wall (Unix)

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. To write the text to send just before, combine it with the "echo" command :

foo@foo:~$ echo text to send |wall

Alternatively, typing wall then enter, typing any text and pressing CTRL + D gives the same result:

foo@foo:~$ wall
text to send
on as many lines as neccesary
^D

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: send message to everybody's terminal – Shell and Utilities Reference, The Single UNIX Specification, Version 4 from The Open Group