rwall Command

Purpose

Sends messages to all users on the network.

Syntax

To Send a Message to Specified Hosts

/usr/sbin/rwall HostName ...

To Send a Message to Specified Networks

/usr/sbin/rwall -n NetworkGroup ...

To Send a Message to Specified Hosts on a Network

/usr/sbin/rwall -h HostName ... -n NetworkGroup

Description

The rwall command sends messages to all users on the network. To do this, the rwall command reads a message from standard input until it reaches an end-of-file character. The rwall command takes this message, which begins with the line Broadcast Message..., and broadcasts it to all users logged in to the specified host machines. Users receive messages only if they are running the rwalld daemon, which is started by the inetd daemon.

Note: The time out is fairly short. This enables the rwall command to send messages to a large group of machines (some of which may be down) in a reasonable amount of time. Thus the message may not get through to a heavily loaded machine.

Flags

Item Description
-h Sends the message to machines specified by the HostName parameter.
-n Sends the message to specific network groups only. Network groups are defined in the netgroup file.

Examples

  1. To send a message to a host named neptune, enter: 
    /usr/sbin/rwall neptune
    Type in your message. When you are done, enter: 
    Ctrl D
  2. To send a message to a host named neptune and every host in the cosmos netgroup, enter:

    rwall  -n cosmos  -h neptune

    Type in your message. When you are done, enter: 
    Ctrl D

Files

Item Description
/etc/inetd.conf TCP/IP configuration file that starts RPC daemons and other TCP/IP daemons.
/etc/netgroup Contains information about each user group on the network.