How does Linux send information to all users who log on to the server?

Wind Network (ithov.com) original article: In the management of Linux users, sometimes the administrator needs to send a message to all landing users or notifications, we can achieve through the wall command, the following steps:

1 Input wall and enter

2 Enter the message to send

3 at the end of the "control-d" button, the message is displayed in the User's control window

Example：

[Root@localhost ~]# Wall
Wind Network (www.ithov.com) welcome you to visit, scheduled for July 1, the server routine maintenance, is expected to take 20 minutes, please before June 31 to back up the important information, thank you for your cooperation!

Then press CTRL and the information will be sent to every user on the landing server, as follows:

Broadcast message from Root@localhost.localdomain (pts/0) (Mon jul&http://www.aliyun.com/zixun/aggregation/37954.html ">nbsp"; 1 07:44:09 2013):

Wind Network (www.ithov.com) welcome you to visit, scheduled for July 1, the server routine maintenance, is expected to take 20 minutes, please before June 31 to back up the important information, thank you for your cooperation!