The Retrieve  Field Data command  is a program  (TAADBLSR) that may  be
called  to retrieve  the data for  a field  in a  file.   An externally
described  data  structure (TAADBLSP)  and a  record  image is  used to
communicate with the  program.  The  intent of the tool  is to allow  a
general purpose  print program  where neither the  file nor  the fields
are  known when the  program is  written.  The  data to  be passed back
may include  editing characters  for decimal  data if  a  edit code  is
requested.

Assume you  want to  write a  general purpose  program to print  fields
from a  data base where the  name of the file and  fields are not known
when the program is written.

By using RTVFLDDTA, you can dynamically  access the data from a  record
image based on a field name.

The  companion  tool  is  RTVCOLHDG  which  will  retrieve  the  column
headings for a field.

The   TAADBLSP  externally  described   data  structure   provides  for
communication  to and from  the TAADBLSR program.   A record image must
also be passed.

The following parameters exist in the TAADBLSP data structure:

  **   FDRQST.   *CHAR LEN(8).   Input.   For normal  use pass  *FIELD.
       The program  remains open  to allow data  from another  field to
       be  retrieved.   When all data  has been  retrieved, pass *CLOSE
       which closes the program without retrieving any data.

  **   FDRTNC.  *CHAR LEN(8).   Input.  The return code from  TAADBLSR.
       Either *GOOD or *NOFLD is returned.

  **   FDFILE.  *CHAR LEN(10).   Input.  The file  name to retrieve the
       field from.

  **   FDLIB.   *CHAR  LEN(10).   Input.   The  library where  the file
       exists.

  **   FDFLD.   *CHAR LEN(10).   Input.   The  field  name to  retrieve
       data for.

  **   FDFLDT.   *CHAR LEN(1).   Input.   The  field type.   The  field
       type is  not used in RTVFLDDTA.  It  is determined from the file
       definition instead.

  **   FDDTAW.    *CHAR  LEN(5).   Input.    The  data  width including
       editing of  the field.   A maximum  of 44  is allowed.   If  the
       maximum is exceeded then 44 will be used.

  **   FDEDIT.   *CHAR LEN(1).  Input.   The edit  code associated with
       the  field.  '*'  should be  entered for character  fields or if
       you want  the  editing described  for the  field  in DDS.    '%'
       should  be entered  for 'no  editing'.   Packed  or binary  data
       will  be  converted.   Any of  the  standard edit  codes  may be
       entered.

  **   FDSTR.  *CHAR LEN(3).   Input.  The  field start location.   The
       field  start location  is not  used  in RTVFLDDTA.    It may  be
       input from  data gathered from RTVCOLHDG.   All data returned is
       left  justified in FDDATA  and FDPDTA.  The  intent of the field
       is to allow you  to store the important field information  in an
       array.

  **   FDDATA.   *CHAR LEN(256).  Output.   The first 256  bytes of the
       unedited  data.   Numeric  data is  positioned  in the  first 19
       bytes.

  **   FDPDTA.  *CHAR LEN(256).   Output.  The  first 256 bytes of  the
       edited data.   Numeric data is right-adjusted  and positioned in
       the field width.

  **   FDRSV.     *CHAR  LEN(100).    A   reserved  area  for  possible
       additional parameters.

The following code may be copied  to and RPG program to interface  with
the RTVFLDDTA program.   Your record image  should be moved to  the RCD
data structure left adjusted.

     IRCD         DS                           9999
     I              'TAATOOL/TAADBLSR'    C         GETDTA
     IFLDDTA    E DSTAADBLSP
     .
     C* It is generally preferable to have the following code in a
     C*  subroutine which allows it to be called with a request
     C*  value of *COLHDG or *CLOSE.
     C                     CALL GETDTA                     Get data
     C                     PARM           FLDDTA           Field data
     C                     PARM           RCD              Record data

RTVFLDDTA escape messages you can monitor for
---------------------------------------------

None.  Escape messages from based on functions will be re-sent.

CPF9898 is  sent for a variety  of error conditions such  as the FDFILE
or FDLIB parameters are blank.

RTVFLDDTA command parameters
----------------------------

No command exists.

Restrictions
------------

The maximum record width supported is 9999 bytes.

Prerequisites
-------------

The following TAA Tools must be on your system:

     RTVFLDARR       Retrieve field array
     SNDESCMSG       Send escape message

Implementation
--------------

None, the tool is ready to use.

Objects used by the tool
------------------------

   Object        Type    Attribute      Src member    Src file
   ------        ----    ---------      ----------    ----------

   TAADBLSR      *PGM       RPG         TAADBLSR      QATTRPG
   TAADBLSP      *FILE      PF          TAADBLSP      QATTDDS