XMLStarlet Toolkit: query, edit, check, convert and transform XML documents. Some subcommands such as
xml validatehave their own usage documentation. More information: https://xmlstar.sourceforge.net/doc/UG/xmlstarlet-ug.html#idm47077139670224.
xml --help
stdout:xml {{subcommand}} {{options}} {{path/to/input.xml|URI}}
stdin and stdout:xml {{subcommand}} {{options}}
xml {{subcommand}} {{options}} {{path/to/input.xml|URI}} > {{path/to/output}}
xml {{subcommand}} --help
xml --version