There are two general kinds of double-byte character set (DBCS)
data: bracketed-DBCS data and graphic (nonbracketed) DBCS data.
Bracketed-DBCS data is preceded by a DBCS shift-out character and followed
by a DBCS shift-in character. Graphic-DBCS data is not surrounded by shift-out
and shift-in characters. The application program might require special processing
to handle bracketed-DBCS data that would not be required for graphic-DBCS
data.
The specific DBCS data types (specified in position 35 on the DDS coding
form.) are:
- Entry
- Meaning
- O
- DBCS-open: A character string that contains both single-byte and bracketed
double-byte data.
- E
- DBCS-either: A character string that contains either all single-byte data
or all bracketed double-byte data.
- J
- DBCS-only: A character string that contains only bracketed double-byte
data.
- G
- DBCS-graphic: A character string that contains only nonbracketed double-byte
data.
Note: Files containing DBCS data types can be created on a
single-byte character set (SBCS) system. Files containing DBCS data types
can be opened and used on a SBCS system, however, coded character set identifier
(CCSID) conversion errors can occur when the system tries to convert from
a DBCS or mixed CCSID to a SBCS CCSID. These errors do not occur
if the job CCSID is 65535.
DBCS constants
A constant identifies
the actual character string to be used. The character string is enclosed in
single quotation marks and a string of DBCS characters is surrounded by the
DBCS shift-out and shift-in characters (represented by the characters <
and > in the following examples). A DBCS-graphic constant is preceded by
the character G.
The types of DBCS constants are:
- Type
- Example
- DBCS-Only
- '<A1A2A3>'
- DBCS-Open
- '<A1A2A3>BCD'
- DBCS-Graphic
- G'<A1A2A3>'