Handling Files on Application Server in SAP: DATASET Statement and other Tips

This article introduces working with files on application server in SAP with ABAP.

Its covers the most used functions to Handle Files on Application Server in SAP with ABAP with ready to run ABAP program to handle file.

Files on application server in sap with DATASET functions

OPEN DATASET

OPEN DATASET is for accessing files in a storage mode.
Filename should be the name of the file ( with path ) on application server.

OPEN DATASET Filename FOR access IN mode [position] 
                                         [os_addition] 
                                         [error_handling].

OPEN DATASET Access Mode

INPUT

FOR INPUT opens the file for reading.
if the file does not exist, the sy-subrc is set to 8.

OUTPUT

FOR OUPUT opens the file for writing.

If the file exists, the content will be deleted and remplaced
If the file does not exist, the file will be created.

APPENDING

FOR APPENDING open the file for appending.

The new content will be added to the end of existing file or the file will be created if not exist.
sy-subrc = 4 will be triggered if appending is not successfull.

UPDATE

FOR UPDATE opens the file for changes to the existing content.

Encoding

To handle file encoding, check this Abap Code Page

For the full documentation of OPEN DATASET, check this link

READ DATASET

The Standard ABAP Statement READ DATASET exports data from the file specified in dset into the data object dobj.

READ DATASET Filename INTO dobj [MAXIMUM LENGTH mlen] 
                                [[ACTUAL] LENGTH alen].

TRANSFER

ABAP Statement TRANSFER passes the content of data object dobj to the file specified in dset

TRANSFER dobj TO Filename [LENGTH len] 
                          [NO END OF LINE].

DELETE DATASET

DELETE DATASET deletes file on application service.
The file must open for output ( OPEN DATASET Filename FOR OUTPUT ) before deleting the file.

You CAN NOT delete the file unless you open the file for output.

DATA: lv_file(255).
OPEN DATASET  lv_file  FOR INPUT IN BINARY MODE.
IF sy-subrc EQ 0.
     CLOSE DATASET   lv_file.
     DELETE DATASET  lv_file.
     CLOSE DATASET   lv_file.
ENDIF.

More tools for handling Files on application server

File Functions

Read Application Server Directory in ABAP

In order to retrieve the list of all the directory in ABAP from Application server in ABAP, use the standard function module?RZL_READ_DIR.

An alternative to read application server Directory in ABAP is to use fm?EPS_GET_DIRECTORY_LISTING.

Application Server File with CL_RSAN_UT_APPSERV_*

CL_RSAN_UT_FILES

Utility Class for Supporting Files on GUI/App Server

CL_RSAN_UT_APPSERV_FILE_READER

Class Encapulating Block Reading from Application Server File

CL_RSAN_UT_APPSERV_FILE_WRITER

Class Encapulating Block Writing to App. Server File