wall is a Unix command line utility. When invoked, it displays the contents of a file or standard input to all logged-in users. Its name is an abbreviation of "write to all".

Invocation

wall is invoked as follows:

foo@foo:~$ wall <filename>

To take standard input as the file, omit the filename.

Output

When invoked, wall displays the following output:

Broadcast Message from foo@lothlorien
  (/dev/pts/0) at 01:23 ...

This is the message that would be sent.

References

• wall(1): send message to everybody's terminal – Linux man page