Re: [libvirt] [PATCH v3 1/3] vsh: Add API for printing tables.

On Thu, 2018-08-16 at 12:28 +0100, Daniel P. Berrangé wrote: > On Thu, Aug 16, 2018 at 12:56:24PM +0200, Simon Kobyda wrote: >> > > After asking around I have found the right solution that we need to > use > for measuring string width. mbstowcs()/wcswidth() will get the > answer > wrong wrt zero-width characters, combining characters, non-printable > characters, etc. We need to use the libunistring library: > > > https://www.gnu.org/software/libunistring/manual/libunistring.html#uniwid... > > I've tried what you've suggested, but it seems that it doesn't work well with all unicode characters. I'm looking into the code of the library, and each function uN_strwidth calls function uN_width, and that function calls uc_width for calculation of width of characters. And if we look into the code of uc_width here: http://git.savannah.gnu.org/gitweb/?p=gnulib.git;a=blob;f=lib/uniwidth/wi... it seems that this library is limited only to certain unicodes, e.g.: hangul characters, angle brackets, CJK characters... But it doesn't cover all multiple-width characters. Example: I try to throw any emoji (e.g. 🙉, 🦀, 🏙), it returns width of 1 column for each charact er, nevertheless these characters have width of 2 columns on terminal. BTW, it seems unistring library imports those funcions from gnulib.