Reading fixed length flatfile & splitting it into header and lineitem data

Question

Hi Friends,
I am reading a fixed length flat file from application server into an Internal table.
But problem is, data in flat file is in the below format with fixed start and end positions.
1 - 78 -  control header
1 - 581 - Invoice header data
1 - 411 - Invoice Line item data
1 - 45 -   trailer record
There will be one control header and one trailer record per file and number of invoice headers and its line items can vary.
There is unique identifiers to identify as below.
Control header - starts with 'CHR'
Invoice Header starts with - '000'
Invoice Lineitem stats with - '001'
trailer record - starts with 'TRL'
So its like
CHR.......control  data..(79)000.....header data...(660)001....lineitem1...(1481)001...lineitem2....multiples of 411 and 581 and ends with... TRL...trailer record..
(position)
I am first reading the data set and store in internal table with a field of 255char.
by looping on above ITAB i have to split it into Header records and line item records.
Did anyone face this kind of scenario before. If yes appreciate if you can throw some ideas on logic to split this data.
Any help in splitting up the data is highly appreciated.
Regards,
Simha
ITAB declaration
DATA: BEGIN OF ITAB OCCURS 0,
               FIELD(255),
           END OF ITAB,
            lt_header type table of ZTHDR,
            lt_lineitem type table of ZTLINITM.

Answer 1

Hi,
i am sending sample code which resembles your requiremeant.
data: BEGIN OF it_input OCCURS 0, "used for store all the data in one line.
      line type string ,
      END OF it_input,
      it_header type TABLE OF string WITH HEADER LINE,"use to store all header with corresponding items
      it_item   type TABLE OF string WITH HEADER LINE.."used to store all item data
CALL FUNCTION 'GUI_UPLOAD'
  EXPORTING
    filename                      = 'd:\test.txt'
  FILETYPE                      = 'ASC'
  HAS_FIELD_SEPARATOR           = ' '
  HEADER_LENGTH                 = 0
  READ_BY_LINE                  = 'X'
  DAT_MODE                      = ' '
  CODEPAGE                      = ' '
  IGNORE_CERR                   = ABAP_TRUE
  REPLACEMENT                   = '#'
  CHECK_BOM                     = ' '
  VIRUS_SCAN_PROFILE            =
  NO_AUTH_CHECK                 = ' '
IMPORTING
  FILELENGTH                    =
  HEADER                        =
  tables
    data_tab                      = it_input
EXCEPTIONS
  FILE_OPEN_ERROR               = 1
  FILE_READ_ERROR               = 2
  NO_BATCH                      = 3
  GUI_REFUSE_FILETRANSFER       = 4
  INVALID_TYPE                  = 5
  NO_AUTHORITY                  = 6
  UNKNOWN_ERROR                 = 7
  BAD_DATA_FORMAT               = 8
  HEADER_NOT_ALLOWED            = 9
  SEPARATOR_NOT_ALLOWED         = 10
  HEADER_TOO_LONG               = 11
  UNKNOWN_DP_ERROR              = 12
  ACCESS_DENIED                 = 13
  DP_OUT_OF_MEMORY              = 14
  DISK_FULL                     = 15
  DP_TIMEOUT                    = 16
  OTHERS                        = 17
IF sy-subrc <> 0.
MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
        WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
ENDIF.
LOOP AT  it_input.
   write : it_input-line.
ENDLOOP.
before doing the below steps just takethe controle record and trail record cutt of from the table input based up on the length
  split it_input-line AT '000' INTO TABLE it_header IN CHARACTER MODE.
  LOOP AT  it_header.
    split it_header AT '0001' INTO TABLE it_item IN CHARACTER MODE.
    write :/ it_header.
  ENDLOOP.
after this you need to cut the records in tocorresponding  fields in to respective tables by putting loop on item and header table as i decleared above.
i think this may solve your problem you need to keep some minnor effort.
Regaurds,
Sree..