rcmd(TC)                        19 June 1992                        rcmd(TC)


 Name

    rcmd - remote shell command execution

 Syntax

    rcmd node [-l user] [-n] [command]

    /usr/hosts/node [-l user] [-n] [command]

 Description

    rcmd sends command to node for execution.  It passes the resulting remote
    command its own standard input and outputs the remote command's standard
    output and standard error.  Command can consist of more than one parame-
    ter.  The second, simplified form of the command is equivalent to the
    first, but is only available if the system administrator previously ran
    mkhosts(ADMN).  Interrupt, quit, and terminate signals received by rcmd
    are also received by the remote command; rcmd normally terminates at the
    same time as the remote command.

    If command is omitted, rcmd simply runs rlogin(TC).

    By default, the command belongs to the user on the remote node with the
    same name as the user who ran rcmd.  This means that the resulting pro-
    cesses belong to the remote user and begin with the remote user's home
    directory as their working directory.  Options permit you to specify
    another user on node as the owner.  In any case, the remote system must
    have declared the local user equivalent to the remote user: an entry in
    /etc/hosts.equiv or in a .rhosts file in the current directory (normally
    the home directory) of the target user will demonstrate equivalence.
    (See rcmd(SLIB)).

    rcmd understands the following options:

       -l user   The command is to belong to user on node.

       -n        Prevent the remote command from blocking on input by making
                 its standard input be /dev/null instead of rcmd's standard
                 input.

                 If -n is not specified, rcmd reads the local standard input
                 regardless of whether the remote machine reads standard
                 input.

 Files


    $HOME/.rhosts    (on the target machine)

    /etc/hosts.equiv (on the target machine)

 Examples

    The following command runs who on a node called ``central,'' putting the
    output in a file on the local machine.

       rcmd central who > /tmp/c.who

    The next example puts the same output on the remote machine.

       rcmd central who \> /tmp/c.who


 Requirements

    rshd(ADMN) must be running on the target machine.

 Notes

    In some installations, this command is called rsh, so as to be like other
    versions of the software.

 Warnings

    As the above examples illustrate, metacharacters to be interpreted by the
    remote shell must be hidden from the local shell.  Thus

       rcmd central cd /etc ; cat passwd

    clearly does not do what was intended because the semicolon is inter-
    preted by the local shell, not the remote shell, and the remote shell
    never even sees the cat command.  Either of the following commands prop-
    erly escapes the semicolon:

       rcmd central cd /etc \; cat passwd
       rcmd central 'cd /etc ; cat passwd'


 See also

    mkhosts(ADMN), rlogin(TC), rshd(ADMN), rhosts(SFF).