ABAP to Upload files from SAP Application Server

*   Retrieve Data file from SAP Application server(Upload from Unix)
DATA: i_file like rlgrap-filename value '/usr/sap/tmp/file.txt'.

    OPEN DATASET i_file FOR INPUT IN TEXT MODE.
    IF sy-subrc NE 0.
      MESSAGE e999(za) WITH 'Error opening file' i_file.
    ENDIF.
    DO.
*     Reads each line of file individually
      READ DATASET i_file INTO wa_datatab.
*     Perform processing here
*     .....
    ENDDO.