HP-UX 11i Release Notes (December 2000)

New and Changed Internationalization Features
Multibyte Support Extension and Unix98 Support (new)
Chapter 15308
Multibyte Support Extension and Unix98
Support (new)
A new set of multibyte APIs have been added to libc following the C99
specification (ISO/IEC 9899:1999), and the Unix98 specification.
These APIs extend the already existing multibyte and wide character
APIs in order to be able to:
• perform input and output of wide character, or multibyte character, or
both
• perform general wide string manipulation
• provide extended capabilities for conversion between multibyte and
wide character sequences
Several new design concepts have been introduced:
• Stream orientation
• Restartable APIs and the conversion state
Stream Orientation
A stream can be either wide-character or byte-oriented. The orientation
of a stream is a concept based on an input/output model that assumes
that characters are handled as wide characters within an application
and stored as multibyte characters in files, and that all the
wide-character input/output functions begin executing with the stream
positioned at the boundary between two multibyte characters.
After a stream is associated with a file, but before any operations are
performed on the stream, the stream is without orientation. If a
wide-character input or output function is applied to a stream without
orientation, the stream becomes wide-oriented implicitly. Likewise, if a
byte input or output operation is applied to a stream without orientation,
the stream becomes byte-oriented implicitly. Once the stream becomes
oriented, the orientation is fixed and cannot be changed until the stream
is closed.