-i

The -i (simulate initial login) option runs the shell specified in the passwd(5) entry of the user that the command is being run as. The command name argument given to the shell begins with a `-' to tell the shell to run as a login shell. sudo attempts to change to that user's home directory before running the shell. It also initializes the environment, leaving TERM unchanged, setting HOME, SHELL, USER, LOGNAME, and PATH, and unsetting all other environment variables. Note that because the shell to use is determined before the sudoers file is parsed, a runas_default setting in sudoers will specify the user to run the shell as but will not affect which shell is actually run.