Re: glib-2.2.1: g_print() with UTF-8 characters

[Owen Taylor <otaylor redhat com>]

On Sat, 2003-03-01 at 13:20, Ulf Karlsson wrote:
> Hi,
> 
> I'm trying to print strings containing swedish characters in columns
> by doing
> 
> 	g_print("%-16s%-16s\n", "Hallå", "Världen");
> 
> The problem seems to be that vasprintf isn't UTF-8-aware and counts
> the swedish UTF-8 character as two characters and thus only adds 10
> whitespaces after the first string, with the consequence that the
> second string is one position left of where it is supposed to be!

Notes here:

 - Glibc has a "feature" where %Ns actually checks for a whole 
   number of characters in the current encoding. So, unless you
   are sure you are always going to be in an UTF-8 locale, avoid
   using %Ns. (You are basically OK for iso-8859-1, but will
   have problems in say, a Japanese locale.)

 - If you want a certain number of columns, than neither number
   of characters or number of bytes works. A rough approximation
   is that if g_unichar_iswide(ch) is TRUE, then the character
   takes two columns, otherwise it takes one.

You'll probably want to write a function that takes a string
and pads/chops it to fit in a certain number of columns.

Regards,
                                        Owen