wall — write a message to all users
−t timeout ] [ message | file ]
or the contents of a
file, or otherwise its standard
input, on the terminals of all currently logged in users. The
command will wrap lines that are longer than 79 characters.
Short lines are whitespace padded to have 79 characters. The
command will always put a carriage return and new line at the
end of each line.
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.
Reading from a
file is refused when the
invoker is not superuser and the program is suid or sgid.
Suppress the banner.
Abandon the write attempt to the terminals after
timeout must be a
positive integer. The default value is 300 seconds,
which is a legacy from the time when people ran
terminals over modem lines.
Display version information and exit.
Display help text and exit.
Some sessions, such as wdm, that have in the beginning of utmp(5) ut_type data a ':' character will not get the message from wall. This is done to avoid write errors.
The wall command is part of the util-linux package and is available from Linux Kernel Archive
Copyright (c) 1989, 1990 The Regents of the University of California.
All rights reserved.
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This product includes software developed by the University of
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(#)wall.1 6.5 (Berkeley) 4/23/91