libxo is in practice a poor approach to generating structured output from unix utilities. There are at least a few problems. The format strings do not easily

libxo is in practice a poor approach to generating structured output from unix utilities. There are at least a few problems. The format strings do not easily replace existing formatted prints, so it is not straightforward to adopt. For anything more complicated than simple row records, you have to change the structure of your program significantly and might as well just use a different path for formatting structured output. It is unaware of locales, and as a result, butchers text in non ASCII/UTF-8 encodings. Finally, a separate-binary-with-structured-text-output is a poor library interface to quite a lot of these utilities -- a callable C API would be more broadly useful.