Vincent Lefevre wrote:
But both of these solutions have the drawback of working only in
UTF-8 locales.
Not at all; '[[:error:]]' would match a single-byte encoding error in
the current locale. The tz database is interested in UTF-8 so it sets
the LC_ALL environment variable to a UTF-8 locale, but that setting
shouldn't be required in general.
Also, the tz database needs grep patterns that iconv doesn't support.
For example, one rule is that commentary (which starts with #) can
contain UTF-8 characters, but the ordinary data (before the #) is
limited to a smaller set. This is captured by the command:
grep -Env '^[ordinarycharset]*(#.*)?$'
where 'ordinarycharset' is the set of ASCII characters in ordinary tz
data. Here it's useful that '.' does not match encoding errors on
GNU/Linux.
