For gsub_file(), arguments passed to gsub(). For
other functions, arguments passed to gsub_file(). Note that the
argument x of gsub() is the content of the file.
rw_error
Whether to signal an error if the file cannot be read or
written. If FALSE, the file will be ignored (with a warning).
files
A vector of file paths.
dir
Path to a directory (all files under this directory will be
replaced).
recursive
Whether to find files recursively under a directory.
ext
A vector of filename extensions (without the leading periods).
mimetype
A regular expression to filter files based on their MIME
types, e.g., '^text/' for plain text files.