Read source code from stdin, output formatted file to stdout.

Usage:
  v fmt [options] path_to_source.v [path_to_other_source.v]
  v fmt [options] path/to/dir [path/to/other_dir]
  cat source.v | v fmt

Formats the given V source files or recursively formats all files in the
directory, then prints their formatted source to stdout.

Options:
  -c             Check if a file is already formatted. If not, print the
                 filepath and exit with code 2. Compared to -verify it is
                 quicker but has a small trade-off in precision.

  -diff          Display the differences between the formatted source(s)
                 and the original source(s). This will attempt to find a
                 working `diff` command automatically unless you specify one
                 with the VDIFF_TOOL environment variable.

  -l             List files whose formatting differs from vfmt.

  -w             Write result to (source) file(s) instead of to stdout.

  -backup        In combination with `-w`, copy the original `file.v` to a
                 `file.v.bak` backup, before overwriting the original source
                 file.

  -debug         Print the kinds of encountered AST statements/expressions
                 on stderr.

  -verify        Make sure the provided file is already formatted. Useful for
                 checking code contributions in CI for example.

Environment Variables:
  VDIFF_TOOL     A command-line tool that will be executed with the original
                 file path and a temporary formatted file path as arguments.
                 e.g. `VDIFF_TOOL=opendiff v fmt -diff path/to/file.v` will
                 become: opendiff path/to/file.v /tmp/v/vfmt_file.v

  VDIFF_OPTIONS  A set of command-line options to be sent immediately after
                 the `diff` command. e.g. VDIFF_OPTIONS="-W 80 -y"
                 v fmt -diff path/to/file.v /tmp/v/vfmt_file.v
