SYSEXT Utility - Natural Application Programming Interfaces

The utility SYSEXT is used to locate and test Natural Application Programming Interfaces (APIs) contained in the current system library SYSEXT.

A Natural API is a Natural subprogram (cataloged object) that is used for accessing and possibly modifying data or performing services that are not accessible by Natural statements. Natural APIs refer to Natural, a subcomponent or a subproduct.

The SYSEXT Utility - Natural Application Programming Interfaces documentation covers the following topics:

Related Topics:


Introduction to SYSEXT

For each Natural API, the utility SYSEXT provides a functional description, one example program, one category and API-specific keywords.

The following diagram is an overview of the Natural objects and major features SYSEXT provides:

graphics/sysext.png

Objects Provided for Natural APIs

The types of Natural object typically provided for each Natural API are listed in the following section. Additional objects that might exist for a particular API are not covered.

All API-related objects are contained in the library SYSEXT on the system file FNAT.

In the following table, nnnn denotes the 4-digit number to identify the API as well as the corresponding example program and text object.

Object Name Explanation
USRnnnnN The API subprogram (cataloged object) that performs the designated function.
USRnnnnP

An example program (source object) that can be used to test the effect of the API.

The example program invokes the corresponding subprogram USRnnnnN.

USRnnnnT

A text object listing a short and a long description, and information on usage, keywords, category and interface versions.

You can display a text object by using the line command T as described in Line Commands.

For some APIs, copycodes are available which provide functions related to the API. The copycodes are named USRnnnnX, where X is an identification character (such as "Z", "Y" etc.).

Invoking and Terminating SYSEXT

The SYSEXT utility is invoked by the system command SYSEXT which is described by the following syntax diagram:

SYSEXT

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ALL

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FIRST

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DESCENDING

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CURRENT SECOND ASCENDING

The table below gives a description of the parameters:

Parameter Description
ALL List all APIs (default).
CURRENT List only current APIs, that is all unique APIs and the current version of APIs with interface versions (with keyword +CURRENT-VERSION). See Interface Versions.
FIRST Display first menu with product code items (default), see below for an example.
SECOND Display second menu with category items, see below for an example.
ASCENDING Display APIs in ascending order (default).
DESCENDING Display APIs in descending order.

Start of instruction set To invoke SYSEXT

  • Enter the following system command:

    SYSEXT

    A menu similar to the example below appears with a list of all available Natural APIs displayed according to the first menu:

     07:43:19              ***** NATURAL SYSEXT UTILITY *****             2010-09-15
     User SAG                            - Menu -                   Library SYSEXT
    
     Cmd Interface Description                                                  Prod
     --- USR*____  _____________________________________________________________ *__
      _  USR0010N  Get SYSPROF information                                       NAT
      _  USR0011N  Get information on logical file                               NAT
      _  USR0020N  Read any error message from FNAT or FUSER                     NAT
      _  USR0040N  Get type of last error                                        NAT
      _  USR0050N  Get SYSPROD information                                       NAT
      _  USR0060N  Copy LFILE definition from FNAT to FUSER                      NAT
      _  USR0070P  Define editor default profile 'SYSTEM'                        NAT
      _  USR0080N  Get or set type and name of editor contents                   NAT
      _  USR0100N  Maintain record length of VSAM datasets                       NVS
      _  USR0120N  Read Natural short error message                              NAT
      _  USR0210N  Save, catalog or stow Natural object                          NAT
      _  USR0220N  Read Natural long error message                               NAT
      _  USR0320N  Read user short error message from FNAT or FUSER              NAT
    
      Category .. ______________________________  Keyword .. ____________________
    
     Command ===>
     Enter-PF1---PF2---PF3---PF4---PF5---PF6---PF7---PF8---PF9---PF10--PF11--PF12---
           Help  Reset Exit  Desc  Curr  --    -     +     ++          >     Canc   

You can invoke SYSEXT with any parameters, for example to display the second menu at startup:

SYSEXT SECOND

This results in a menu similar to the one below:

 07:43:19              ***** NATURAL SYSEXT UTILITY *****             2010-09-15
 User SAG                            - Menu -                   Library SYSEXT

 Cmd Interface Description                        Category
 --- USR*____  __________________________________ *_____________________________
  _  USR0010N  Get SYSPROF information            SYSTEM COMMANDS
  _  USR0011N  Get information on logical file    SYSTEM FILES
  _  USR0020N  Read any error message from FNAT o ERROR MESSAGES
  _  USR0040N  Get type of last error             ERROR HANDLING
  _  USR0050N  Get SYSPROD information            SYSTEM COMMANDS
  _  USR0060N  Copy LFILE definition from FNAT to SYSTEM FILES
  _  USR0070P  Define editor default profile 'SYS EDITOR
  _  USR0080N  Get or set type and name of editor EDITOR
  _  USR0100N  Maintain record length of VSAM dat VSAM
  _  USR0120N  Read Natural short error message   ERROR MESSAGES
  _  USR0210N  Save, catalog or stow Natural obje NATURAL OBJECTS
  _  USR0220N  Read Natural long error message    ERROR MESSAGES
  _  USR0320N  Read user short error message from ERROR MESSAGES

  Category .. ______________________________  Keyword .. ____________________

 Command ===>
 Enter-PF1---PF2---PF3---PF4---PF5---PF6---PF7---PF8---PF9---PF10--PF11--PF12---
       Help  Reset Exit  Desc  Curr  --    -     +     ++    <           Canc   

As an alternative, you can invoke SYSEXT without parameters and then adjust the resulting menu, see PF Keys.

Start of instruction set To terminate SYSEXT

  • On the SYSEXT utility menu, press PF3 or PF12.

    Or:
    In the command line, enter a period (.) or enter EXIT.

Using the SYSEXT Utility

This section covers the following topics:

Elements of the SYSEXT Utility Menu

The SYSEXT utility menu provides a list of APIs. For each API, there is an API name (Interface), a description (Description), and, depending on the menu chosen, a classification according to product code (Prod) or category (Category). Except for the leftmost column (Cmd), each column is headed by a selection field that allows you to enter selection criteria.

You can also use the search field Category at the bottom of the menu to search for available categories.

The input field Keywords can either be used as search field to retrieve available keywords, or as selection field to retrieve APIs.

You can also specify selection criteria on multiple selection fields. For example, you can select in one step APIs beginning with USR4, and with keyword PF-KEY and category NATURAL ENVIRONMENT.

A detailed description of all menu elements and their usage is given below:

Element Explanation Usage
Cmd The input field for a line command to be executed on a text object or an example program: see Line Commands. Enter a line command, example:
K List all keywords relevant to the specified API.
Interface The name of the API subprogram. APIs with interface versions are displayed intensified. Enter an asterisk (*) , or a prefix to be delimited by an asterisk, example:
USR4* List all APIs with prefix USR4.
Description A brief description of the purpose of the API. Enter a string, example:
default List all APIs with a description containing the string default or Default.
* List all APIs with a description that contains the string *.
Prod

The product code of Natural (NAT) or a Natural add-on product affected by the API.

Available product codes: NAT = Natural, NCI = Natural for CICS, NDB = Natural for DB2, NVS = Natural for VSAM, , NDV = Natural Development Server, PRD = Predict, RPC = Natural RPC (Remote Procedure Call).

Product codes other than NAT are displayed intensified.

Only visible on the first menu.

Enter a name, or a prefix to be delimited by an asterisk (*), example:
N* List all APIs with a product code beginning with N.
Category (selection field)

The category by which the API is classified according to its functional area or purpose.

An API can only have one category.

Only visible on the second menu and positioned above the list of APIs.

Enter a name, or a prefix to be delimited by an asterisk (*), example:
NATURAL OBJECTS List all APIs with category NATURAL OBJECTS.
Category (search field )

List all categories.

Positioned below the list of APIs.

See Category Search.
Keyword List all keywords or enter a keyword as selection criterion. See Keyword Search or Keyword Selection.
Command Command line to enter utility commands. Enter a utility command. See Utility Commands.

Start of instruction setCategory Search

  • Enter an asterisk (*), or a prefix in the category search field optionally delimited by an asterisk, for example:

    N*

    As a result, a menu similar to the example below appears:

             Search for Categories
    
      Mark Category
      ---- N*____________________________
        _  NATURAL ENVIRONMENT
        _  NATURAL OBJECTS

    To select a specific category as selection criterion, enter any character in the Mark column. As a result, a list of all APIs with this selection criterion is displayed.

Start of instruction setKeyword Search

  • Enter an asterisk (*), or a prefix delimited by an asterisk, for example:

    PF*

    A menu similar to the example below appears with a separate window displaying keywords starting with PF.

             Search for Keywords
    
      Mark Keyword
      ---- PF*_________________
        _  PF-KEY
        _  PF-KEY LINE

    To select a specific keyword as selection criterion, enter any character in the Mark column. As a result, a list of all APIs with this selection criterion is displayed.

Start of instruction setKeyword Selection

  • Enter a keyword in full, for example:

    PF-KEY

    As a result, a list of all APIs with keyword PF-KEY is displayed.

    Note:
    A non-trailing asterisk is interpreted literally, for example entering *LANGUAGE results in a list of APIs with keyword *LANGUAGE.

PF Keys

You can use the following PF keys:

PF Key Name Function
PF1 Help Display context-sensitive help. There is a specific help text for each input field. In other contexts, for example the command line, a general help text is displayed.
PF2 Reset Clear all selection fields and readjust the list of APIs.
PF3 Exit Exit the SYSEXT utility, or the current menu or window.
PF4 Asc/Desc Toggle between ascending (Asc) and descending (Desc) order of APIs.
PF5 All/Curr Toggle between menus displaying all APIs (All) and menus displaying only current APIs (Curr). See Interface Versions.
PF6 -- Scroll to the beginning of the list.
PF7 - Scroll one page up.
PF8 + Scroll one page down.
PF9 ++ Scroll to the end of the list.
PF10 < Shift to first menu.
PF11 > Shift to second menu.
PF12 Canc Exit the SYSEXT utility or the current menu or window.

Line Commands

Line commands are used to perform object operations. You can enter a line command in the Cmd column next to the API required. For a list of valid line commands, enter a question mark (?) or press PF1.

The following line commands are available:

Line Command Function
K List keywords relevant to the specified API.
T List text object USRnnnnT for a description of the corresponding API.

The description comprises purpose, function and calling conventions of the API, relevant keywords and its category.

L List example program USRnnnnP.
E Edit example program USRnnnnP.
R Run example program USRnnnnP.
X Execute example program USRnnnnP.
. Exit the SYSEXT utility.

Utility Commands

This section covers the following utility commands to be entered in the command line:

  • EXIT
    Exit the SYSEXT utility.

  • REFRESH
    Update API information using data from the objects contained in the current library SYSEXT. The REFRESH command is only required if an API description or a keyword has been modified or if a text object has been added or removed.

    Upon successful completion, there is a confirmation that the text modules EXT-XML1 and EXT-XML2 have been generated in library SYSEXT.

    Note:
    Do not modify the source objects EXT-XML1 and EXT-XML2. They are required for configuring the SYSEXT utility and intended for Software AG internal use only.

Interface Versions

Interface versions can be seen as a collection of APIs with (almost) the same functionality but with differently extended parameter specifications. Thus, they cover a development cycle to be kept explicit for sake of compatibility (of later versions with earlier versions).

If an API has interface versions, they are displayed in the corresponding text object USRnnnnT. Interface versions are ordered within a list according to the version they belong to. The rightmost element belongs to the current version. This status is expressed by the reserved keyword +CURRENT-VERSION. All other elements belong to a previous version and are marked with the reserved keyword +PREVIOUS-VERSION. APIs without interface versions are called unique.

APIs with interface versions are displayed intensified on the menu.

The list of all current APIs (see PF5) consists of all unique APIs and the current version of APIs with interface versions (with keyword +CURRENT-VERSION).

Reserved Keywords

Reserved keywords refer to meta information on APIs, for example the Natural version in which an API has been added. Reserved keywords always start with a plus sign (+). See the table below for a description:

Reserved Keyword Description
+CURRENT-VERSION The current version of an API with interface versions (see Interface Versions).
+PREVIOUS-VERSION A previous version of an API with interface versions (see Interface Versions).
+NEW-PROD-version An API that has been added to a specific product in a specific version. For example, +NEW-NAT-4.2.7 refers to an API that has been added to the product Natural in version 4.2.7.
+MOD-PROD-version An API that belongs to a specific product and has been modified in a specific version. For example, +MOD-NAT-8.2.1 refers to an API that belongs to product Natural and has been modified in version 8.2.1.

Using a Natural API

If you want to use a Natural API contained in the system library SYSEXT, perform one of the following steps:

  • Define the system library SYSEXT in the system file FNAT as a steplib library for the user library that contains the Natural objects that use this API. Thus, no API-specific actions are required when upgrading your Natural version.

  • Copy the required API to the system library SYSTEM in the system file FNAT. Thus, you only need to check a single library for APIs when upgrading your Natural version.

  • Copy the required API to the system library SYSTEM in the system file FUSER (not recommended).

  • Copy the required API to the user library (or one of its steplibs) in the system file FUSER which contains the Natural objects that use this API (not recommended).

An API can only be used in the Natural version with which it is delivered. It is strongly recommended to store the APIs only in the FNAT system file. This will ensure that the right version is always executed.

Start of instruction setTo make use of an interface

  1. In the calling program, use the DEFINE DATA statement to specify the parameters listed in the text object USRnnnnT of that API. In the example program USRnnnnP, the parameters are defined within the DEFINE DATA LOCAL statement. Alternatively, you can specify the parameters outside the calling program in a separate LDA (Local Data Area) or PDA (Parameter Data Area), with a DEFINE DATA LOCAL USING statement referencing that data area.

  2. Enter the following statement:

    CALLNAT 'USRnnnnN' parameters

    For further information, see the CALLNAT statement in the Statements documentation.

Note:
Non-standard usage is always documented in the respective text object USRnnnnT.

If you want to use a Natural copycode contained in the system library SYSEXT, perform the following step:

  • Copy the required copycode to the user library in the system file FUSER which contains the Natural objects that use this copycode.

Start of instruction setTo make use of a copycode

  1. In the calling program, use the INCLUDE statement to specify the parameters listed in the text object USRnnnnT of that API or in the copycode itself. In the example program USRnnnnP, the parameters are defined within the DEFINE DATA LOCAL statement. Alternatively, you can specify the parameters outside the calling program in a separate LDA (Local Data Area) or PDA (Parameter Data Area), with a DEFINE DATA LOCAL USING statement referencing that data area.

  2. Some copycodes require additional data definitions. These are described in the text object USRnnnnT of the API and in the copycode itself.

  3. Enter the following statement:

    INCLUDE USRnnnnX 'parameter'...

    For further information, see the INCLUDE statement in the Statements documentation.

Note:
Non-standard usage is always documented in the respective text object USRnnnnT.