FreeTDS Development Group

[Steve Langasek <vorlon AT netexpress.net>]

On Sun, 10 Jun 2001, Brian Bruns wrote:

> dblib, ct-lib, and ODBC all ride atop libtds.  So they are all on equal
> footing regarding access to those nuances. Sybase on the other hand, has
> ODBC sit atop ct-lib which makes in rather inefficient.

> This stuff has my head spinning... I tried to look into how dblib and
> ctlib may handle multibyte character sets but didn't particularly turn up
> anything.  The Sybase International Developer's Guide was a little opaque
> on the matter.

Hmm... I found the information at 
<http://manuals.sybase.com:80/onlinebooks/group-cn/cng1110e/i_and_l/@Generic__BookTextView/986;pt=988#X>
rather enlightening.  ct-lib does have the concept of locales, and provides
ample functions for changing the locale of a given connection.  Well, under
glibc, it's possible to supply the desired charset /as part of the locale
name/.  Doing the same thing in FreeTDS would allow specifying a 'traditional'
default charset for each language, and also allow client apps to explicitly
choose UTF-8 support with a locale string such as 'en_US.UTF-8' or
'ko_KR.UTF-8'.

OpenClient appears to make heavy use of a 'locales' file on the system to let
system administrators customize the list of available preset locales.  On
systems that have good l10n support in the C library, this may be overkill.
Do enough people depend on this particular behavior of ctlib to make it worth
emulating?

I'm not certain if/how glibc exposes charset information to applications.
I'll gladly look into this, and find out if there's an easy way to get the
name of a default charset given a locale name in ll_CC format.

Steve Langasek
postmodern programmer