Black Box 4/BlackBox.cdr/os2/rexxapi.arj/REXXAPI.INF

OS/2 Help File | 1991-09-23 | 99.6 KB | 4,047 lines

ΓòÉΓòÉΓòÉ 1. 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 1.1. 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
   should be declared with the appropriate type definition from the REXXSAA.H
   include file: be compiled with the IBM C Set compiler options -Alfu:

    - RexxSubcomHandler
    - RexxFunctionHandler
    - RexxExitHandler

 o REXX handlers must be compiled with the IBM C Set compiler options -Alfu.

 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 called from any REXX program.

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


ΓòÉΓòÉΓòÉ 2. 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 may have a value (including the null string, "") or it may 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 zero. 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 may
     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. On calls to subcommand and external functions handlers, as well as some of
     the exit handlers, the REXX interpreter expects an RXSTRING value
     returned. The REXX 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 3. Invoking the REXX Interpreter ΓòÉΓòÉΓòÉ

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


ΓòÉΓòÉΓòÉ 3.1. From the OS/2 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 3.2. From Within an Application ΓòÉΓòÉΓòÉ

The REXX interpreter is a dynamic link library (DLL) routine. Any application
may 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 calling REXX is in the Developer's Toolkit REXXSAA.H
include file.


ΓòÉΓòÉΓòÉ 3.3. RexxStart ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

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


ΓòÉΓòÉΓòÉ <hidden> Call Syntax 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 ΓòÉΓòÉΓòÉ

RexxStart invokes the REXX interpreter to execute a REXX procedure.


ΓòÉΓòÉΓòÉ <hidden> Parameters 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 may 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 (2) 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 call to
    RexxStart 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 may be used in Instore[1] on subsequent RexxStart 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] may 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 may be 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 calling RexxStart 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 should not
    be moved to other systems or saved for later use. The tokenized image may,
    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
       may 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 may 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 may 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 RexxStart is responsible for releasing the
    RXSTRING storage with DosFreeMem.

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


ΓòÉΓòÉΓòÉ <hidden> Data Structures 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 ΓòÉΓòÉΓòÉ

RexxStart returns the following values:

 negative
    Interpreter errors.

 0
    No errors occurred.  The REXX procedure executed normally.

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


ΓòÉΓòÉΓòÉ <hidden> Notes ΓòÉΓòÉΓòÉ

The REXX interpreter is a dynamic link library (DLL) routine. Any application
may 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.


ΓòÉΓòÉΓòÉ <hidden> Related Functions ΓòÉΓòÉΓòÉ

The following functions are related to RexxStart:

 RexxAddMacro
 RexxRegisterSubcomExe
 RexxRegisterFunctionExe


ΓòÉΓòÉΓòÉ <hidden> Examples 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 4. 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 4.1. 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 4.2. Creating Subcommand Handlers ΓòÉΓòÉΓòÉ

The following example is a sample subcommand handler definition.


Sample Definition of a Subcommand Handler

ULONG RexxSubcomHandler 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 may 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 RexxSubcomHandler 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 5. 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 5.1. RexxRegisterSubcomDll ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

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


ΓòÉΓòÉΓòÉ <hidden> Call Syntax 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 ΓòÉΓòÉΓòÉ

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


ΓòÉΓòÉΓòÉ <hidden> Parameters 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 REXX will call as a
    subcommand handler.

 UserArea (PUCHAR) - input
    Address of an eight-byte area of user defined information. The eight-bytes
    addressed by UserArea will be saved with the subcommand handler
    registration. UserArea may 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 ΓòÉΓòÉΓòÉ

RexxRegisterSubcomDll returns the following values:

 0         RXSUBCOM_OK
 10        RXSUBCOM_DUP
 1002      RXSUBCOM_NOEMEM
 1003      RXSUBCOM_BADTYPE


ΓòÉΓòÉΓòÉ <hidden> Notes ΓòÉΓòÉΓòÉ

EntryPoint may 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 ΓòÉΓòÉΓòÉ

The following functions are related to RexxRegisterSubcomDll:

 RexxRegisterSubcomExe
 RexxDeregisterSubcom
 RexxQuerySubcom
 RexxStart


ΓòÉΓòÉΓòÉ 5.2. RexxRegisterSubcomExe ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

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


ΓòÉΓòÉΓòÉ <hidden> Call Syntax 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 ΓòÉΓòÉΓòÉ

RexxRegisterSubcomExe registers a subcommand handler that resides within
application code.


ΓòÉΓòÉΓòÉ <hidden> Parameters 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 eight-byte area of
    user defined information. The eight-bytes addressed by UserArea will be
    saved with the subcommand handler registration. UserArea may be NULL if
    there is no user information to save. The user information can be retrieved
    with the RexxQuerySubcom function.


ΓòÉΓòÉΓòÉ <hidden> Return Values ΓòÉΓòÉΓòÉ

RexxRegisterSubcomExe returns the following values:

 0         RXSUBCOM_OK
 10        RXSUBCOM_DUP
 30        RXSUBCOM_NOTREG
 1002      RXSUBCOM_NOEMEM
 1003      RXSUBCOM_BADTYPE


ΓòÉΓòÉΓòÉ <hidden> Notes 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 ΓòÉΓòÉΓòÉ

The following functions are related to RexxRegisterSubcomExe:

 RexxRegisterSubcomDll
 RexxDeregisterSubcom
 RexxQuerySubcom
 RexxStart


ΓòÉΓòÉΓòÉ <hidden> Examples 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 5.3. RexxDeregisterSubcom ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

 Call Syntax - RexxDeregisterSubcom
 Uses
 Parameters
 Return Values
 Errors
 Notes
 Related Functions


ΓòÉΓòÉΓòÉ <hidden> Call Syntax 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 ΓòÉΓòÉΓòÉ

RexxDeregisterSubcom deregisters a subcommand handler.


ΓòÉΓòÉΓòÉ <hidden> Parameters 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 ΓòÉΓòÉΓòÉ

RexxDeregisterSubcom returns the following values:

 0         RXSUBCOM_OK
 30        RXSUBCOM_NOTREG
 40        RXSUBCOM_NOCANDROP
 1003      RXSUBCOM_BADTYPE


ΓòÉΓòÉΓòÉ <hidden> Notes ΓòÉΓòÉΓòÉ

The handler is removed from the active subcommand handler list.


ΓòÉΓòÉΓòÉ <hidden> Related Functions ΓòÉΓòÉΓòÉ

The following functions are related to RexxDeregisterSubcom:

 RexxRegisterSubcomDll
 RexxRegisterSubcomExe
 RexxQuerySubcom


ΓòÉΓòÉΓòÉ 5.4. RexxQuerySubcom ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

 Call Syntax - RexxQuerySubcom
 Uses
 Parameters
 Return Values
 Errors
 Related Functions
 Examples


ΓòÉΓòÉΓòÉ <hidden> Call Syntax 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 ΓòÉΓòÉΓòÉ

RexxQuerySubcom queries a subcommand handler and retrieves saved user
information.


ΓòÉΓòÉΓòÉ <hidden> Parameters 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 eight-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 ΓòÉΓòÉΓòÉ

RexxQuerySubcom returns the following values:

 0         RXSUBCOM_OK
 30        RXSUBCOM_NOTREG
 1003      RXSUBCOM_BADTYPE


ΓòÉΓòÉΓòÉ <hidden> Related Functions ΓòÉΓòÉΓòÉ

The following functions are related to RexxQuerySubcom:

 RexxRegisterSubcomDll
 RexxRegisterSubcomExe
 RexxDeregisterSubcom


ΓòÉΓòÉΓòÉ <hidden> Examples ΓòÉΓòÉΓòÉ

The following examples show the use of RexxQuerySubcom:

ULONG RexxSubcomHandler 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> 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 6. 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 6.1. 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 6.2. Creating External Functions ΓòÉΓòÉΓòÉ

The following is a sample external function definition:


Sample External Function Definition

LONG RexxFunctionHandler 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 function name used to call the external
             function.

 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 with a function call,
             Retstr is used directly within the REXX expression.

             The REXX interpreter provides a default 256-byte RXSTRING in
             Retstr. A longer RXSTRING may 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 zero, the function completed successfully. Retstr
             contains the function return value. When the external function
             returns a non-zero, 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 should set Retstr to an an empty RXSTRING (NULL strptr).
             When an external function called as a function does not return a
             value, the interpreter raises error 44, "Function did not return
             data". When an external function called with the REXX CALL
             instruction does not return a value, the REXX interpreter drops
             (unassigns) the special variable RESULT.


ΓòÉΓòÉΓòÉ 6.3. Calling External Functions ΓòÉΓòÉΓòÉ

RexxRegisterFunctionExe Only REXX procedures running in the same process can
call 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 6.4. Sample External Function ΓòÉΓòÉΓòÉ

LONG RexxFunctionHandler 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 7. 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 7.1. RexxRegisterFunctionDll ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

 Call Syntax - RexxRegisterFunctionDll
 Uses
 Parameters
 Return Values
 Errors
 Notes
 Related Functions
 Examples


ΓòÉΓòÉΓòÉ <hidden> Call Syntax 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 ΓòÉΓòÉΓòÉ

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


ΓòÉΓòÉΓòÉ <hidden> Parameters 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 ΓòÉΓòÉΓòÉ

RexxRegisterFunctionDll returns the following values:

 0         RXFUNC_OK
 10        RXFUNC_DEFINED
 20        RXFUNC_NOMEM


ΓòÉΓòÉΓòÉ <hidden> Notes ΓòÉΓòÉΓòÉ

EntryPoint may 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 ΓòÉΓòÉΓòÉ

The following functions are related to RexxRegisterFunctionDll:

 RexxRegisterFunctionExe
 RexxDeregisterFunction
 RexxQueryFunction


ΓòÉΓòÉΓòÉ <hidden> Examples ΓòÉΓòÉΓòÉ

The following example shows the use of RexxRegisterFunctionDll:

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


LONG RexxFunctionHandler 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 7.2. RexxRegisterFunctionExe ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

 Call Syntax - RexxRegisterFunctionExe
 Uses
 Parameters
 Return Values
 Errors
 Related Functions


ΓòÉΓòÉΓòÉ <hidden> Call Syntax 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 ΓòÉΓòÉΓòÉ

RexxRegisterFunctionExe registers an external function that resides within
application code.


ΓòÉΓòÉΓòÉ <hidden> Parameters 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 issuer can call local external functions.


ΓòÉΓòÉΓòÉ <hidden> Return Values ΓòÉΓòÉΓòÉ

RexxRegisterFunctionExe returns the following values:

 0         RXFUNC_OK
 10        RXFUNC_DEFINED
 20        RXFUNC_NOMEM


ΓòÉΓòÉΓòÉ <hidden> Related Functions ΓòÉΓòÉΓòÉ

The following functions are related to RexxRegisterFunctionExe:

 RexxRegisterFunctionDll
 RexxDeregisterFunction
 RexxQueryFunction


ΓòÉΓòÉΓòÉ 7.3. RexxDeregisterFunction ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

 Call Syntax - RexxDeregisterFunction
 Uses
 Parameters
 Return Values
 Errors
 Related Functions


ΓòÉΓòÉΓòÉ <hidden> Call Syntax 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 ΓòÉΓòÉΓòÉ

RexxDeregisterFunction deregisters an external function.


ΓòÉΓòÉΓòÉ <hidden> Parameters ΓòÉΓòÉΓòÉ

RexxDeregisterFunction (FuncName)

Parameters:

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


ΓòÉΓòÉΓòÉ <hidden> Return Values ΓòÉΓòÉΓòÉ

RexxDeregisterFunction returns the following values:

 0         RXFUNC_OK
 30        RXFUNC_NOTREG


ΓòÉΓòÉΓòÉ <hidden> Related Functions ΓòÉΓòÉΓòÉ

The following functions are related to RexxDeregisterFunction:

 RexxRegisterFunctionDll
 RexxRegisterFunctionExe
 RexxQueryFunction


ΓòÉΓòÉΓòÉ 7.4. RexxQueryFunction ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

 Call Syntax - RexxQueryFunction
 Uses
 Parameters
 Return Values
 Errors
 Notes
 Related Functions


ΓòÉΓòÉΓòÉ <hidden> Call Syntax 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 ΓòÉΓòÉΓòÉ

RexxQueryFunction queries the existence of a registered external function.


ΓòÉΓòÉΓòÉ <hidden> Parameters ΓòÉΓòÉΓòÉ

RexxQueryFunction (FuncName)

Parameters:

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


ΓòÉΓòÉΓòÉ <hidden> Return Values ΓòÉΓòÉΓòÉ

RexxQueryFunction returns the following values:

 0         RXFUNC_OK
 30        RXFUNC_NOTREG


ΓòÉΓòÉΓòÉ <hidden> Notes 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 ΓòÉΓòÉΓòÉ

The following functions are related to RexxQueryFunction:

 RexxRegisterFunctionDll
 RexxRegisterFunctionExe
 RexxDeregisterFunction


ΓòÉΓòÉΓòÉ <hidden> Errors ΓòÉΓòÉΓòÉ

The following are the external function interface errors.:

 RXFUNC_OK
    The call to the function 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 8. 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 8.1. Writing System Exit Handlers ΓòÉΓòÉΓòÉ

The following is a sample exit handler definition:


Sample System Exit Handler Definition

LONG RexxExitHandler 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 call.

 Subfunction The subfunction code defining the exit event for the call.

 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 8.1.1. 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 had not been 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 8.1.2. 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 may contain null characters also.

For some exit subfunctions, the exit handler may 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 8.1.3. 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 named in sysexit_name
for all of the 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 RexxExitHandler 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 8.2. 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 8.3. RXFNC ΓòÉΓòÉΓòÉ

Process calls to external functions.

The RXFNC exit has the following subfunction:

 RXFNCCAL    Process calls to external functions.


ΓòÉΓòÉΓòÉ 8.3.1. RXFNCCAL ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics ΓòÉΓòÉΓòÉ

Process calls to external functions.

 When called: When REXX 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 calls to the RXFNC
 exit handler.


ΓòÉΓòÉΓòÉ <hidden> Parameters 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 call
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 call 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 8.4. RXCMD ΓòÉΓòÉΓòÉ

Process calls to subcommand handlers.

The RXCMD exit has the following subfunction:

 RXCMDHST    Call a named subcommand handler.


ΓòÉΓòÉΓòÉ 8.4.1. RXCMDHST ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics ΓòÉΓòÉΓòÉ

Call a named subcommand handler.

 When called: When a command is issued in a REXX procedure.

 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 calls to
 the RXCMD exit handlers.


ΓòÉΓòÉΓòÉ <hidden> Parameters 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 8.5. 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 8.5.1. RXMSQPLL ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics 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 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 8.5.2. RXMSQPSH ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics 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 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 8.5.3. RXMSQSIZ ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics 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 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 8.5.4. RXMSQNAM ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics 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 ΓòÉΓòÉΓòÉ

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

rxmsq_name contains the new queue name.


ΓòÉΓòÉΓòÉ 8.6. 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 8.6.1. RXSIOSAY ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics 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 ΓòÉΓòÉΓòÉ

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

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


ΓòÉΓòÉΓòÉ 8.6.2. RXSIOTRC ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics 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 ΓòÉΓòÉΓòÉ

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

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


ΓòÉΓòÉΓòÉ 8.6.3. RXSIOTRD ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics 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 ΓòÉΓòÉΓòÉ

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

The input stream line is returned in the rxsiotrd_retc RXSTRING.


ΓòÉΓòÉΓòÉ 8.6.4. RXSIODTR ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics 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 ΓòÉΓòÉΓòÉ

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

The input stream line is returned in the rxsiodtr_retc RXSTRING.


ΓòÉΓòÉΓòÉ 8.7. 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 may be
 used to halt a REXX program without between-instruction polling.


ΓòÉΓòÉΓòÉ 8.7.1. RXHLTTST ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics ΓòÉΓòÉΓòÉ

Test HALT indicator.

 When called: RXHLTTST is called by the interpreter to poll externally raised
 HALT conditions. The exit will be 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 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 8.7.2. RXHLTCLR ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics 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 ΓòÉΓòÉΓòÉ

(None)


ΓòÉΓòÉΓòÉ 8.8. 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 may be
 used to turn on REXX tracing without the between-instruction polling.


ΓòÉΓòÉΓòÉ 8.8.1. RXTRCTST ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics ΓòÉΓòÉΓòÉ

Test external trace indicator.

 When called: RXTRCTST is called by the interpreter to poll for an external
 trace event. The exit will be 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 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 8.9. RXINI ΓòÉΓòÉΓòÉ

Initialization processing.

The RXINT exit has the following subfunction:

 RXINIEXT    Initialization exit.


ΓòÉΓòÉΓòÉ 8.9.1. RXINIEXT ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics ΓòÉΓòÉΓòÉ

Initialization exit.

The RXINI exit is called as the last step of REXX program initialization. The
exit handler may 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 may 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 ΓòÉΓòÉΓòÉ

(None)


ΓòÉΓòÉΓòÉ 8.10. RXTER ΓòÉΓòÉΓòÉ

Termination processing.

The RXTER exit has the following subfunction:

 RXTEREXT    Termination exit


ΓòÉΓòÉΓòÉ 8.10.1. RXTEREXT ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Characteristics 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 may 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 ΓòÉΓòÉΓòÉ

(None)


ΓòÉΓòÉΓòÉ 9. 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 9.1. RexxRegisterExitDll ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

 Call Syntax - RexxRegisterExitDll
 Uses
 Parameters
 Return Values
 Errors
 Notes
 Related Functions


ΓòÉΓòÉΓòÉ <hidden> Call Syntax 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 ΓòÉΓòÉΓòÉ

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


ΓòÉΓòÉΓòÉ <hidden> Parameters 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 routine
    within ModuleName that REXX will call as an exit handler.

 UserArea (PUCHAR) - input
    Address of an eight-byte area of user defined information. The eight-bytes
    addressed by UserArea will be saved with the exit handler registration.
    UserArea may 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 ΓòÉΓòÉΓòÉ

RexxRegisterExitDll returns the following values:

 0         RXEXIT_OK
 10        RXEXIT_DUP
 1002      RXEXIT_NOEMEM
 1003      RXEXIT_BADTYPE


ΓòÉΓòÉΓòÉ <hidden> Notes ΓòÉΓòÉΓòÉ

EntryPoint may 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 ΓòÉΓòÉΓòÉ

The following functions are related to RexxRegisterExitDll:

 RexxRegisterExitExe
 RexxDeregisterExit
 RexxQueryExit


ΓòÉΓòÉΓòÉ 9.2. RexxRegisterExitExe ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

 Call Syntax - RexxRegisterExitExe
 Uses
 Parameters
 Return Values
 Errors
 Notes
 Related Functions
 Examples


ΓòÉΓòÉΓòÉ <hidden> Call Syntax 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 ΓòÉΓòÉΓòÉ

RexxRegisterExitExe registers an exit handler that resides within application
code.


ΓòÉΓòÉΓòÉ <hidden> Parameters 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 eight-byte area of user defined information. The eight-bytes
    addressed by UserArea will be saved with the exit handler registration.
    UserArea may be NULL if there is no user information to save. The user
    information can be retrieved with the RexxQueryExit function.


ΓòÉΓòÉΓòÉ <hidden> Return Values ΓòÉΓòÉΓòÉ

RexxRegisterExitExe returns the following values:

 0         RXEXIT_OK
 10        RXEXIT_DUP
 30        RXEXIT_NOTREG
 1002      RXEXIT_NOEMEM
 1003      RXEXIT_BADTYPE


ΓòÉΓòÉΓòÉ <hidden> Notes 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 ΓòÉΓòÉΓòÉ

The following functions are related to RexxRegisterExitExe:

 RexxRegisterExitDll
 RexxDeregisterExit
 RexxQueryExit


ΓòÉΓòÉΓòÉ <hidden> Examples 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 9.3. RexxDeregisterExit ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

 Call Syntax - RexxDeregisterExit
 Uses
 Parameters
 Return Values
 Errors
 Notes
 Related Functions


ΓòÉΓòÉΓòÉ <hidden> Call Syntax 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 ΓòÉΓòÉΓòÉ

RexxDeregisterExit deregisters an exit handler.


ΓòÉΓòÉΓòÉ <hidden> Parameters 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 ΓòÉΓòÉΓòÉ

RexxDeregisterExit returns the following values:

 0         RXEXIT_OK
 30        RXEXIT_NOTREG
 40        RXEXIT_NOCANDROP
 1003      RXEXIT_BADTYPE


ΓòÉΓòÉΓòÉ <hidden> Notes ΓòÉΓòÉΓòÉ

The handler is removed from the exit handler list.


ΓòÉΓòÉΓòÉ <hidden> Related Functions ΓòÉΓòÉΓòÉ

The following functions are related to RexxDeregisterExit:

 RexxRegisterExitDll
 RexxRegisterExitExe
 RexxQueryExit


ΓòÉΓòÉΓòÉ 9.4. RexxQueryExit ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

 Call Syntax - RexxQueryExit
 Uses
 Parameters
 Return Values
 Errors
 Related Functions
 Examples


ΓòÉΓòÉΓòÉ <hidden> Call Syntax 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 ΓòÉΓòÉΓòÉ

RexxQueryExit queries an exit handler and retrieves saved user information.


ΓòÉΓòÉΓòÉ <hidden> Parameters 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 eight-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 ΓòÉΓòÉΓòÉ

RexxQueryExit returns the following values:

 0         RXEXIT_OK
 30        RXEXIT_NOTREG
 1003      RXEXIT_BADTYPE


ΓòÉΓòÉΓòÉ <hidden> Related Functions ΓòÉΓòÉΓòÉ

The following functions are related to RexxQueryExit:

 RexxRegisterExitDll
 RexxRegisterExitExe
 RexxDeregisterExit


ΓòÉΓòÉΓòÉ <hidden> Examples ΓòÉΓòÉΓòÉ

The following example shows the use of RexxQueryExit:

ULONG RexxExitHandler 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> 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 10. Variable Pool Interface ΓòÉΓòÉΓòÉ

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


ΓòÉΓòÉΓòÉ 10.1. Interface Types ΓòÉΓòÉΓòÉ

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


ΓòÉΓòÉΓòÉ 10.1.1. 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 10.1.2. 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) may 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 10.2. RexxVariablePool Restrictions ΓòÉΓòÉΓòÉ

Only the main thread of an application can access the REXX variable pool.
Applications may create and use new threads, but only the original thread that
called RexxStart may 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 11. RexxVariablePool Interface Function ΓòÉΓòÉΓòÉ

REXX procedure variables are accessed using the RexxVariablePool function.


ΓòÉΓòÉΓòÉ 11.1. RexxVariablePool ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

 Call Syntax - RexxVariablePool
 Uses
 Parameters
 Data Structures
 Return Values
 Notes
 Examples


ΓòÉΓòÉΓòÉ <hidden> Call Syntax 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 ΓòÉΓòÉΓòÉ

RexxVariablePool accesses variables of a currently active REXX procedure.


ΓòÉΓòÉΓòÉ <hidden> Parameters 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 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 system exit call.
       RXSHV_EXIT is only valid from external functions or system exit events
       which return a string value. A single call is allowed per external call.

 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 at the time of the call.

    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 caller is responsible for
       releasing 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 caller is responsible for releasing
       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 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 when call was issued.


ΓòÉΓòÉΓòÉ <hidden> Notes ΓòÉΓòÉΓòÉ

The REXX interpreter processes each request block in the order provided;
RexxVariablePool returns to the caller after 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 ΓòÉΓòÉΓòÉ

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

INT SetRexxVariable(name, value)
  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 12. 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 system exits require an
additional call to an exit routine after each REXX instruction completes. This
may 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 13. 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 13.1. RexxSetHalt ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

 Call Syntax - RexxSetHalt
 Uses
 Parameters
 Return Values
 Notes


ΓòÉΓòÉΓòÉ <hidden> Call Syntax 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 ΓòÉΓòÉΓòÉ

RexxSetHalt raises a HALT condition in a running REXX program.


ΓòÉΓòÉΓòÉ <hidden> Parameters 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 ΓòÉΓòÉΓòÉ

RexxSetHalt returns the following values:

 0         RXARI_OK
 1         RXARI_PID_TID_NOT_FOUND
 2         RXARI_PROCESSING_ERROR


ΓòÉΓòÉΓòÉ <hidden> Notes ΓòÉΓòÉΓòÉ

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


ΓòÉΓòÉΓòÉ <hidden> Related Functions ΓòÉΓòÉΓòÉ

The following functions are related to RexxSetHalt:

 RexxSetTrace
 RexxResetTrace


ΓòÉΓòÉΓòÉ 13.2. RexxSetTrace ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

 Call Syntax - RexxSetTrace
 Uses
 Parameters
 Return Values
 Notes


ΓòÉΓòÉΓòÉ <hidden> Call Syntax 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 ΓòÉΓòÉΓòÉ

RexxSetTrace turns on interactive debug mode for a REXX procedure.


ΓòÉΓòÉΓòÉ <hidden> Parameters 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 ΓòÉΓòÉΓòÉ

RexxSetTrace returns the following values:

 0         RXARI_OK
 1         RXARI_PID_TID_NOT_FOUND
 2         RXARI_PROCESSING_ERROR


ΓòÉΓòÉΓòÉ <hidden> Notes ΓòÉΓòÉΓòÉ

A RexxSetTrace call will not be processed if the REXX procedure is using the
RXTRC exit.


ΓòÉΓòÉΓòÉ <hidden> Related Functions ΓòÉΓòÉΓòÉ

The following functions are related to RexxSetTrace:

 RexxSetHalt
 RexxResetTrace


ΓòÉΓòÉΓòÉ 13.3. RexxResetTrace ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

 Call Syntax - RexxResetTrace
 Uses
 Parameters
 Return Values
 Notes


ΓòÉΓòÉΓòÉ <hidden> Call Syntax 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 ΓòÉΓòÉΓòÉ

RexxResetTrace turns off interactive debug mode for a REXX procedure.


ΓòÉΓòÉΓòÉ <hidden> Parameters 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 ΓòÉΓòÉΓòÉ

RexxResetTrace returns the following values:

 0         RXARI_OK
 1         RXARI_PID_TID_NOT_FOUND
 2         RXARI_PROCESSING_ERROR


ΓòÉΓòÉΓòÉ <hidden> Notes ΓòÉΓòÉΓòÉ

A RexxResetTrace call will not be 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 ΓòÉΓòÉΓòÉ

The following functions are related to RexxResetTrace:

 RexxSetHalt
 RexxSetTrace


ΓòÉΓòÉΓòÉ 14. 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
may be executed using the RexxStart function or called as functions or
subroutines from other REXX procedures.

Procedures in the macrospace are called the same way other REXX external
functions are called. However, the macrospace REXX procedures may be placed at
the front or at the very 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 a single call to RexxLoadMacroSpace. An
application, such as an editor, can create its own library of frequently-used
functions and load the entire library into memory for fast access. Multiple
macrospace libraries may 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 may 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
 may 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 15. 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 15.1. RexxAddMacro ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

 Call Syntax - RexxAddMacro
 Uses
 Parameters
 Return Values
 Errors
 Related Functions
 Examples


ΓòÉΓòÉΓòÉ <hidden> Call Syntax 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 ΓòÉΓòÉΓòÉ

RexxAddMacro loads a REXX procedure into the macrospace.


ΓòÉΓòÉΓòÉ <hidden> Parameters ΓòÉΓòÉΓòÉ

RexxAddMacro (FuncName, SourceFile, Position)

Parameters:

 FuncName (PSZ) - input

    Address of the ASCIIZ function name. REXX procedures in the macrospace are
    called using the assigned function name.

 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 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 ΓòÉΓòÉΓòÉ

The following functions are related to RexxAddMacro:

 RexxDropMacro
 RexxClearMacroSpace
 RexxSaveMacroSpace
 RexxLoadMacroSpace
 RexxQueryMacro
 RexxReorderMacro


ΓòÉΓòÉΓòÉ 15.2. RexxDropMacro ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

 Call Syntax - RexxDropMacro
 Uses
 Parameters
 Return Values
 Errors
 Related Functions


ΓòÉΓòÉΓòÉ <hidden> Call Syntax 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 ΓòÉΓòÉΓòÉ

RexxDropMacro removes a REXX procedure from the macrospace.


ΓòÉΓòÉΓòÉ <hidden> Parameters ΓòÉΓòÉΓòÉ

RexxDropMacro (FuncName)

Parameters:

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


ΓòÉΓòÉΓòÉ <hidden> Return Values ΓòÉΓòÉΓòÉ

RexxDropMacro returns the following values:

 0         RXMACRO_OK
 2         RXMACRO_NOT_FOUND


ΓòÉΓòÉΓòÉ <hidden> Related Functions ΓòÉΓòÉΓòÉ

The following functions are related to RexxDropMacro:

 RexxAddMacro
 RexxClearMacroSpace
 RexxSaveMacroSpace
 RexxLoadMacroSpace
 RexxQueryMacro
 RexxReorderMacro


ΓòÉΓòÉΓòÉ 15.3. RexxClearMacroSpace ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

 Call Syntax - RexxClearMacroSpace
 Uses
 Parameters
 Return Values
 Errors
 Notes
 Related Functions


ΓòÉΓòÉΓòÉ <hidden> Call Syntax ΓòÉΓòÉΓòÉ

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

#define INCL_RXMACRO    /* Macrospace values */

ULONG   rc;         /* Return code        */

rc = RexxClearMacroSpace();


ΓòÉΓòÉΓòÉ <hidden> Uses ΓòÉΓòÉΓòÉ

RexxClearMacroSpace removes all loaded REXX procedures from the macrospace.


ΓòÉΓòÉΓòÉ <hidden> Parameters ΓòÉΓòÉΓòÉ

RexxClearMacroSpace ()

Parameters:

(None)


ΓòÉΓòÉΓòÉ <hidden> Return Values ΓòÉΓòÉΓòÉ

RexxClearMacroSpace returns the following values:

 0         RXMACRO_OK
 2         RXMACRO_NOT_FOUND


ΓòÉΓòÉΓòÉ <hidden> Notes ΓòÉΓòÉΓòÉ

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


ΓòÉΓòÉΓòÉ <hidden> Related Functions ΓòÉΓòÉΓòÉ

The following functions are related to RexxClearMacroSpace:

 RexxAddMacro
 RexxDropMacro
 RexxSaveMacroSpace
 RexxLoadMacroSpace
 RexxQueryMacro
 RexxReorderMacro


ΓòÉΓòÉΓòÉ 15.4. RexxSaveMacroSpace ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

 Call Syntax - RexxSaveMacroSpace
 Uses
 Parameters
 Return Values
 Errors
 Notes
 Related Functions
 Examples


ΓòÉΓòÉΓòÉ <hidden> Call Syntax 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 ΓòÉΓòÉΓòÉ

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


ΓòÉΓòÉΓòÉ <hidden> Parameters 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 ΓòÉΓòÉΓòÉ

RexxSaveMacroSpace returns the following values:

 0         RXMACRO_OK
 2         RXMACRO_NOT_FOUND
 3         RXMACRO_EXTENSION_REQUIRED
 5         RXMACRO_FILE_ERROR


ΓòÉΓòÉΓòÉ <hidden> Notes ΓòÉΓòÉΓòÉ

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

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


ΓòÉΓòÉΓòÉ <hidden> Related Functions ΓòÉΓòÉΓòÉ

The following functions are related to RexxSaveMacroSpace:

 RexxAddMacro
 RexxDropMacro
 RexxClearMacroSpace
 RexxLoadMacroSpace
 RexxQueryMacro
 RexxReorderMacro


ΓòÉΓòÉΓòÉ 15.5. RexxLoadMacroSpace ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

 Call Syntax - RexxLoadMacroSpace
 Uses
 Parameters
 Return Values
 Errors
 Notes
 Related Functions
 Examples


ΓòÉΓòÉΓòÉ <hidden> Call Syntax 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 ΓòÉΓòÉΓòÉ

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


ΓòÉΓòÉΓòÉ <hidden> Parameters 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 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 ΓòÉΓòÉΓòÉ

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

If a RexxLoadMacroSpace call would replace an existing macrospace REXX
procedure, the entire load request is discarded and the macrospace remains
unchanged.


ΓòÉΓòÉΓòÉ <hidden> Related Functions ΓòÉΓòÉΓòÉ

The following functions are related to RexxLoadMacroSpace:

 RexxAddMacro
 RexxDropMacro
 RexxClearMacroSpace
 RexxSaveMacroSpace
 RexxQueryMacro
 RexxReorderMacro


ΓòÉΓòÉΓòÉ 15.6. RexxQueryMacro ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

 Call Syntax - RexxQueryMacro
 Uses
 Parameters
 Return Values
 Errors
 Related Functions
 Examples


ΓòÉΓòÉΓòÉ <hidden> Call Syntax 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 ΓòÉΓòÉΓòÉ

RexxQueryMacro searches the macrospace for a specified function.


ΓòÉΓòÉΓòÉ <hidden> Parameters 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 ΓòÉΓòÉΓòÉ

RexxQueryMacro returns the following values:

 0         RXMACRO_OK
 2         RXMACRO_NOT_FOUND


ΓòÉΓòÉΓòÉ <hidden> Related Functions ΓòÉΓòÉΓòÉ

The following functions are related to RexxQueryMacro:

 RexxAddMacro
 RexxDropMacro
 RexxClearMacroSpace
 RexxSaveMacroSpace
 RexxLoadMacroSpace
 RexxReorderMacro


ΓòÉΓòÉΓòÉ 15.7. RexxReorderMacro ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ <hidden> Instructions ΓòÉΓòÉΓòÉ

Topics:

 Call Syntax - RexxReorderMacro
 Uses
 Parameters
 Return Values
 Errors
 Related Functions


ΓòÉΓòÉΓòÉ <hidden> Call Syntax 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 ΓòÉΓòÉΓòÉ

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


ΓòÉΓòÉΓòÉ <hidden> Parameters 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 ΓòÉΓòÉΓòÉ

RexxReorderMacro returns the following values:

 0         RXMACRO_OK
 2         RXMACRO_NOT_FOUND
 8         RXMACRO_INVALID_POSITION


ΓòÉΓòÉΓòÉ <hidden> Related Functions ΓòÉΓòÉΓòÉ

The following functions are related to RexxReorderMacro:

 RexxAddMacro
 RexxDropMacro
 RexxClearMacroSpace
 RexxSaveMacroSpace
 RexxLoadMacroSpace
 RexxQueryMacro


ΓòÉΓòÉΓòÉ <hidden> Errors ΓòÉΓòÉΓòÉ

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

 RXMACRO_OK
    The call to the function completed successfully

 RXMACRO_NO_STORAGE
    There was not enough memory to complete the requested function

 RXMACRO_NOT_FOUND
    The requested function 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 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            */