making sure it is started form rc...

Ludzie pragną czasami się rozstawać, żeby móc tęsknić, czekać i cieszyć się z powrotem.

inet2, the portmapper doesn't require any conguration
work.
9.5. Conguring the r Commands
156
9.5 Conguring the r Commands
There are a number of commands for executing commands on remote hosts. These are
rlogin, rsh, rcp and rcmd. They all spawn a shell on the remote host and allow the user
to execute commands. Of course, the client needs to have an account on the host where
the commmand is to be executed. Thus all these commands perform an authorization
procedure. Usually, the client will tell the user's login name to the server, which in turn requests a password that is validated in the usual way.
Sometimes, however, it is desirable to relax authorization checks for certain users. For
instance, if you frequently have to log into other machines on your LAN, you might want
to be admitted without having to type your password every time.
Disabling authorization is advisable only on a small number of hosts whose password
databases are synchronized, or for a small number of privileged users who need to access
many machines for administrative reasons. Whenever you want to allow people to log
into your host without having to specify a login id or password, make sure that you don't
accidentally grant access to anybody else.
There are two ways to disable authorization checks for the r commands. One is for the
super user to allow certain or all users on certain or all hosts (the latter denitely being a bad idea) to log in without being asked for a password. This access is controlled by a
le called /etc/hosts.equiv. It contains a list of host and user names that are considered
equivalent to users on the local host. An alternative option is for a user to grant other users on certain hosts access to her account. These may be listed in the le .rhosts in the user's home directory. For security reasons, this le must be owned by the user or the super user, and must not be a symbolic link, otherwise it will be ignored.3
When a client requests an r service, her host and user name are searched in the
/etc/hosts.equiv le, and then in the .rhosts le of the user she wants to log in as. As
am example, assume janet is working on gauss and tries to log into joe's account on eu-
ler. Throughout the following, we will refer to Janet as the client user, and to Joe as the local user. Now, when Janet types
$ rlogin -l joe euler
on gauss, the server will rst check hosts.equiv if Janet should be granted free access, and 4
if this fails, it will try to look her up in .rhosts in joe's home directory.
The hosts.equiv le on euler looks like this:
3
In an NFS environment, you may need to give it a protection of 444, because the super user is often very restricted in accessing les on disks mounted via NFS.
4
Note that the hosts.equiv le is not searched when someone attempts to log in as root.
9.5. Conguring the r Commands
157
gauss
euler
-public
quark.physics.groucho.edu
andres
An entry consists of a host name, optionally followed by a user name. If a host name
appears all by itself, all users from that host will be admitted to their local accounts without any checks. In the above example, Janet would be allowed to log into her account janet
when coming from gauss, and the same applies to any other user except root. However, if
Janet wants to log in as joe, she will be prompted for a password as usual.
If a host name is followed by a user name, as in the last line of the above sample le,
this user is given password-free access to all accounts except the root account.
The host name may also be preceded by a minus sign, as in the entry \-public". This
requires authorization for all accounts on public, regardless of what rights individual users grant in their .rhosts le.
The format of the .rhosts le is identical to that of hosts.equiv, but its meaning is a little dierent. Consider Joe's .rhosts le on euler:
chomp.cs.groucho.edu
gauss
janet
The rst entry grants joe free acess when logging in from chomp.cs.groucho.edu, but
does not aect the rights of any other account on euler or chomp. The second entry is a
slight variation of this, in that it grants janet free access to Joe's account when logging in from gauss.
Note that the client's host name is obtained by reverse mapping the caller's address to