Lintr searches for settings for a given source file in the following order.
options defined as linter.setting.
linter_file in the same directory
linter_file in the project directory
linter_file in the user home directory
default_settings()
read_settings(filename)source file to be linted
The default linter_file name is .lintr but it can be changed with option lintr.linter_file
or the environment variable R_LINTR_LINTER_FILE
This file is a dcf file, see base::read.dcf() for details.