How to broadcast a message to all users and direct message to some user

Administrators have several ways to send messages to everyone logged in to a text-mode system. This article introduces two simple methods: broadcasting a message to all logged-in users and sending a message directly to a particular user. Both methods are described below.

1. Broadcasting a message to all logged-in users Use “wall” to broadcast the message, and “echo” to print the text you want to send. Command syntax

   [user1Ezylinux ~]$ echo -e "Text for send" | wall

   The message every user receives

   Broadcast message from [email protected] (Mon Nov 14 21:13:06 2011):
   
   Text for send

   To include line breaks, add “\n” at the end of each line. Example

   [user1Ezylinux ~]$ echo -e 'Message1 \nMessage2' |wall
   
   Broadcast message from [email protected] (Mon Nov 14 21:13:18 2011):
   
   Message1
   Message2

2. Sending a message directly to a particular user First find the TTY on which the intended recipient is logged in using “w”.

   
   [user1Ezylinux ~]$ w
    21:50:47 up 58 days, 21:27,  3 users,  load average: 0.00, 0.00, 0.00
   USER      TTY      FROM             LOGIN@   IDLE   JCPU   PCPU WHAT
   user1     pts/1    56.7.8.8         20:57    0.00s  0.04s  0.00s w
   user2     pts/2    56.7.8.9         20:57   37:29   0.00s  0.00s -bash
   user3     pts/3    56.7.8.10        21:13   26:25   0.00s  0.01s sshd: user3 [priv]

   Look at the TTY column to identify the user’s pts or tty. Then use “echo” to send text to /dev/pts/n, where n is the terminal number. For example, I am user1 and want to send “Message1” directly to user2. The output of “w” shows that user2 is on pts/2, so use this command:

   
   [user1Ezylinux ~]$ echo -e "\nMessage1" > /dev/pts/2

   user2 receives the following message:

   
   [user2Ezylinux ~]$
   Message1