— write a
message to users
displays the contents of
, or, by default, its standard input, on
the terminals of all currently logged in users.
Only the superuser can write on the terminals of users who have chosen to deny
messages or are using a program which automatically denies messages.
The options are as follows:
- Send messages to users in this group. This option may be
specified multiple times, and any user in any of the specified groups will
receive the message.
Since the sender's locale(1)
not match the receivers' locales, wall
deliberately ignores the
environment variable and allows ASCII printable and space characters only.
Non-printable characters and UTF-8 characters are replaced with question
command appeared in
Version 7 AT&T UNIX