File Management - IBM

Invalid double-byte code and undefined double-byte code
202 File Management V4R5
Invalid double-byte code has a double-byte code value that is not in the valid
double-byte code range. Figure 18 on page 199 shows valid double-byte code
ranges. This is in contrast to undefined double-byte code where the double-byte
code is valid, but no graphic symbol has been defined for the code.
Using double-byte data
This section tells you where you can use double-byte data and discusses the
limitations to its use.
Where you can use double-byte data
You can use double-byte data in the following ways:
v As data in files:
– Data in database files.
– Data entered in input-capable and data displayed in output-capable fields of
display files.
– Data printed in output-capable fields in printer files.
– Data used as literals in display files and printer files.
v As the text of messages.
v As the text of object descriptions.
v As literals and constants, and as data to be processed by high-level language
programs.
Double-byte data can be displayed only at DBCS display stations and printed only
on DBCS printers. Double-byte data can be written onto diskette, tape, disk, and
optical storage.
Where you cannot use double-byte data
You cannot use double-byte data in the following ways:
v As AS/400 object names.
v As command names or variable names in control language (CL) and other
high-level languages.
v As displayed or printed output on alphanumeric work stations.
Double-byte character size
When displayed or printed, double-byte characters usually are twice as wide as
single-byte characters.
Consider the width of double-byte characters when you calculate the length of a
double-byte data field because field lengths are usually identified as the number of
single-byte character positions used. For more information on calculating the
length of fields containing double-byte data, refer to the DDS Reference.