AIX Version 4.3 Differences Guide

• __mblen_std() - For all other code sets, use the __mbtowc_std()
method to determine the number of bytes in the character by calling
the appropriate iconv() converter and seeing how many bytes were
able to be converted.
mbstopcs() Convert multi-byte string to process code string. This function is
somewhat obsolete, as mbstowcs() is the preferred alternative.
There is one standard locale method, __mbstopcs_std(), which
loops through the multi-byte string calling mbtopc() to convert each
multi-byte character to the appropriate process code.
mbstowcs() Convert multi-byte string to wide character string. There is one
standard locale method, __mbstowcs_std(), which loops through
the multi-byte string calling mbtowc() to convert each multi-byte
character to the appropriate wide character.
mbtopc()
Convert multi-byte character to process code. This function is
somewhat obsolete, as its function is duplicated by the mbtowc()
function. There is one standard locale method, __mbtopc_std(),
which calls mbtowc() to perform the intended function of converting
the multi-byte character to process code (wide character).
mbtowc() Convert multi-byte character to wide character. All of the provided
mbtowc() methods convert the multi-byte character to a Unicode
value. There are three different methods provided in order to
optimize performance of this operation based on the nature of the
multi-byte codeset:
• __mbtowc_iso1() - Since ISO8859-1 is a proper subset of Unicode.
Its data can be converted to Unicode by simply casting its 8-bit
value to a 16-bit value. This is the fastest method for converting
ISO8859-1 to Unicode.
• __mbtowc_utf() - UTF-8-based data can be converted to Unicode
by using a simple bit-shifting algorithm. This method should be
used for all UTF-8 based locales since it is faster than the
__mbtowc_std() method listed below.
• __mbtowc_std() - For all other codesets, the __mbtowc_std()
method converts the multi-byte data to Unicode using the iconv()
interface. The conversion descriptor is defined as a static pointer so
that multiple calls to __mbtowc_std() will not incur the overhead of
multiple iconv_open() calls. Because this locale method is
dependent on libiconv, it has been placed into a common locale
method object in /usr/lib/nls/loc/methods/stdmeth.o instead of in the
libc library, to avoid creating an unnecessary dependency between
libc and libiconv.
pcstombs() This method is obsolete since its function has been replaced by the
method wcstombs(). Currently, this function just returns -1.
pctomb()
This method is obsolete since its function has been replaced by the
method wctomb(). Currently, this function just returns -1.
wcstombs() Convert wide character string to multi-byte string. There is one
standard locale method __wcstombs_std(), which loops through the
wide character string calling wctomb() to convert each wide
character to the appropriate multi-byte string.
246 AIX Version 4.3 Differences Guide