This document describes the installation steps for enabling the use of
                      the Natural statements REQUEST DOCUMENT and PARSE XML
                      on z/OS.
               
For information on the functions provided by REQUEST
                         DOCUMENT and PARSE XML, see the following documents:
               
Statements for Internet and XML Access in the Programming Guide
REQUEST
                                    DOCUMENT in the Statements
                              documentation
                     
PARSE XML in
                              the Statements documentation
                     
The following requirements must be met to execute the REQUEST
                          DOCUMENT and PARSE XML statements: 
               
The ICU library must be installed to convert data from one encoding to another (at least internally). For details, see the relevant section in the Unicode and Code Page Support documentation.
A TCP/IP stack must be available and enabled for the execution environment.
A DNS (Domain Name System) server or DNS services must be available in
                               the execution environment to resolve internet addresses
                               (gethostbyname function).
                     
For Internet Protocol Version 6 (IPv6) support, the following additional prerequisites apply:
An activated IPv6 stack must be available on the local host.
The local network must support IPv6.
An accessible and IPv6-capable DNS server must be available.
For IPv6 internet communication, an IPv6 connection from the service provider must be available.
If both IPv4 and IPv6 are used, a dual stack must be supported.
IPv6 support must be configured with the appropriate keyword
                               subparameters of the Natural profile parameter
                               XML
                               described in the Parameter Reference documentation.
                     
See also General Prerequisites and System Support in the section Overview of the Installation Process.
Be sure to read Installation Process and Major Natural Features before you start the installation procedure.
The installation procedure comprises the following:
The module NATXML is required to execute
                        the statements REQUEST DOCUMENT and PARSE XML. If you want the PARSE XML statement to support IBM
                        architecture level 9, alternatively, you can use the module
                        NATXMLA9. See also Support for Architecture
                           Levels.
               
 Set the System
                                   Maintenance Aid (SMA) parameter NATXML to
                                Y (default is N).
                     
The NATXML module is then linked to the
                                environment-independent
                                   nucleus by using the following INCLUDE statement:
                     
INCLUDE NATLIB(NATXML)
Or:
For support of IBM architecture level 9:
 Set the SMA
                                 parameters NATXML and
                                 NAT-ARCHLEVEL9 to Y (default is
                                 N). 
                     
The alternative NATXMLA9 module is then linked to the
                                 environment-independent
                                    nucleus by using the following INCLUDE statement:
                     
INCLUDE NATLIB(NATXMLA9)
The REQUEST DOCUMENT and PARSE XML statements
                        require the IBM Language Environment (LE) for
                        execution. If you want Natural to run in the IBM Language
                        Environment (LE), perform the following steps:
               
 Set the System
                                   Maintenance Aid (SMA) parameter NAT-LE  to
                                Y (Yes). The default setting is N (No).
                     
Additionally, if you want to modify the LE options in the
                                NATLEOPT source module or if you use non-Natural programs running
                                in 24-bit mode, set the appropriate SMA parameter as described in
                                Build the Natural-Specific IBM
                                   Language Environment Options in Installing
                                   Natural. 
                     
Link the environment-dependent nucleus to support LE.
This applies to all batch and TP monitor system environments except Com-plete and CICS.
Link the modules indicated in this section to the nucleus depending on the environment to be used.
In the following instructions,
                         hilev denotes a valid high-level
                         qualifier. 
               
Add the LE library (usually
                                 hilev.SCEELKED) to the
                                 SYSLIB definition of the link step to resolve the references to LE
                                 functions.
                     
Link the LE and TCP/IP access modules to the
                                 environment-dependent
                                    nucleus by using the appropriate INCLUDE
                                 statements:
                     
INCLUDE NATLIB(NAT2LE) INCLUDE NATOLIB(NAT2TCP)
Do not specify the NCAL parameter
                                 for the link step.
                     
Add the LE library (usually
                                 hilev.SCEELKED) to the
                                 SYSLIB definition of the link step to resolve the references to LE
                                 functions.
                     
Add the CICS socket library (usually
                                 hilev.SEZARNT1,
                                 hilev.SEZATCP or
                                 hilev.SEZACMTX) to the
                                 SYSLIB definition of the link step to resolve the reference to the
                                 CICS socket module.
                     
Link the CICS socket module to the
                                 environment-dependent
                                    nucleus by using the appropriate INCLUDE statement:
                     
INCLUDE NATLIB(NAT2LE) INCLUDE NCIOLIB(NCI2TCP) INCLUDE CICSSOCK(EZACIC17)
Do not specify the NCAL parameter
                                 for the link step.
                     
Configure the CICS TCP/IP environment as described in the IP CICS Socket Guide by IBM.
Link the LE access module to the
                                 environment-dependent
                                    nucleus by using the appropriate INCLUDE statement:
                     
INCLUDE NATLIB(NAT2LE)
Copy the NCFTCPvr module
                                 from the Natural Com-plete Interface load library to the Com-plete load
                                 library. 
                     
For support of the IBM TCP/IP stack, define the CDI (Communication Driver Interface) as described in Standard CDI Definitions in the Com-plete documentation.
Add the POSIX SERVER statement to the Com-plete
                                 parameter module SYSPARM.
                     
Add the LE library (usually
                                 hilev.SCEELKED) to the
                                 SYSLIB definition of the link job to resolve the references to LE
                                 functions.
                     
Link the LE and TCP/IP access modules to the
                                 environment-dependent
                                    nucleus by using the appropriate INCLUDE
                                 statements:
                     
INCLUDE NATLIB(NAT2LE) INCLUDE NATOLIB(NAT2TCP)
Do not specify the NCAL parameter
                                 for the link step.
                     
If your Natural system runs on z/OS or z/VSE with an IBM processor with
                       architecture level 9 or higher, you can replace the module NATXML
                       by NATXMLA9. NATXMLA9 is built to use advanced
                       machine instructions introduced with IBM’s ESA/390 and z/Architecture. You can
                       use the system command TECH (see the
                       System Commands documentation) to find out the
                       architecture level supported on your current machine.
               
NATXMLA9 improves execution performance, especially for the
                       statements REQUEST DOCUMENT and PARSE XML that use
                       Unicode variables or perform code-page encoding operations. For more
                       information on architecture levels, refer to the related documentation from IBM
                       (z/Architecture, Principles of Operation).
               
| Warning: An operation exception error (abend code S0C1) can occur if the NATXMLA9 module is used, but the underlying machine architecture
                                   level is lower than 9. | 
                     
After the last step of the installation procedure has been completed, proceed as follows:
Activate the statements in the runtime environment; see Activation/Deactivation in the section Statements for Internet and XML Access in the Programming Guide.
For information on the profile settings that enable the support of the
                               REQUEST DOCUMENT
                               and/or PARSE XML
                               statement, see the following documents:
                     
Profile Settings in the section Statements for Internet and XML Access in the Programming Guide
Profile parameter XML in the
                                       Parameter Reference documentation
                           
Try the example programs contained in the Natural system library
                               SYSEXV.