "SysCls",
      "SysCurpos",
      "SysCurState",
      "SysDriveInfo",
}


ULONG SysLoadFuncs(
     PSZ       Name,                   /* name of the function       */
     LONG      Argc,                   /* number of arguments        */
     RXSTRING  Argv[],                 /* list of argument strings   */
     PSZ       Queuename,              /* current queue name         */
     PRXSTRING Retstr)                 /* returned result string     */
{
  INT    entries;                      /* Num of entries             */
  INT    j;                            /* Counter                    */

  Retstr->strlength = 0;               /* set null string return     */

  if (Argc > 0)                        /* check arguments            */
    return 40;                         /* too many, raise an error   */

                                       /* get count of arguments     */
  entries = sizeof(RxFncTable)/sizeof(PSZ);
                                       /* register each function in  */
  for (j = 0; j < entries; j++) {      /* the table                  */
    RexxRegisterFunctionDll(RxFncTable[j],
          "REXXUTIL", RxFncTable[j]);
  }
  return 0;                            /* successful completion      */
}


ΓòÉΓòÉΓòÉ 9.2. RexxRegisterFunctionExe ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Return Values
Errors
Related Functions


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxRegisterFunctionExe ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxRegisterFunctionExe registers an   */
/*  external function that resides within  */
/*  application code.                      */
/*******************************************/

#define INCL_RXFUNC       /* external function values */

PSZ     name;         /* handler name */
ULONG   rc;           /* Return code  */
ULONG   userdata[2];  /* save userdata*/

rc = RexxRegisterSubcomExe(name, &external_function);


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxRegisterFunctionExe ΓòÉΓòÉΓòÉ

RexxRegisterFunctionExe registers an external function that resides within
application code.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxRegisterFunctionExe ΓòÉΓòÉΓòÉ

RexxRegisterFunctionExe (FuncName, EntryPoint)

Parameters:

FuncName (PSZ) - input
   Address of an ASCIIZ external function name.

EntryPoint (PFN) - input
   Address of the external function entry point within the application EXE
   file. Functions registered with RexxRegisterFunctionExe are local to the
   current process. REXX procedures in the same process as the
   RexxRegisterFunctionExe function caller can use local external functions.


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxRegisterFunctionExe ΓòÉΓòÉΓòÉ

RexxRegisterFunctionExe returns the following values:

0         RXFUNC_OK
10        RXFUNC_DEFINED
20        RXFUNC_NOMEM


ΓòÉΓòÉΓòÉ <hidden> Related Functions - RexxRegisterFunctionExe ΓòÉΓòÉΓòÉ

The following functions are related to RexxRegisterFunctionExe:

RexxRegisterFunctionDll
RexxDeregisterFunction
RexxQueryFunction


ΓòÉΓòÉΓòÉ 9.3. RexxDeregisterFunction ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Return Values
Errors
Related Functions


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxDeregisterFunction ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxDeregisterFunction deregisters an   */
/*  external function.                     */
/*******************************************/

#define INCL_RXFUNC       /* External Function values */

PSZ     name;       /* function name      */
ULONG   rc;         /* Return code        */

rc = RexxDeregisterFunction(name);


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxDeregisterFunction ΓòÉΓòÉΓòÉ

RexxDeregisterFunction deregisters an external function.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxDeregisterFunction ΓòÉΓòÉΓòÉ

RexxDeregisterFunction (FuncName)

Parameters:

FuncName (PSZ) - input
   Address of an ASCIIZ external function name to deregister.


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxDeregisterFunction ΓòÉΓòÉΓòÉ

RexxDeregisterFunction returns the following values:

0         RXFUNC_OK
30        RXFUNC_NOTREG


ΓòÉΓòÉΓòÉ <hidden> Related Functions - RexxDeregisterFunction ΓòÉΓòÉΓòÉ

The following functions are related to RexxDeregisterFunction:

RexxRegisterFunctionDll
RexxRegisterFunctionExe
RexxQueryFunction


ΓòÉΓòÉΓòÉ 9.4. RexxQueryFunction ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Return Values
Errors
Notes
Related Functions


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxQueryFunction ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxQueryFunction queries the          */
/*  existence of a registered external     */
/*  function.                              */
/*******************************************/

#define INCL_RXFUNC      /* External function values */

PSZ     name;       /* function name */
ULONG   rc;         /* Return code */

rc = RexxQueryFunction(name);


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxQueryFunction ΓòÉΓòÉΓòÉ

RexxQueryFunction queries the existence of a registered external function.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxQueryFunction ΓòÉΓòÉΓòÉ

RexxQueryFunction (FuncName)

Parameters:

FuncName (PSZ) - input
   Address of an ASCIIZ external function name to query.


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxQueryFunction ΓòÉΓòÉΓòÉ

RexxQueryFunction returns the following values:

0         RXFUNC_OK
30        RXFUNC_NOTREG


ΓòÉΓòÉΓòÉ <hidden> Notes - RexxQueryFunction ΓòÉΓòÉΓòÉ

RexxQueryFunction will only return RXFUNC_OK if the requested function is
available to the current process. If a function is not available to the current
process, RexxQueryFunction search will search the RexxRegisterFunctionDll
external function list.


ΓòÉΓòÉΓòÉ <hidden> Related Functions - RexxQueryFunction ΓòÉΓòÉΓòÉ

The following functions are related to RexxQueryFunction:

RexxRegisterFunctionDll
RexxRegisterFunctionExe
RexxDeregisterFunction


ΓòÉΓòÉΓòÉ <hidden> External Function Interface Errors ΓòÉΓòÉΓòÉ

The following are the external function interface errors.:

RXFUNC_OK
   The function call completed successfully.

RXFUNC_DEFINED
   The requested function is already registered.

RXFUNC_NOMEM
   There is not enough memory to register a new function.

RXFUNC_NOTREG
   The requested function is not registered.


ΓòÉΓòÉΓòÉ 10. System Exits ΓòÉΓòÉΓòÉ

The REXX System Exits create user-define REXX interpreter operating
environment. Application defined exit handlers process specified REXX
interpreter activities.

Applications can create exits for:

o The administration of resources at the beginning and end of interpretation.

o Linkages to external functions and subcommand handlers.

o Special language features. For example, input and output to standard
  resources.

o Polling for halt and external trace events.

Exit handlers are similar to subcommand handlers and external functions:

o Applications must registers named exit handlers with the REXX interpreter.

o Exit handlers can reside in dynamic link libraries or within an application
  EXE module.


ΓòÉΓòÉΓòÉ 10.1. Writing System Exit Handlers ΓòÉΓòÉΓòÉ

The following is a sample exit handler definition:


Sample System Exit Handler Definition

LONG Rexx_IO_exit(
     LONG  ExitNumber,    /* code defining the exit function    */
     LONG  Subfunction,   /* code defining the exit subfunction */
     PEXIT ParmBlock)     /* function dependent control block   */

Where:

ExitNumber  The major function code defining the type of exit.

Subfunction The subfunction code defining the exit event.

ParmBlock   A pointer to the exit parameter list.

            The exit parameter list contains exit specific information. See the
            exit descriptions below parameter list formats.

            Note:  Some exit subfunctions do not have parameters. ParmBlock for
                   exit subfunctions without parameters.


ΓòÉΓòÉΓòÉ 10.1.1. Exit Return Codes ΓòÉΓòÉΓòÉ

Exit handlers return an integer value that signals one of three actions:

RXEXIT_HANDLED
   The exit handler processed the exit subfunction and updated the subfunction
   parameter list as required. The REXX interpreter continues with normal
   processing.

RXEXIT_NOT_HANDLED
   The exit handler did not process the exit subfunction. The REXX interpreter
   processes the subfunction as if the exit handler was not called.

RXEXIT_RAISE_ERROR
   A fatal error occurred in the exit handler. The REXX interpreter raises REXX
   error 48 ("Failure in system service").

For example, if an application creates an input/output exit handler:

o When the exit handler returns RXEXIT_NOT_HANDLED for an RXSIOSAY subfunction,
  the REXX interpreter writes the output line to STDOUT.

o When the exit handler returns RXEXIT_HANDLED for an RXSIOSAY subfunction, the
  REXX interpreter assumes the exit handler has performed all required output.
  The interpreter will not write the output line to STDOUT.

o When the exit handler returns RXEXIT_RAISE_ERROR for an RXSIOSAY subfunction,
  the interpreter raise REXX error 48, "Failure in system service".


ΓòÉΓòÉΓòÉ 10.1.2. Exit Parameters ΓòÉΓòÉΓòÉ

Each exit subfunction has a different parameter list. All RXSTRING exit
subfunction parameters are passed as null-terminated RXSTRINGs. It is possible
that the RXSTRING value will contain null characters also.

For some exit subfunctions, the exit handler can return an RXSTRING character
result in the parameter list. The interpreter provides a default 256-byte for
RXSTRING result strings. If the result is longer than 256 bytes, a new RXSTRING
can be allocated using "DosAllocMem". The REXX interpreter will return the
RXSTRING storage for the exit handler.


ΓòÉΓòÉΓòÉ 10.1.3. Identifying Exit Handlers to REXX ΓòÉΓòÉΓòÉ

System exit handlers must be registered with RexxRegisterExitDll or
RexxRegisterExitExe The system exit handler registration is similar to
subcommand handler registration.

The REXX system exits are enabled with the RexxStart function parameter Exits.
Exits is a pointer to an array of RXSYSEXIT structures. Each RXSYSEXIT
structure in the array contains a REXX exit code and the address of an ASCIIZ
exit handler name. The RXENDLST exit code marks the exit list end.

The REXX interpreter calls the registered exit handler in sysexit_name for all
sysexit_code subfunctions.
Example


Sample System Exit Usage

WORKAREARECORD  *user_info[2];         /* saved user information     */
RXSYSEXIT exit_list[2];                /* system exit list           */

  user_info[0] = global_workarea;      /* save global work area for  */
  user_info[1] = NULL;                 /* re-entrancy                */

  rc = RexxRegisterExitExe("EditInit", /* register exit handler      */
      &Init_exit,                      /* located at this address    */
      user_info);                      /* save global pointer        */

                                       /* set up for RXINI exit      */
  exit_list[0].sysexit_name = "EditInit";
  exit_list[0].sysexit_code = RXINI;
  exit_list[1].sysexit_code = RXENDLST;

  return_code = RexxStart(1,           /* one argument               */
                          argv,        /* argument array             */
                          "CHANGE.ED", /* REXX procedure name        */
                          NULL,        /* use disk version           */
                          "Editor",    /* default address name       */
                          RXCOMMAND,   /* calling as a subcommand    */
                          exit_list,   /* no exits used              */
                          &rc,         /* converted return code      */
                          &retstr);    /* returned result            */

                                       /* process return value       */
           .
           .
           .
}

LONG Init_exit(
     LONG  ExitNumber,    /* code defining the exit function    */
     LONG  Subfunction,   /* code defining the exit subfunction */
     PEXIT ParmBlock)     /* function dependent control block   */
{
  WORKAREARECORD  *user_info[2];       /* saved user information     */
  WORKAREARECORD   global_workarea;    /* application data anchor    */
  USHORT           query_flag;         /* flag for handler query     */


  rc = RexxQueryExit("EditInit",       /* retrieve application work  */
      NULL,                            /* area anchor from REXX.     */
      &query_flag,
      user_info);

  global_workarea = user_info[0];      /* set the global anchor      */

  if (global_workarea->rexx_trace)     /* trace at start?            */
                                       /* turn on macro tracing      */
    RexxSetTrace(global_workarea->rexx_pid, global_workarea->rexx_tid);
  return RXEXIT_HANDLED;               /* successfully handled       */
}


ΓòÉΓòÉΓòÉ 10.2. System Exit Definitions ΓòÉΓòÉΓòÉ

The REXX interpreter supports the following system exits:

RXFNC     External function call exit

   RXFNCCAL    Call an external function

RXCMD     Subcommand call exit

   RXCMDHST    Call a subcommand handler

RXMSQ     External data queue exit

   RXMSQPLL    Pull a line from the external data queue.
   RXMSQPSH    Place a line on the external data queue.
   RXMSQSIZ    Return number of lines on the external data queue.
   RXMSQNAM    Set active external data queue name.

RXSIO     Standard input and output exit.

   RXSIOSAY    Write a line to the standard output stream for the SAY
               instruction.
   RXSIOTRC    Write a line to the standard error stream for REXX trace or REXX
               error messages.
   RXSIOTRD    Read a line from the standard input stream for PULL or PARSE
               PULL.
   RXSIODTR    Read a line from the standard input stream for interactive
               debug.

RXHLT     Halt processing exit

   RXHLTTST    Test for a HALT condition.
   RXHLTCLR    Clear a HALT condition.

RXTRC     External trace exit

   RXTRCTST    Test for an external trace event.

RXINI     Initialization exit

   RXINIEXT    Allow additional REXX procedure initialization.

RXTER     Termination exit

   RXTEREXT    Process REXX procedure termination.

Each exit subfunction has the following characteristics:

o When REXX calls the exit handler.

o The default action when the exit is not provided or the exit handler does not
  process the subfunction.

o The subfunction parameter list.

o The service the subfunction provides.

o The state of the variable pool interface during the exit handler call. The
  variable pool interface is fully enabled for the RXCMD, RXFNC, RXINT, and
  RXTER exit handler calls. The variable pool interface is enabled for
  RXSHV_EXIT requests for RXHLT, RXCMD, RXFNC, RXSIO, and RXMSQ exit handler
  calls.


ΓòÉΓòÉΓòÉ 10.3. RXFNC ΓòÉΓòÉΓòÉ

Process external function calls.

The RXFNC exit has the following subfunction:

RXFNCCAL    Process external function calls.


ΓòÉΓòÉΓòÉ 10.3.1. RXFNCCAL ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics - RXFNCCAL ΓòÉΓòÉΓòÉ

Process external function calls.

When called: When a REXX program calls an external subroutine or function.

Default action: Call the external routine using the normal external function
search order.

Exit Action: Call the external routine, if possible.

Continuation: If necessary, raise REXX error 40 ("Invalid call to routine"), 43
("Routine not found"), or 44 ("Function did not return data").

Note:  The variable pool interface is fully enabled during RXFNC exit handler
       calls.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RXFNCCAL ΓòÉΓòÉΓòÉ

typedef struct {
   struct {
      unsigned rxfferr  : 1;           /* Invalid call to routine.    */
      unsigned rxffnfnd : 1;           /* Function not found.         */
      unsigned rxffsub  : 1;           /* Called as a subroutine if   */
                                       /* TRUE.  Return values are    */
                                       /* optional for subroutines,   */
                                       /* required for functions.     */
   } rxfnc_flags ;

   PUCHAR            rxfnc_name;       /* Pointer to function name.   */
   USHORT            rxfnc_namel;      /* Length of function name.    */
   PUCHAR            rxfnc_que;        /* Current queue name.         */
   USHORT            rxfnc_quel;       /* Length of queue name.       */
   USHORT            rxfnc_argc;       /* Number of args in list.     */
   PRXSTRING         rxfnc_argv;       /* Pointer to argument list.   */
                                       /* List mimics argv list for   */
                                       /* function calls, an array of */
                                       /* RXSTRINGs.                  */
   RXSTRING          rxfnc_retc;       /* Return value.               */
} RXFNCCAL_PARM;

The name of the external function is defined by rxfnc_name and rxfnc_namel. The
arguments to the function are in rxfnc_argc and rxfnc_argv. If the named
external function is invoked by the REXX CALL instruction (rather than as a
function call), the flag rxffsub is TRUE.

The exit handler can set rxfnc_flags to indicate the external function success.
If neither rxfferr or rxffnfnd is TRUE, the exit hander successfully called the
external function. The error flags are checked only when the exit handler
handles the the request.

The exit handler sets rxffnfnd to TRUE when the exit handler could not locate
the external function. The interpreter raises REXX error 43, "Routine not
found". The exit handler sets rxfferr to TRUE when the exit handler located the
external function, but the external function returned an error return code. The
REXX interpreter raises error 40, "Invalid call to routine".

The exit handler returns the external function result in the rxfnc_retc
RXSTRING. The REXX interpreter will raise error 44, "Function did not return
data" when the external routine is invoked as a function and the exit handler
does not return a result. When the external routine is invoked by the REXX CALL
instruction, the exit handler a result is not required.


ΓòÉΓòÉΓòÉ 10.4. RXCMD ΓòÉΓòÉΓòÉ

Process subcommand handler calls.

The RXCMD exit has the following subfunction:

RXCMDHST    Call a named subcommand handler.


ΓòÉΓòÉΓòÉ 10.4.1. RXCMDHST ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics - RXCMDHST ΓòÉΓòÉΓòÉ

Call a named subcommand handler.

When called: When a REXX procedure issues a command.

Default action: Call the named subcommand handler specified by the current REXX
ADDRESS setting.

Exit Action: Process the call to a named subcommand handler.

Continuation: Raise the ERROR or FAILURE condition when indicated by the
parameter list flags,

Note:  The variable pool interface function is fully enabled during RXCMD exit
       handler calls.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RXCMDHST ΓòÉΓòÉΓòÉ

typedef struct {
   struct {                            /* Condition flags             */
      unsigned rxfcfail : 1;           /* Command failed.  Trap with  */
                                       /* CALL or SIGNAL on FAILURE.  */
      unsigned rxfcerr  : 1;           /* Command ERROR occurred.     */
                                       /* Trap with CALL or SIGNAL on */
                                       /* ERROR.                      */
   } rxcmd_flags;
   PUCHAR            rxcmd_address;    /* Pointer to address name.    */
   USHORT            rxcmd_addressl;   /* Length of address name.     */
   PUCHAR            rxcmd_dll;        /* dll name for command.       */
   USHORT            rxcmd_dll_len;    /* Length of dll name.  0 ==>  */
                                       /* .EXE file.                  */
   RXSTRING          rxcmd_command;    /* The command string.         */
   RXSTRING          rxcmd_retc;       /* Pointer to return code      */
                                       /* buffer.  User allocated.    */
} RXCMDHST_PARM;

The rxcmd_command field contains the issued command. rxcmd_address,
rxcmd_addressl, rxcmd_dll, and rxcmd_dll_len fully define the current ADDRESS
setting. rxcmd_retc is an RXSTRING for the return code value assigned to REXX
special variable RC.

The exit handler can set rxfcfail or rxfcerr to TRUE to raise an ERROR or
FAILURE condition.


ΓòÉΓòÉΓòÉ 10.5. RXMSQ ΓòÉΓòÉΓòÉ

External data queue exit.

The RXMSQ exit has the following subfunctions:

RXMSQPLL    Pull a line from the external data queue.
RXMSQPSH    Place a line on the external data queue.
RXMSQSIZ    Return the number of lines in the external data queue.
RXMSQNAM    Set the name of the active external data queue.


ΓòÉΓòÉΓòÉ 10.5.1. RXMSQPLL ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics - RXMSQPLL ΓòÉΓòÉΓòÉ

Pull a line from the external data queue.

When called: When a REXX PULL instruction, PARSE PULL instruction, or LINEIN()
built-in function reads a line from the external data queue.

Default action: Remove a line from the current REXX data queue.

Exit Action: Return a line from the exit handler provided data queue.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RXMSQPLL ΓòÉΓòÉΓòÉ

typedef struct {
   RXSTRING          rxmsq_retc;       /* Pointer to dequeued entry   */
                                       /* buffer.  User allocated.    */
} RXMSQPLL_PARM;

The exit handler returns the queue line in the rxmsq_retc RXSTRING.


ΓòÉΓòÉΓòÉ 10.5.2. RXMSQPSH ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics - RXMSQPSH ΓòÉΓòÉΓòÉ

Place a line on the external data queue.

When called: Called by the REXX PUSH instruction, QUEUE instruction, or
LINEOUT() built-in function to add a line to the data queue.

Default action: Add the line to the current REXX data queue.

Exit Action: Add the line to the exit handler provided data queue.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RXMSQPSH ΓòÉΓòÉΓòÉ

typedef struct {
   struct {                            /* Operation flag              */
      unsigned rxfmlifo : 1;           /* Stack entry LIFO when TRUE, */
                                       /* FIFO when FALSE.            */
   } rxmsq_flags;
   RXSTRING          rxmsq_value;      /* The entry to be pushed.     */
} RXMSQPSH_PARM;

The rxmsq_value RXSTRING contains the line added to the queue. It is the
responsibility of the exit handler to truncate the string if the exit handler
data queue has a maximum length restriction. rxfmlifo is the stacking order
(LIFO or FIFO).


ΓòÉΓòÉΓòÉ 10.5.3. RXMSQSIZ ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics - RXMSQSIZ ΓòÉΓòÉΓòÉ

Return the number of lines in the external data queue.

When called: When the REXX QUEUED() built-in function requests the size of the
external data queue.

Default action: Request the size from the current REXX data queue.

Exit Action: Return the size of the exit handler provided data queue.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RXMSQSIZ ΓòÉΓòÉΓòÉ

typedef struct {
   ULONG             rxmsq_size;       /* Number of Lines in Queue    */
} RXMSQSIZ_PARM;

The exit handler returns the number of queue lines in rxmsq_size.


ΓòÉΓòÉΓòÉ 10.5.4. RXMSQNAM ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics - RXMSQNAM ΓòÉΓòÉΓòÉ

Set the name of the active external data queue.

When called: Called by the RXQUEUE("Set",newname) built-in function.

Default action: Change the current default queue to newname.

Exit Action: Change the default queue name for the exit handler provided data
queue.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RXMSQNAM ΓòÉΓòÉΓòÉ

typedef struct {
   RXSTRING          rxmsq_name;       /* RXSTRING containing         */
                                       /* queue name.                 */
} RXMSQNAM_PARM;

rxmsq_name contains the new queue name.


ΓòÉΓòÉΓòÉ 10.6. RXSIO ΓòÉΓòÉΓòÉ

Standard input and output.

The RXMSQ exit has the following subfunctions:

RXSIOSAY    Write a line to the standard output stream (STDOUT).
RXSIOTRC    Write trace and error message output to the standard error stream.
RXSIOTRD    Read from standard input stream.
RXSIODTR    Interactive debug input.

Note:  The PARSE LINEIN instruction and the LINEIN, LINEOUT, LINES, CHARIN,
       CHAROUT, and CHARS built-in functions do not call the RXSIO exit
       handler.


ΓòÉΓòÉΓòÉ 10.6.1. RXSIOSAY ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics - RXSIOSAY ΓòÉΓòÉΓòÉ

Write a line to the standard output stream (STDOUT).

When called: By the SAY instruction to write a line to the standard output
stream.

Default action: Write to the standard output stream.

Exit Action: Write the line to the exit handler provided output stream.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RXSIOSAY ΓòÉΓòÉΓòÉ

typedef struct {
   RXSTRING          rxsio_string;     /* String to display.          */
} RXSIOSAY_PARM;

The output line is contained in rxsio_string. The output line can be any
length. It is the responsibility of the exit handler to truncate or split the
line if necessary.


ΓòÉΓòÉΓòÉ 10.6.2. RXSIOTRC ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics - RXSIOTRC ΓòÉΓòÉΓòÉ

Write trace and error message output to the standard error stream.

When called: To output lines of trace output and REXX error messages.

Default action: Write the line to the standard error stream (STDERR).

Exit Action: Write tine to the exit handler provided error output stream.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RXSIOTRC ΓòÉΓòÉΓòÉ

typedef struct {
  RXSTRING           rxsio_string;     /* Trace line to display.      */
} RXSIOTRC_PARM;

The output line is contained in rxsio_string. The output line can be of any
length. It is the responsibility of the exit handler to truncate or split the
line if necessary.


ΓòÉΓòÉΓòÉ 10.6.3. RXSIOTRD ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics - RXSIOTRD ΓòÉΓòÉΓòÉ

Read from standard input stream.

When called: To read from the standard input stream for the REXX PULL and PARSE
PULL instructions.

Default action: Read a line from the standard input stream (STDIN).

Exit Action: Return a line from the exit handler provided standard input
stream.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RXSIOTRD ΓòÉΓòÉΓòÉ

typedef struct {
   RXSTRING          rxsiotrd_retc;    /* RXSTRING for output.        */
} RXSIOTRD_PARM;

The input stream line is returned in the rxsiotrd_retc RXSTRING.


ΓòÉΓòÉΓòÉ 10.6.4. RXSIODTR ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics - RXSIODTR ΓòÉΓòÉΓòÉ

Interactive debug input.

When called: To read from the debug input stream for interactive debug prompts.

Default action: Read a line from the standard input stream (STDIN).

Exit Action: Return a line from the exit handler provided standard debug
stream.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RXSIODTR ΓòÉΓòÉΓòÉ

typedef struct {
   RXSTRING          rxsiodtr_retc;    /* RXSTRING for output.        */
} RXSIODTR_PARM;

The input stream line is returned in the rxsiodtr_retc RXSTRING.


ΓòÉΓòÉΓòÉ 10.7. RXHLT ΓòÉΓòÉΓòÉ

HALT condition processing.

The RXHLT exit has the following subfunctions:

RXHLTTST    Test HALT indicator.
RXHLTCLR    Clear HALT condition.

Note:  Since the RXHLT exit handler is called after every REXX instruction,
       this exit will slow REXX program execution. The RexxSetHalt function can
       halt a REXX program without between-instruction polling.


ΓòÉΓòÉΓòÉ 10.7.1. RXHLTTST ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics - RXHLTTST ΓòÉΓòÉΓòÉ

Test HALT indicator.

When called: When the interpreter polls externally raised HALT conditions. The
exit is called after completion of every REXX instruction.

Default action: The interpreter uses the system facilities for trapping
Cntrl-Break signals.

Exit Action: Return the current state of the HALT condition (either TRUE or
FALSE).

Continuation: Raise the REXX HALT condition if the exit handler returns TRUE.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RXHLTTST ΓòÉΓòÉΓòÉ

typedef struct {
   struct {                            /* Halt flag                   */
      unsigned rxfhhalt : 1;           /* Set if HALT occurred.       */
   } rxhlt_flags;
} RXHLTTST_PARM;

If the exit handler sets rxfhhalt to TRUE, the HALT condition will be raised in
the REXX program.

When the exit handler has set rxfhhalt to TRUE, it can also use the RXSHV_EXIT
operation of RexxVariablePool to return a string describing the HALT condition
reason. The REXX program can retrieve the reason string using the
CONDITION("D") built-in function.


ΓòÉΓòÉΓòÉ 10.7.2. RXHLTCLR ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics - RXHLTCLR ΓòÉΓòÉΓòÉ

Clear HALT condition.

When called: To acknowledge processing of the HALT condition when the
interpreter has recognized and raised a HALT condition

Default action: The interpreter resets the Cntrl-Break signal handlers.

Exit Action: Reset exit handler HALT state to FALSE.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RXHLTCLR ΓòÉΓòÉΓòÉ

(None)


ΓòÉΓòÉΓòÉ 10.8. RXTRC ΓòÉΓòÉΓòÉ

Test external trace indicator.

The RXTRC exit has the following subfunction:

RXTRCTST    Test external trace indicator.

Note:  Since the RXTST exit is called after every REXX instruction, these exits
       will slow REXX procedure execution. The RexxSetTrace function can turn
       on REXX tracing without between-instruction polling.


ΓòÉΓòÉΓòÉ 10.8.1. RXTRCTST ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics - RXTRCTST ΓòÉΓòÉΓòÉ

Test external trace indicator.

When called: When the interpreter polls poll for an external trace event. The
exit is called after completion of every REXX instruction.

Default action: None.

Exit Action: Return the current state of external tracing (either TRUE or
FALSE).

Continuation: When the exit handler switches from FALSE to TRUE, the REXX
interpreter enters REXX interactive debug mode using TRACE ?R level of tracing.
When the exit handler switches from TRUE to FALSE, the REXX interpreter will
exit interactived debug mode.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RXTRCTST ΓòÉΓòÉΓòÉ

struct rxtrc_parm {
  struct {
    unsigned rxftrace : 1;        /* External trace setting        */
  } rxtrc_flags;
}

If the exit handler switches rxftrace to TRUE, REXX will switch on interactive
debug mode. It the exit handler switches rxftrace to FALSE, REXX will switch
off interactive debug mode.


ΓòÉΓòÉΓòÉ 10.9. RXINI ΓòÉΓòÉΓòÉ

Initialization processing.

The RXINT exit has the following subfunction:

RXINIEXT    Initialization exit.


ΓòÉΓòÉΓòÉ 10.9.1. RXINIEXT ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics - RXINIEXT ΓòÉΓòÉΓòÉ

Initialization exit.

The RXINI exit is called as the last step of REXX program initialization. The
exit handler can perform additional initialization. For example:

o Use RexxVariablePool to initialize application specific variables

o Use RexxSetTrace to switch on REXX interactive debug mode.

When called: Before the first instruction of the REXX procedure is interpreted.

Default action: None.

Exit Action: The exit handler can perform additional initialization. For
example:

   o Use RexxVariablePool to initialize application specific variables

   o Use RexxSetTrace to switch on REXX interactive debug mode.

Note:  The variable pool interface is fully enabled for this exit.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RXINIEXT ΓòÉΓòÉΓòÉ

(None)


ΓòÉΓòÉΓòÉ 10.10. RXTER ΓòÉΓòÉΓòÉ

Termination processing.

The RXTER exit has the following subfunction:

RXTEREXT    Termination exit


ΓòÉΓòÉΓòÉ 10.10.1. RXTEREXT ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics - RXTEREXT ΓòÉΓòÉΓòÉ

Termination exit

the RXTER exit is called as the first step of REXX program termination.

When called: After the last instruction of the REXX procedure has been
interpreted.

Default action: None.

Exit Action: The exit handler can perform additional termination activities For
example, the exit handler can use RexxVariablePool to retrieve REXX variables
values.

Note:  The variable pool interface is fully enabled for this exit.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RXTEREXT ΓòÉΓòÉΓòÉ

(None)


ΓòÉΓòÉΓòÉ 11. System Exit Functions ΓòÉΓòÉΓòÉ

o RexxRegisterExitDll registers an exit handler that resides in a dynalink
  library routine.

o RexxRegisterExitExe registers an exit handler that resides within application
  code.

o RexxDeregisterExit deregisters an exit handler.

o RexxQueryExit queries an exit handler and retrieves saved user information.


ΓòÉΓòÉΓòÉ 11.1. RexxRegisterExitDll ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Return Values
Errors
Notes
Related Functions


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxRegisterExitDll ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxRegisterExitDll registers an       */
/*  exit handler that resides in a         */
/*  dynamic link library routine.          */
/*******************************************/

#define INCL_RXSYSEXIT      /* Exit handler values */

PSZ     name;         /* handler name */
PSZ     library;      /* DLL name     */
PSZ     routine;      /* routine name */
ULONG   rc;           /* Return code  */
ULONG   userdata[2];  /* save userdata*/

rc = RexxRegisterExitDll(name, library, routine,
     userdata, RXEXIT_DROPPABLE);


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxRegisterExitDll ΓòÉΓòÉΓòÉ

RexxRegisterExitDll registers an exit handler that resides in a dynalink
library routine.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxRegisterExitDll ΓòÉΓòÉΓòÉ

RexxRegisterExitDll (ExitName, ModuleName, EntryPoint, UserArea, DropAuth)

Parameters:

EnvName (PSZ) - input
   Address of an ASCIIZ exit handler name.

ModuleName (PSZ) - input
   Address of an ASCIIZ dynamic link library name. ModuleName is the DLL file
   containing the exit handler routine.

EntryPoint (PSZ) - input
   Address of an ASCIIZ dynalink procedure name. EntryPoint is the exit handler
   routine within ModuleName.

UserArea (PUCHAR) - input
   Address of an 8-byte area of user defined information. The 8 bytes addressed
   by UserArea will be saved with the exit handler registration. UserArea can
   be NULL if there is no user information to save. The saved user information
   can be retrieved with the RexxQueryExit function.

DropAuth (ULONG) - input
   The drop authority. DropAuth identifies the processes that can deregister
   the exit handler. The possible DropAuth values are:

   RXEXIT_DROPPABLE
      Any process can deregister the exit handler with RexxDeregisterExit.

   RXEXIT_NONDROP
      Only a thread within the same process as the thread that registered the
      handler can deregister the handler with RexxDeregisterExit.


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxRegisterExitDll ΓòÉΓòÉΓòÉ

RexxRegisterExitDll returns the following values:

0         RXEXIT_OK
10        RXEXIT_DUP
1002      RXEXIT_NOEMEM
1003      RXEXIT_BADTYPE


ΓòÉΓòÉΓòÉ <hidden> Notes - RexxRegisterExitDll ΓòÉΓòÉΓòÉ

EntryPoint can be either a 16-bit or a 32-bit routine. REXX will invoke the
exit handler in the correct addressing mode.


ΓòÉΓòÉΓòÉ <hidden> Related Functions - RexxRegisterExitDll ΓòÉΓòÉΓòÉ

The following functions are related to RexxRegisterExitDll:

RexxRegisterExitExe
RexxDeregisterExit
RexxQueryExit


ΓòÉΓòÉΓòÉ 11.2. RexxRegisterExitExe ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Return Values
Errors
Notes
Related Functions
Examples


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxRegisterExitExe ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxRegisterExitDll registers an       */
/*  exit handler that resides in a         */
/*  dynamic link library routine.          */
/*******************************************/

#define INCL_RXSYSEXITS     /* Exit handler values */

PSZ     name;         /* handler name */
PSZ     library;      /* DLL name     */
PSZ     routine;      /* routine name */
ULONG   rc;           /* Return code  */
ULONG   userdata[2];  /* save userdata*/

rc = RexxRegisterExitDll(name, library, routine,
     userdata, RXEXIT_DROPPABLE);


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxRegisterExitExe ΓòÉΓòÉΓòÉ

RexxRegisterExitExe registers an exit handler that resides within application
code.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxRegisterExitExe ΓòÉΓòÉΓòÉ

RexxRegisterExitExe (EnvName, EntryPoint, UserArea)

Parameters:

EnvName (PSZ) - input
   Address of an ASCIIZ exit handler name.

EntryPoint (PFN) - input
   Address of the exit handler entry point within the application EXE file.

UserArea (PUCHAR) - input
   Address of an 8-byte area of user defined information. The 8 bytes addressed
   by UserArea will be saved with the exit handler registration. UserArea can
   be NULL if there is no user information to save. The user information can be
   retrieved with the RexxQueryExit function.


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxRegisterExitExe ΓòÉΓòÉΓòÉ

RexxRegisterExitExe returns the following values:

0         RXEXIT_OK
10        RXEXIT_DUP
30        RXEXIT_NOTREG
1002      RXEXIT_NOEMEM
1003      RXEXIT_BADTYPE


ΓòÉΓòÉΓòÉ <hidden> Notes - RexxRegisterExitExe ΓòÉΓòÉΓòÉ

If EnvName has the same name as a handler registered with RexxRegisterExitDll,
RexxRegisterExitExe will return RXEXIT_DUP. This is not an error and the new
exit handler has been properly registered.


ΓòÉΓòÉΓòÉ <hidden> Related Functions - RexxRegisterExitExe ΓòÉΓòÉΓòÉ

The following functions are related to RexxRegisterExitExe:

RexxRegisterExitDll
RexxDeregisterExit
RexxQueryExit


ΓòÉΓòÉΓòÉ <hidden> Examples - RexxRegisterExitExe ΓòÉΓòÉΓòÉ

The following example shows the use of RexxRegisterExitExe:

  WORKAREARECORD  *user_info[2];       /* saved user information     */

  user_info[0] = global_workarea;      /* save global work area for  */
  user_info[1] = NULL;                 /* re-entrancy                */

  rc = RexxRegisterExitExe("IO_Exit",  /* register editor handler    */
      &Edit_IO_Exit,                   /* located at this address    */
      user_info);                      /* save global pointer        */


ΓòÉΓòÉΓòÉ 11.3. RexxDeregisterExit ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Return Values
Errors
Notes
Related Functions


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxDeregisterExit ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxDeregisterExit deregisters an       */
/*  exit handler.                          */
/*******************************************/

#define INCL_RXSYSEXIT      /* Exit handler values */

PSZ     name;       /* handler name       */
PSZ     library     /* handler dll        */
ULONG   rc;         /* Return code */

rc = RexxDeregisterExit(name, library);


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxDeregisterExit ΓòÉΓòÉΓòÉ

RexxDeregisterExit deregisters an exit handler.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxDeregisterExit ΓòÉΓòÉΓòÉ

RexxDeregisterExit (EnvName, ModuleName)

Parameters:

EnvName (PSZ) - input
   Address of an ASCIIZ exit handler name.

ModuleName (PSZ) - input
   Address of an ASCIIZ dynamic link library name. ModuleName restricts the
   query to an exit handler within the ModuleName dynamic link library. When
   ModuleName is NULL, RexxDeregisterExit searches the RexxRegisterExitExe exit
   handler list for a handler within the current process. If RexxDeregisterExit
   does not find a RexxRegisterExitExe handler, it will search the
   RexxRegisterExitDll exit handler list.


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxDeregisterExit ΓòÉΓòÉΓòÉ

RexxDeregisterExit returns the following values:

0         RXEXIT_OK
30        RXEXIT_NOTREG
40        RXEXIT_NOCANDROP
1003      RXEXIT_BADTYPE


ΓòÉΓòÉΓòÉ <hidden> Notes - RexxDeregisterExit ΓòÉΓòÉΓòÉ

The handler is removed from the exit handler list.


ΓòÉΓòÉΓòÉ <hidden> Related Functions - RexxDeregisterExit ΓòÉΓòÉΓòÉ

The following functions are related to RexxDeregisterExit:

RexxRegisterExitDll
RexxRegisterExitExe
RexxQueryExit


ΓòÉΓòÉΓòÉ 11.4. RexxQueryExit ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Return Values
Errors
Related Functions
Examples


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxQueryExit ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxQueryExit queries an exit          */
/*  handler and retrieves saved user       */
/*  information.                           */
/*******************************************/

#define INCL_RXSYSEXIT      /* subcommand handler values */

PSZ     name;         /* handler name */
PSZ     library;      /* DLL name     */
ULONG   userdata[2];  /* saved information */
ULONG   rc;         /* Return code */

rc = RexxQueryExit(name, library, userdata);


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxQueryExit ΓòÉΓòÉΓòÉ

RexxQueryExit queries an exit handler and retrieves saved user information.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxQueryExit ΓòÉΓòÉΓòÉ

RexxQueryExit (EnvName, ModuleName, Flag, UserWord)

Parameters:

EnvName (PSZ) - input
   Address of an ASCIIZ exit handler name.

ModuleName (PSZ) - input
   ModuleName restricts the query to an exit handler within the ModuleName
   dynamic link library. When ModuleName is NULL, RexxQueryExit searches the
   RexxRegisterExitExe exit handler list for a handler within the current
   process. If RexxQueryExit does not find a RexxRegisterExitExe handler, it
   will search the RexxRegisterExitDll exit handler list.

Flag (PUSHORT) - output
   Exit handler registration flag. Flag is the EnvName exit handler
   registration status. When RexxQueryExit returns RXEXIT_OK, the EnvName exit
   handler is currently registered. When RexxQueryExit returns RXEXIT_NOTREG,
   the EnvName exit handler is not registered.

Flag (PUSHORT) - output
   Exit handler registration flag. Flag indicates if the EnvName exit handler
   is registered. If Flag is RXEXIT_OK, the EnvName exit handler is not
   registered. If Flag is RXEXIT_NOTREG, the EnvName exit handler is
   registered.

UserWord (PUCHAR) - output
   Address of an 8-byte area to receive the user information saved with
   RexxRegisterExitExe or RexxRegisterExitDll. UserWord can be NULL if the
   saved user information is not required.


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxQueryExit ΓòÉΓòÉΓòÉ

RexxQueryExit returns the following values:

0         RXEXIT_OK
30        RXEXIT_NOTREG
1003      RXEXIT_BADTYPE


ΓòÉΓòÉΓòÉ <hidden> Related Functions - RexxQueryExit ΓòÉΓòÉΓòÉ

The following functions are related to RexxQueryExit:

RexxRegisterExitDll
RexxRegisterExitExe
RexxDeregisterExit


ΓòÉΓòÉΓòÉ <hidden> Examples - RexxQueryExit ΓòÉΓòÉΓòÉ

The following example shows the use of RexxQueryExit:

ULONG Edit_IO_Exit(
  PRXSTRING Command,    /* Command string passed from the caller    */
  PUSHORT   Flags,      /* pointer to short for return of flags     */
  PRXSTRING Retstr)     /* pointer to RXSTRING for RC return        */
{
  WORKAREARECORD  *user_info[2];       /* saved user information     */
  WORKAREARECORD   global_workarea;    /* application data anchor    */
  USHORT           query_flag;         /* flag for handler query     */


  rc = RexxQueryExit("IO_Exit",        /* retrieve application work  */
      NULL,                            /* area anchor from REXX.     */
      &query_flag,
      user_info);

  global_workarea = user_info[0];      /* set the global anchor      */


ΓòÉΓòÉΓòÉ <hidden> System Exit Interface Errors ΓòÉΓòÉΓòÉ

The following are the exit handler function errors.:

RXEXIT_NOEMEM
   There is insufficient memory available to complete this request.

RXEXIT_OK
   An exit function has executed successfully.

RXEXIT_DUP
   A duplicate exit handler name has been successfully registered; there is
   either:

   o an EXE handler with the same name registered in another process, or

   o a DLL handler with the same name registered in another DLL; to address
     this exit, its library name must be specified.

RXEXIT_NOTREG
   This indicates:

   o registration was unsuccessful due to duplicate handler and dynalink names
     (RexxRegisterExitExe or RexxRegisterExitDll)

   o the exit handler is not registered (other REXX exit functions).

RXEXIT_NOCANDROP
   The exit handler has been registered as "not droppable".


ΓòÉΓòÉΓòÉ 12. Variable Pool Interface ΓòÉΓòÉΓòÉ

Application programs can use the REXX Variable Pool Interface to manipulate the
variables of a currently active REXX procedure.


ΓòÉΓòÉΓòÉ 12.1. Interface Types ΓòÉΓòÉΓòÉ

Three of the Variable Pool Interface functions (set, fetch and drop) have dual
interfaces.


ΓòÉΓòÉΓòÉ 12.1.1. Symbolic Interface ΓòÉΓòÉΓòÉ

The symbolic interface uses normal REXX variable rules when interpreting
variables. Variable names are valid REXX symbols (in mixed case if desired)
including compound symbols. Compound symbols will be referenced with tail
substitution. The functions that use the symbolic interface are RXSHV_SYSET,
RXSHV_SYFET, and RXSHV_SYDRO.


ΓòÉΓòÉΓòÉ 12.1.2. Direct Interface ΓòÉΓòÉΓòÉ

The direct interface uses no substitution or case translation. Simple symbols
must be valid REXX variable names. A valid REXX variable name:

o Does not begin with a digit or period

o Contains only uppercase A to Z, the digits 0 - 9, or the characters _, ! or ?
  before the first period of the name.

o Can contain any characters after the first period of the name.

Compound variables are specified using the derived name of the variable.  Any
characters (including blanks) can appear after the first period of the name. No
additional variable sustitution is used. The direct interface is used by
RXSHV_SET, RXSHV_FETCH, and RXSHV_DROP.


ΓòÉΓòÉΓòÉ 12.2. RexxVariablePool Restrictions ΓòÉΓòÉΓòÉ

Only the main thread of an application can access the REXX variable pool.
Applications can create and use new threads, but only the original thread that
called the RexxStart function can use RexxVariablePool.

OS/2* operating system EXE modules invoked from a REXX procedure execute in a
new process. Because the modules are not using the same process and thread as
the REXX procedure, the modules cannot use RexxVariablePool to access REXX
variables. RexxVariablePool can be used from subcommand handlers, external
functions and exit handlers.


ΓòÉΓòÉΓòÉ 13. RexxVariablePool Interface Function ΓòÉΓòÉΓòÉ

REXX procedure variables are accessed using the RexxVariablePool function.


ΓòÉΓòÉΓòÉ 13.1. RexxVariablePool ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Data Structures
Return Values
Notes
Examples


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxVariablePool ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxVariablePool accesses variables   */
/*  of a currently active REXX procedure.  */
/*******************************************/

#define INCL_RXSHV    /* Shared variable values */

SHVBLOCK  request;    /* request block */
ULONG     rc;         /* Return code */

rc = RexxVariablePool(&request);


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxVariablePool ΓòÉΓòÉΓòÉ

RexxVariablePool accesses variables of a currently active REXX procedure.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxVariablePool ΓòÉΓòÉΓòÉ

RexxVariablePool (RequestBlockList)

Parameters:

RequestBlockList (PSHVBLOCK) - input
   A linked list of shared variable request blocks (SHVBLOCK). Each shared
   variable request block in the linked list is a separate variable access
   request.


ΓòÉΓòÉΓòÉ <hidden> Data Structures - RexxVariablePool ΓòÉΓòÉΓòÉ

typedef struct shvnode {
    struct shvnode    *shvnext;
    RXSTRING           shvname;
    RXSTRING           shvvalue;
    ULONG              shvnamelen;
    ULONG              shvvaluelen;
    UCHAR              shvcode;
    UCHAR              shvret;
}   SHVBLOCK;

Where:

shvnext
   The address of the next SHVBLOCK in the request list. shvnext is NULL for
   the last request block.

shvcode
   The shared variable block request code. The request codes are:

   RXSHV_SET

   RXSHV_SYSET
      Assign a new value to a REXX procedure variable.

   RXSHV_FETCH

   RXSHV_SYFETCH
      Retrieve the value of a REXX procedure variable.

   RXSHV_DROPV

   RXSHV_SYDRO
      Drop (unassign) a REXX procedure variable.

   RXSHV_PRIV
      Fetch REXX procedure private information. The following information items
      can be retrieved by name:

      PARM
         The number of arguments supplied to the REXX procedure. The number
         will be formatted as a character string.

      PARM.n
         The Nth argument string to the REXX procedure. If the Nth argument was
         not supplied to the procedure (either omitted or fewer than N
         parameters were specified), a null string will be returned.

      QUENAME
         The current REXX data queue name.

      SOURCE
         The REXX procedure source string used for the PARSE SOURCE
         instruction.

      VERSION
         The REXX interpreter version string used for the PARSE SOURCE
         instruction.

   RXSHV_NEXTV
      Fetch next variable. RXSHV_NEXTV traverses the variables in the current
      generation of REXX variables, excluding variables hidden by PROCEDURE
      instructions. The variables will not be returned in any specified order.

      The REXX interpreter maintains an internal pointer to its list of
      variables. The variable pointers is reset to the first REXX variable
      whenever: c.

       1. An external program returns control to the interpreter

       2. A set, fetch or drop RexxVariablePool function is used.

      RXSHV_NEXTV returns both the name and the value of REXX variables until
      the end of the variable list is reached. If no REXX variables are left to
      return, RexxVariablePool will set the RXSHV_LVAR bit in shvret.

   RXSHV_EXIT
      Set a return value for an external function or exit handler. RXSHV_EXIT
      is only valid from external functions or exit events that return a string
      value. RXSHV_EXIT can only be used once by an external function or exit
      handler.

shvret
   Individual shared variable request return code. shvret is a 1-byte field of
   status flags for the individual shared variable request. The shvret fields
   for all request blocks in the list are ORed together to form the
   RexxVariablePool return code. The individual status conditions are:

   RXSHV_OK
      The request was processed with out error (all flag bits are FALSE).

   RXSHV_NEWV
      The named variable was uninitialized.

   RXSHV_LVAR
      No more variables are available for an RXSHV_NEXTV operation.

   RXSHV_TRUNC
      A variable value or variable name was truncated because the supplied
      RXSTRING was too small for the copied value.

   RXSHV_BADN
      The variable name specified in shvname was invalid for the requested
      operation.

   RXSHV_MEMFL
      The REXX interpreter was unable to obtain the storage required to
      complete the request.

   RXSHV_BADF
      The shared variable request block contains an invalid function code.

shvname
   An RXSTRING containing a REXX variable name. shvname usage varies for the
   different SHVBLOCK request codes:

   RXSHV_SET

   RXSHV_SYSET

   RXSHV_FETCH

   RXSHV_SYFET

   RXSHV_DROPV

   RXSHV_SYDRO

   RXSHV_PRIV
      shvname is an RXSTRING pointing to the name of the REXX variable accessed
      by the shared variable request block.

   RXSHV_NEXTV
      shvname is an RXSTRING defining an area of storage to receive the name of
      the next variable. shvnamelen is the length of the RXSTRING area. If the
      variable name is longer than shvnamelen characters, the name will be
      truncated and the RXSHV_TRUNC bit of shvret will be set. On return,
      shvname.strlength will contain the length of the variable name;
      shvnamelen will be unchanged.

      If shvname is an empty RXSTRING (strptr is NULL), the REXX interpreter
      will allocate and return an RXSTRING to hold the variable name. If the
      REXX interpreter allocates the RXSTRING, an RXSHV_TRUNC condition cannot
      occur. However, RXSHV_MEMFL errors are possible for these operations. If
      an RXSHV_MEMFL condition occurs, memory will not be allocated for that
      request block. The RexxVariablePool function caller must release the
      storage with "DosFreeMem".

      Note:  The RexxVariablePool does not add a terminating null character to
             the variable name.

   RXSHV_EXIT
      shvname is unused for the RXSHV_EXIT function.

shvvalue
   An RXSTRING containing a REXX variable value. shvvalue meaning varies for
   the different SHVBLOCK request codes:

   RXSHV_SET

   RXSHV_SYSET
      shvvalue is the value assigned to the REXX variable in shvname.
      shvvaluelen contains the length of the variable value.

   RXSHV_EXIT
      shvvalue is the value assigned to the exit handler return value.
      shvvaluelen contains the length of the variable value.

   RXSHV_FETCH

   RXSHV_SYFET

   RXSHV_PRIV

   RXSHV_NEXT
      shvvalue is a buffer the REXX interpreter uses to return a copy of REXX
      variable shvname. shvvaluelen contains the length of the value buffer. On
      return, shvvalue.strlength will be set to the length of the returned
      value and shvvaluelen will be unchanged. If the variable value is longer
      than shvvaluelen characters, the value will be truncated and the
      RXSHV_TRUNC bit of shvret will be set. On return, shvvalue.strlength will
      be set to the length of the returned value; shvvaluelen will be
      unchanged.

      If shvvalue is an empty RXSTRING (strptr is NULL), the REXX interpreter
      will allocate and return an RXSTRING to hold the variable value. If the
      REXX interpreter allocates the RXSTRING, an RXSHV_TRUNC condition cannot
      occur. However, RXSHV_MEMFL errors are possible for these operations. If
      an RXSHV_MEMFL condition occurs, memory will not be allocated for that
      request block. The RexxVariablePool function caller must release the
      storage with "DosFreeMem".

      Note:  RexxVariablePool does not add a terminating null character to the
             variable value.

   RXSHV_DROPV

   RXSHV_SYDRO
      shvvalue is not used.


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxVariablePool ΓòÉΓòÉΓòÉ

RexxVariablePool returns the following values:

0 to 127
   RexxVariablePool has processed the entire shared variable request block
   list.

   The RexxVariablePool function return code is a composite return code for the
   entire set of shared variable requests. The low-order 6 bits of the the
   shvret fields for all request blocks are ORed together to form the composite
   return code. Individual shared variable request status flags are returned in
   the shared variable request block shvret field.

RXSHV_NOAVL
   The variable pool interface was not enabled.


ΓòÉΓòÉΓòÉ <hidden> Notes - RexxVariablePool ΓòÉΓòÉΓòÉ

The REXX interpreter processes each request block in the order provided; the
RexxVariablePool function returns when the last block is processed or after a
severe error (such as an out-of-memory condition).

The RexxVariablePool function return code is a composite return code for the
entire set of shared variable requests. The return codes for all of the
individual requests are ORed together to form the composite return code.
Individual shared variable request return code are returned in the request
shared variable blocks.


ΓòÉΓòÉΓòÉ <hidden> Examples - RexxVariablePool ΓòÉΓòÉΓòÉ

/*********************************************************************/
/*                                                                   */
/* SetRexxVariable - Set the value of a REXX variable                */
/*                                                                   */
/*********************************************************************/

INT SetRexxVariable(
  PSZ        name,                     /* REXX variable to set       */
  PSZ        value);                   /* value to assign            */
{
  SHVBLOCK   block;                    /* variable pool control block*/

  block.shvcode = RXSHV_SYSET;         /* do a symbolic set operation*/
  block.shvret=(UCHAR)0;               /* clear return code field    */
  block.shvnext=(PSHVBLOCK)0;          /* no next block              */
                                       /* set variable name string   */
  MAKERXSTRING(block.shvname, name, strlen(name));
                                       /* set value string           */
  MAKERXSTRING(block.shvvalue, value, strlen(value));
  block.shvvaluelen=strlen(value);     /* set value length           */
  return RexxVariablePool(&block);     /* set the variable           */
}


ΓòÉΓòÉΓòÉ 14. Halt and Trace Interface ΓòÉΓòÉΓòÉ

The halt and trace functions raise a REXX HALT condition or change the REXX
interactive debug mode while a REXX procedure is running. These interfaces may
be preferred over the RXHLT and RXTRC system exits. The REXX calls the RXTRC
exit handler after each REXX instruction completes. This might cause a
noticable performance degradation. The Halt and Trace functions are a single
request to change the halt or trace state, and do not degrade the REXX
procedure performance.

o RexxSetHalt raises a HALT condition in a running REXX program.

o RexxSetTrace turns on interactive debug mode for a REXX procedure.

o RexxResetTrace turns off interactive debug mode for a REXX procedure.


ΓòÉΓòÉΓòÉ 15. Halt and Trace Functions ΓòÉΓòÉΓòÉ

o RexxSetHalt raises a HALT condition in a running REXX program.

o RexxSetTrace turns on interactive debug mode for a REXX procedure.

o RexxResetTrace turns off interactive debug mode for a REXX procedure.


ΓòÉΓòÉΓòÉ 15.1. RexxSetHalt ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Return Values
Notes


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxSetHalt ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxSetHalt raises a HALT condition    */
/*  in a running REXX program.             */
/*******************************************/

#define INCL_RXARI     /* Halt and Trace values */

TID     ThreadId;   /* Thread of REXX program  */
PID     ProcessId;  /* Process of REXX program */
ULONG   rc;         /* Return code             */

rc = RexxSetHalt(ProcessId, ThreadId);


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxSetHalt ΓòÉΓòÉΓòÉ

RexxSetHalt raises a HALT condition in a running REXX program.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxSetHalt ΓòÉΓòÉΓòÉ

RexxSetHalt (ProcessId, ThreadId)

Parameters:

ProcessId (PID) - input
   The process ID of the target REXX procedure. ProcessId is the application
   process that called the RexxStart function.

ThreadId (TID) - input
   The thread ID of the target REXX procedure. ThreadId is the application
   thread that called the RexxStart function.


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxSetHalt ΓòÉΓòÉΓòÉ

RexxSetHalt returns the following values:

0         RXARI_OK
1         RXARI_PID_TID_NOT_FOUND
2         RXARI_PROCESSING_ERROR


ΓòÉΓòÉΓòÉ <hidden> Notes - RexxSetHalt ΓòÉΓòÉΓòÉ

This function will not be processed if the target REXX program is executing
with the RXHLT exit enabled.


ΓòÉΓòÉΓòÉ <hidden> Related Functions - RexxSetHalt ΓòÉΓòÉΓòÉ

The following functions are related to RexxSetHalt:

RexxSetTrace
RexxResetTrace


ΓòÉΓòÉΓòÉ 15.2. RexxSetTrace ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Return Values
Notes


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxSetTrace ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxSetTrace turns on interactive      */
/*  debug mode for REXX procedure.         */
/*******************************************/

#define INCL_RXARI     /* Halt and Trace values */

TID     ThreadId;   /* Thread of REXX program  */
PID     ProcessId;  /* Process of REXX program */
ULONG   rc;         /* Return code             */

rc = RexxSetTrace(ProcessId, ThreadId);


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxSetTrace ΓòÉΓòÉΓòÉ

RexxSetTrace turns on interactive debug mode for a REXX procedure.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxSetTrace ΓòÉΓòÉΓòÉ

RexxSetTrace (ProcessId, ThreadId)

Parameters:

ProcessId (PID) - input
   The process ID of the target REXX procedure. ProcessId is the application
   process that called the RexxStart function.

ThreadId (TID) - input
   The thread ID of the target REXX procedure. ThreadId is the application
   thread that called the RexxStart function.


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxSetTrace ΓòÉΓòÉΓòÉ

RexxSetTrace returns the following values:

0         RXARI_OK
1         RXARI_PID_TID_NOT_FOUND
2         RXARI_PROCESSING_ERROR


ΓòÉΓòÉΓòÉ <hidden> Notes - RexxSetTrace ΓòÉΓòÉΓòÉ

The RexxSetTrace function is not processed if the REXX procedure is using the
RXTRC exit.


ΓòÉΓòÉΓòÉ <hidden> Related Functions - RexxSetTrace ΓòÉΓòÉΓòÉ

The following functions are related to RexxSetTrace:

RexxSetHalt
RexxResetTrace


ΓòÉΓòÉΓòÉ 15.3. RexxResetTrace ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Return Values
Notes


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxResetTrace ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxResetTrace turns off interactive   */
/*  debug mode for REXX procedure.         */
/*******************************************/

#define INCL_RXARI     /* Halt and Trace values */

TID     ThreadId;   /* Thread of REXX program  */
PID     ProcessId;  /* Process of REXX program */
ULONG   rc;         /* Return code             */

rc = RexxResetTrace(ProcessId, ThreadId);


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxResetTrace ΓòÉΓòÉΓòÉ

RexxResetTrace turns off interactive debug mode for a REXX procedure.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxResetTrace ΓòÉΓòÉΓòÉ

RexxResetTrace (ProcessId,ThreadId)

Parameters:

ProcessId (PID) - input
   The process ID of the target REXX procedure. ProcessId is the application
   process that called the RexxStart function.

ThreadId (TID) - input
   The thread ID of the target REXX procedure. The thread ID of the target REXX
   procedure. ThreadId is the application thread that called the RexxStart
   function.


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxResetTrace ΓòÉΓòÉΓòÉ

RexxResetTrace returns the following values:

0         RXARI_OK
1         RXARI_PID_TID_NOT_FOUND
2         RXARI_PROCESSING_ERROR


ΓòÉΓòÉΓòÉ <hidden> Notes - RexxResetTrace ΓòÉΓòÉΓòÉ

The RexxResetTrace function is not processed if the REXX procedure is using the
RXTRC exit.

Interactive debug will not be turned off unless interactive debug mode was
originally started with RexxSetTrace.


ΓòÉΓòÉΓòÉ <hidden> Related Functions - RexxResetTrace ΓòÉΓòÉΓòÉ

The following functions are related to RexxResetTrace:

RexxSetHalt
RexxSetTrace


ΓòÉΓòÉΓòÉ 16. Macrospace Interface ΓòÉΓòÉΓòÉ

The macrospace can improve the performance of REXX procedures by maintaining
REXX procecure images in memory for immediate load and execution. This is
useful for frequently used procedures and functions such as editor macros.

Programs registered in the REXX macrospace are available to all processes. They
can be executed using the RexxStart function or called as functions or
subroutines from other REXX procedures.

Macrospace procedures are called as other REXX external functions are called.
However, the macrospace REXX procedures can be placed at the front or at the
end of the external function search order.

REXX procedures in the macrospace can be saved to a disk file. A saved
macrospace file can be reloaded with the RexxLoadMacroSpace function. An
application, such as an editor, can create a library of frequently-used
functions and load the library into the macrospace for fast access. Multiple
macrospace libraries can be created and loaded.
Search Order

When RexxAddMacro loads a REXX procecure into the macrospace, the position in
the external function search order is specified. The REXX procedure can be
placed before all other forms of external function or after all other external
functions.

RXMACRO_SEARCH_BEFORE A function registered with RXMACRO_SEARCH_BEFORE will be
          located by the REXX interpreter before any registered functions or
          external REXX files.

SEARCH_AFTER Function Registration A function registered with
          RXMACRO_SEARCH_AFTER will be located by the REXX interpreter after
          any registered functions or external REXX files.

Storage of Macrospace Libraries

Note:  The REXX macrospace is placed in shared memory. The size of the
       macrospace is only limited by the amount of memory and swap space
       available to the system. However, as the macrospace grows, it limits the
       memory available to other processes in the system. Allowing the
       macrospace to grow too large might degrade overall system performance
       due to increased system swap file access. It is recommended that only
       the most frequently used functions be placed in the macrospace.


ΓòÉΓòÉΓòÉ 17. Macrospace Interface Functions ΓòÉΓòÉΓòÉ

o RexxAddMacro loads a REXX procedure into the macrospace.

o RexxDropMacro removes a REXX procedure from the macrospace.

o RexxClearMacroSpace removes all loaded REXX procedures from the macrospace.

o RexxSaveMacroSpace saves all or part of the macrospace REXX procedures

o RexxLoadMacroSpace loads all or part of the REXX procedures from a saved
  macrospace file.

o RexxQueryMacro searches the macrospace for a specified function.

o RexxReorderMacro changes the search order position of a loaded macrospace


ΓòÉΓòÉΓòÉ 17.1. RexxAddMacro ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Return Values
Errors
Related Functions
Examples


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxAddMacro ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxAddMacro loads a REXX procedure    */
/*  into the macrospace.                   */
/*******************************************/

#define INCL_RXMACRO    /* Macrospace values */

PSZ     name;       /* function name      */
PSZ     file;       /* REXX source file   */
ULONG   rc;         /* Return code        */

rc = RexxAddMacro(name, file, RXMACRO_SEARCH_BEFORE);


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxAddMacro ΓòÉΓòÉΓòÉ

RexxAddMacro loads a REXX procedure into the macrospace.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxAddMacro ΓòÉΓòÉΓòÉ

RexxAddMacro (FuncName, SourceFile, Position)

Parameters:

FuncName (PSZ) - input

   Address of the ASCIIZ function name. Macrospace REXX procedures are called
   using FuncName.

SourceFile (PSZ) - input
   Address of the ASCIIZ file specification for the REXX procedure source file.
   When a file extension is not supplied, .CMD is used. When the full path is
   not specified, the current directory and path is searched.

Position (ULONG) - input
   Position in the REXX external function search order. Possible values are:

   RXMACRO_SEARCH_BEFORE
      The function will be located by the REXX interpreter before any
      registered functions or external REXX files.

   RXMACRO_SEARCH_AFTER
      The function will be located by the REXX interpreter after any registered
      functions or external REXX files.


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxAddMacro ΓòÉΓòÉΓòÉ

RexxAddMacro returns the following values:

0         RXMACRO_OK
1         RXMACRO_NO_STORAGE
7         RXMACRO_SOURCE_NOT_FOUND
8         RXMACRO_INVALID_POSITION


ΓòÉΓòÉΓòÉ <hidden> Related Functions - RexxAddMacro ΓòÉΓòÉΓòÉ

The following functions are related to RexxAddMacro:

RexxDropMacro
RexxClearMacroSpace
RexxSaveMacroSpace
RexxLoadMacroSpace
RexxQueryMacro
RexxReorderMacro


ΓòÉΓòÉΓòÉ 17.2. RexxDropMacro ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Return Values
Errors
Related Functions


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxDropMacro ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxDropMacro removes a REXX           */
/*  procedure from the macrospace.         */
/*******************************************/

#define INCL_RXMACRO    /* Macrospace values */

PSZ     name;       /* function name      */
ULONG   rc;         /* Return code        */

rc = RexxDropMacro(name);


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxDropMacro ΓòÉΓòÉΓòÉ

RexxDropMacro removes a REXX procedure from the macrospace.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxDropMacro ΓòÉΓòÉΓòÉ

RexxDropMacro (FuncName)

Parameters:

FuncName (PSZ) - input
   Address of the ASCIIZ function name.


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxDropMacro ΓòÉΓòÉΓòÉ

RexxDropMacro returns the following values:

0         RXMACRO_OK
2         RXMACRO_NOT_FOUND


ΓòÉΓòÉΓòÉ <hidden> Related Functions - RexxDropMacro ΓòÉΓòÉΓòÉ

The following functions are related to RexxDropMacro:

RexxAddMacro
RexxClearMacroSpace
RexxSaveMacroSpace
RexxLoadMacroSpace
RexxQueryMacro
RexxReorderMacro


ΓòÉΓòÉΓòÉ 17.3. RexxClearMacroSpace ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Return Values
Errors
Notes
Related Functions


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxClearMacroSpace ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxClearMacroSpace removes all        */
/*  REXX procedures from the macrospace    */
/*******************************************/

#define INCL_RXMACRO    /* Macrospace values */

ULONG   rc;         /* Return code        */

rc = RexxClearMacroSpace();


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxClearMacroSpace ΓòÉΓòÉΓòÉ

RexxClearMacroSpace removes all loaded REXX procedures from the macrospace.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxClearMacroSpace ΓòÉΓòÉΓòÉ

RexxClearMacroSpace ()

Parameters:

(None)


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxClearMacroSpace ΓòÉΓòÉΓòÉ

RexxClearMacroSpace returns the following values:

0         RXMACRO_OK
2         RXMACRO_NOT_FOUND


ΓòÉΓòÉΓòÉ <hidden> Notes - RexxClearMacroSpace ΓòÉΓòÉΓòÉ

RexxClearMacroSpace must be used with care. This function will remove all
functions from the macrospace, including functions loaded by other processes.


ΓòÉΓòÉΓòÉ <hidden> Related Functions - RexxClearMacroSpace ΓòÉΓòÉΓòÉ

The following functions are related to RexxClearMacroSpace:

RexxAddMacro
RexxDropMacro
RexxSaveMacroSpace
RexxLoadMacroSpace
RexxQueryMacro
RexxReorderMacro


ΓòÉΓòÉΓòÉ 17.4. RexxSaveMacroSpace ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Return Values
Errors
Notes
Related Functions
Examples


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxSaveMacroSpace ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxSaveMacroSpace saves all or part   */
/*  of the macrospace REXX procedures      */
/*******************************************/

#define INCL_RXMACRO    /* Macrospace values */

PSZ     macrolist;  /* list of macros     */
ULONG   count;      /* size of macrolist  */
PSZ     file;       /* name of savefile   */
ULONG   rc;         /* Return code        */

rc = RexxSaveMacroSpace(count, macrolist, file);


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxSaveMacroSpace ΓòÉΓòÉΓòÉ

RexxSaveMacroSpace saves all or part of the macrospace REXX procedures to a
disk file.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxSaveMacroSpace ΓòÉΓòÉΓòÉ

RexxSaveMacroSpace (FuncCount, FuncNames, MacroLibFile)

Parameters:

FuncCount (ULONG) - input
   Number of REXX procedures to save.

FuncNames (PSZ *) - input
   Address of a list of ASCIIZ function names. FuncCount gives the size of the
   function list.

MacroLibFile (PSZ) - input
   Address of the ASCIIZ macrospace file name. If MacroLibFile already exists,
   it is replaced with the new file.


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxSaveMacroSpace ΓòÉΓòÉΓòÉ

RexxSaveMacroSpace returns the following values:

0         RXMACRO_OK
2         RXMACRO_NOT_FOUND
3         RXMACRO_EXTENSION_REQUIRED
5         RXMACRO_FILE_ERROR


ΓòÉΓòÉΓòÉ <hidden> Notes - RexxSaveMacroSpace ΓòÉΓòÉΓòÉ

When FuncCount is 0 or FuncNames is NULL, RexxSaveMacroSpace saves all
functions in the macrospace.

Saved macrospace files can only be used with the same interpreter version that
created the images. If the RexxLoadMacroSpace function is called to load a
saved macrospace, and the release level or service level is incorrect, the
RexxLoadMacroSpace function will fail. If RexxLoadMacroSpace fails, the REXX
procedures must be reloaded individually from the original source programs.


ΓòÉΓòÉΓòÉ <hidden> Related Functions - RexxSaveMacroSpace ΓòÉΓòÉΓòÉ

The following functions are related to RexxSaveMacroSpace:

RexxAddMacro
RexxDropMacro
RexxClearMacroSpace
RexxLoadMacroSpace
RexxQueryMacro
RexxReorderMacro


ΓòÉΓòÉΓòÉ 17.5. RexxLoadMacroSpace ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Return Values
Errors
Notes
Related Functions
Examples


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxLoadMacroSpace ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxLoadMacroSpace loads all or part   */
/*  of the REXX procedures from a saved    */
/*  macrospace file.                       */
/*******************************************/

#define INCL_RXMACRO    /* Macrospace values */

PSZ     macrolist;  /* list of macros     */
ULONG   count;      /* size of macrolist  */
PSZ     file;       /* name of savefile   */
ULONG   rc;         /* Return code        */

rc = RexxLoadMacroSpace(count, macrolist, file);


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxLoadMacroSpace ΓòÉΓòÉΓòÉ

RexxLoadMacroSpace loads all or part of the REXX procedures from a saved
macrospace file.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxLoadMacroSpace ΓòÉΓòÉΓòÉ

RexxLoadMacroSpace (FuncCount, FuncNames, MacroLibFile)

Parameters:

FuncCount (ULONG) - input
   Number of REXX procedures to load from the saved macrospace.

FuncNames (PSZ *) - input
   Address of a list of ASCIIZ REXX function names. FuncCount gives the size of
   the function list.

MacroLibFile (PSZ) - input
   Address of the ASCIIZ saved macrospace file name.


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxLoadMacroSpace ΓòÉΓòÉΓòÉ

RexxLoadMacroSpace returns the following values:

0         RXMACRO_OK
1         RXMACRO_NO_STORAGE
2         RXMACRO_NOT_FOUND
4         RXMACRO_ALREADY_EXISTS
5         RXMACRO_FILE_ERROR
6         RXMACRO_SIGNATURE_ERROR


ΓòÉΓòÉΓòÉ <hidden> Notes - RexxLoadMacroSpace ΓòÉΓòÉΓòÉ

When FuncCount is 0 or FuncNames is NULL, RexxLoadMacroSpace loads all REXX
procedures from the saved file.

If the RexxLoadMacroSpace function must replace an existing macrospace REXX
procedure, the entire load request is discarded and the macrospace remains
unchanged.


ΓòÉΓòÉΓòÉ <hidden> Related Functions - RexxLoadMacroSpace ΓòÉΓòÉΓòÉ

The following functions are related to RexxLoadMacroSpace:

RexxAddMacro
RexxDropMacro
RexxClearMacroSpace
RexxSaveMacroSpace
RexxQueryMacro
RexxReorderMacro


ΓòÉΓòÉΓòÉ 17.6. RexxQueryMacro ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Return Values
Errors
Related Functions
Examples


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxQueryMacro ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxQueryMacro searches the            */
/*  macrospace for a specified function.   */
/*******************************************/

#define INCL_RXMACRO    /* Macrospace values */

PSZ     name;       /* function name         */
USHORT  position;   /* search order position */
ULONG   rc;         /* Return code           */

rc = RexxQueryMacro(name, &position);


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxQueryMacro ΓòÉΓòÉΓòÉ

RexxQueryMacro searches the macrospace for a specified function.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxQueryMacro ΓòÉΓòÉΓòÉ

RexxQueryMacro (FuncName, Position)

Parameters:

FuncName (PSZ) - input
   Address of an ASCIIZ function name.

Position (PUSHORT) - output
   Address of an unsigned short integer flag. If the function is loaded in the
   macrospace, Position is set to the current function search-order position.


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxQueryMacro ΓòÉΓòÉΓòÉ

RexxQueryMacro returns the following values:

0         RXMACRO_OK
2         RXMACRO_NOT_FOUND


ΓòÉΓòÉΓòÉ <hidden> Related Functions - RexxQueryMacro ΓòÉΓòÉΓòÉ

The following functions are related to RexxQueryMacro:

RexxAddMacro
RexxDropMacro
RexxClearMacroSpace
RexxSaveMacroSpace
RexxLoadMacroSpace
RexxReorderMacro


ΓòÉΓòÉΓòÉ 17.7. RexxReorderMacro ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

Call Syntax
Uses
Parameters
Return Values
Errors
Related Functions


ΓòÉΓòÉΓòÉ <hidden> Call Syntax - RexxReorderMacro ΓòÉΓòÉΓòÉ

/*******************************************/
/* RexxReorderMacro changes the search    */
/*  order position of a loaded macrospace  */
/*  function.                              */
/*******************************************/

#define INCL_RXMACRO    /* Macrospace values */

PSZ     name;       /* function name         */
ULONG   rc;         /* Return code           */

rc = RexxReorderMacro(name, RXMACRO_SEARCH_AFTER);


ΓòÉΓòÉΓòÉ <hidden> Uses - RexxReorderMacro ΓòÉΓòÉΓòÉ

RexxReorderMacro changes the search order position of a loaded macrospace
function.


ΓòÉΓòÉΓòÉ <hidden> Parameters - RexxReorderMacro ΓòÉΓòÉΓòÉ

RexxReorderMacro (FuncName, Position)

Parameters:

FuncName (PSZ) - input
   Address of an ASCIIZ macrospace function name.

Position (ULONG) - input

   New search-order position of the macrospace function. Possible values are:

   RXMACRO_SEARCH_BEFORE
      The function will be located by the REXX interpreter before any
      registered functions or external REXX files.

   RXMACRO_SEARCH_AFTER
      The function will be located by the REXX interpreter after any registered
      functions or external REXX files.


ΓòÉΓòÉΓòÉ <hidden> Return Values - RexxReorderMacro ΓòÉΓòÉΓòÉ

RexxReorderMacro returns the following values:

0         RXMACRO_OK
2         RXMACRO_NOT_FOUND
8         RXMACRO_INVALID_POSITION


ΓòÉΓòÉΓòÉ <hidden> Related Functions - RexxReorderMacro ΓòÉΓòÉΓòÉ

The following functions are related to RexxReorderMacro:

RexxAddMacro
RexxDropMacro
RexxClearMacroSpace
RexxSaveMacroSpace
RexxLoadMacroSpace
RexxQueryMacro


ΓòÉΓòÉΓòÉ <hidden> Macrospace Interface Errors ΓòÉΓòÉΓòÉ

The follow return codes can be returned from the macrospace functions.  These
values signify the causes for a failure, in these functions.

RXMACRO_OK
   The function completed successfully

RXMACRO_NO_STORAGE
   There was not enough memory to complete the requested function.

RXMACRO_NOT_FOUND
   The requested procedure was not found in the macrospace.

RXMACRO_EXTENSION_REQUIRED
   An extension is required for the macrospace file name.

RXMACRO_ALREADY_EXISTS
   Duplicate functions cannot be loaded from a macrospace file.

RXMACRO_FILE_ERROR
   An error occurred accessing a macro space file.

RXMACRO_SIGNATURE_ERROR
   A macrospace save file does not contain valid function images.

RXMACRO_SOURCE_NOT_FOUND
   The requested file was not found.

RXMACRO_INVALID_POSITION
   An invalid search-order position request flag was used.


ΓòÉΓòÉΓòÉ <hidden> Examples - RexxReorderMacro ΓòÉΓòÉΓòÉ

The following example shows the use of RexxAddMacro, RexxQueryMacro,
RexxLoadMacroSpace, and RexxSaveMacroSpace.

                                       /* first load entire package  */
  RexxLoadMacroSpace(0, NULL, "EDITOR.MAC");

  for (i = 0; i < MACRO_COUNT; i++) {  /* verify each macro          */
                                       /* if not there               */
    if (RexxQueryMacro(macro[i], &position))
                                       /* add to list                */
      RexxAddMacro(macro[i], macro_files[i],
          RXMACRO_SEARCH_BEFORE);
  }
                                       /* rebuild the macrospace     */
  RexxSaveMacroSpace(0, NULL, "EDITOR.MAC");

.
.
.

                                       /* build the argument string  */
  MAKERXSTRING(argv[0], macro_argument,
      strlen(macro_argument));
                                       /* set up default return      */
  MAKERXSTRING(retstr, return_buffer, sizeof(return_buffer));
                                       /* set up for macrospace call */
  MAKERXSTRING(macrospace[0],NULL, 0);
  MAKERXSTRING(macrospace[1],NULL, 0);

  return_code = RexxStart(1,           /* one argument               */
                          argv,        /* argument array             */
                          macro[pos],  /* REXX procedure name        */
                          macrospace,  /* use macrospace version     */
                          "Editor",    /* default address name       */
                          RXCOMMAND,   /* calling as a subcommand    */
                          NULL,        /* no exits used              */
                          &rc,         /* converted return code      */
                          &retstr);    /* returned result            */