For txt, I let it stay similar format to the msg tool. That means one lang one txt file. For csv, I put all the languages into one file, with the msg entry name, its guid, and attributes. I think this ...
The arguments are as follows. Usage: xml2csv [flags] Flags -i, --input string XML input file path or directory or url -m, --mapping string XML to CSV mapping file path or url -o, --output string CSV ...