SAP NEWS-610-DATASET documentation, setup help and example usage

File Interface in Release 6.10

The file interface in Release 6.10 has been completely overhauled. The changes and developments affect the following topics:

1 Adapting to Unicode
2 Reading and changing file properties at runtime
3 New classes for converting files
4 Support for files larger than 2 gigabytes
5 Limiting data range when reading files


ABAP_MODIFICATION_1 Adapting to Unicode

Extensive changes to the file interface have been made as a result of conversion to Unicode . For more information, see the
file interface in Unicode programs.

ABAP_MODIFICATION_2 Reading and changing file properties at runtime

The GET DATASET ... statement returns both the current read or write positions and the file properties. In turn, you can set a desired file position at runtime using the SET DATASET ... statement. You can also change the properties of the file, but the system only copies values compatible with the opening mode (such as FOR INPUT or FOR OUTPUT ).


ABAP_MODIFICATION_3 New classes for converting files

The following three classes were introduced for converting files:
CL_ABAP_CONV_IN_CE : Instances of this class enable the conversion of external binary data to valid ABAP data objects
CL_ABAP_CONV_OUT_CE : Instances of this class convert ABAP data objects to binary data.
CL_ABAP_CONV_X2X_CE : Instances of this class allow you to convert the text data of various character sets and the numeric data of various number formats.


ABAP_MODIFICATION_4 Support for files larger than 2 gigabytes

Files larger than 2 gigabytes can now be read and written on all platforms that support large files. Only the platforms OS/390 and
IBM System i (previously AS/400 ) are currently not included in this change. Additionally, the
OPEN DATASET statement has been enhanced in such a way that, when opening a file, the file pointer also addresses positions larger than 2 gigabytes.


ABAP_MODIFICATION_5 Limiting data range when reading files

The amount of files to be read can be limited using the addition MAXIMUM LENGTH maxlen . Depending on the mode in which the file was opened, maxlen defines the maximum number of characters or bytes, which are to be read from the file.