linux--Network communication Command (send broadcast messages to other users)

1. Command name: Write
Execute permissions: All user function Description: Send a message to another user with Ctrl+d as the end
Syntax: Write < user name >
Root sends messages to LUXH users
[Email protected] ~]# Write Luxh
WRITE:LUXH is logged in more than once; Writing to PTS/1
Hello,luxh,i am Root

The information received by the user luxh is
[Email protected] ~]$
Message from [e-mail protected] (as root) on pts/0 at 05:17 ...
Hello,luxh,i am Root

The root user sends a message to the LUXH user, luxh the user must have logged in (that is, remote connection up, I tried su-user not), otherwise it is not sent.

2. Command name: Wall
Execute permissions: All user function Description: Broadcast information to all users
Grammar:wall [message] [file name]

Root sends messages to all logged-in users
[Email protected] ~]# Wall Happy New Year
Broadcast message from [email protected] (pts/0) (Thu Nov 22 05:27:49 2012):
Happy New Year

Users who have logged in will be able to receive
[Email protected] ~]$
Broadcast message from [email protected] (pts/0) (Thu Nov 22 05:27:49 2012):

Happy New Year

linux--Network communication Command (send broadcast messages to other users)