The term code page is used to refer to a number
of different concepts. Conversely, the set of concepts to which code
page can refer can also be described by a number of other terms. The
concept and implementation of code pages also differ significantly between
Windows, Linux, and the UNIX system.
To describe the types of character data that users can enter and store
in an IBM Rational® ClearQuest® environment,
this discussion uses the following terms in the following ways:
- A national language support (NLS) provides commands and library
subroutines for a single worldwide system base. In the context of Rational ClearQuest, NLS refers
to the ability of Rational ClearQuest applications
and databases to input and output data consisting of characters from any of
the supported Rational ClearQuest data
code pages.
- The term character set refers to a set of characters that
a computer application or system supports.
- The term code page, refers to a character set and the binary
values that represent those characters. A computer or application can use
code pages to work with these characters:
- Only the 128 characters of the ASCII character set (suitable for American
English).
- Additional characters used by Eastern and Western European languages,
such as "ä" for German, Swedish and Finnish and "È" for French and Spanish,
and so on.
- Characters from non-European languages such as Hebrew, Japanese, and Chinese.
- Additional characters required by other languages.
- The term vendor database character set refers to a character
set that the database management system (DBMS) vendor allows to be stored
in the databases for the Rational ClearQuest schema
repository and user data. Individual DBMS vendors use code page, code
set, collation, and charset as synonyms for
this term.
- The term Rational ClearQuest data
code page refers to character set that Rational ClearQuest can
store in a Rational ClearQuest database
set. This character set is equivalent to or a subset of the corresponding
vendor database character set. To set the data code page, you must select
the value compatible with the vendor database character set that is configured
for the vendor database. A schema repository can support only one data code
page.
- The term local character set (generally called the locale on
Linux and the UNIX systems) refers to the character set that can be entered
or displayed in a command-line shell on the system that runs a Rational ClearQuest application,
for example, the Maintenance Tool, Designer, or Rational ClearQuest client.
On Linux or the UNIX system , the local character set is controlled by the
LANG environment variable. On Windows, it is controlled by settings in the
Regional and Language Options. Other character sets can be displayed if additional
fonts are configured. Also, additional character data may be entered through
an input method editor (IME) or by cutting and pasting text to the Rational ClearQuest GUI applications.