[Guest 80 247 100]

[pre]
`-'
`-l'
`--login'
    Make the shell a login shell.  This means the following.  Unset all
    environment variables except `TERM', `HOME', and `SHELL' (which
    are set as described above), and `USER' and `LOGNAME' (which are
    set, even for the super-user, as described above), and set `PATH'
    to a compiled-in default value.  Change to USER's home directory.
    Prepend `-' to the shell's name, intended to make it read its
    login startup file(s).
[/pre]