wall(1) [opendarwin man page]
WALL(1) User Commands WALL(1) NAME
wall - write a message to all users SYNOPSIS
wall [-n] [-t timeout] [-g group] [message | file] DESCRIPTION
wall displays a message, 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 set-user-ID or set-group-ID. OPTIONS
-n, --nobanner Suppress the banner. -t, --timeout timeout Abandon the write attempt to the terminals after timeout seconds. This 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. -g, --group group Limit printing message to members of group defined as a group argument. The argument can be group name or GID. -V, --version Display version information and exit. -h, --help Display help text and exit. NOTES
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. SEE ALSO
mesg(1), talk(1), write(1), shutdown(8) HISTORY
A wall command appeared in Version 7 AT&T UNIX. AVAILABILITY
The wall command is part of the util-linux package and is available from Linux Kernel Archive <https://www.kernel.org/pub/linux/utils/util- linux/>. util-linux August 2013 WALL(1)
Check Out this Related Man Page
WRITE(1) BSD General Commands Manual WRITE(1) NAME
write -- send a message to another user SYNOPSIS
write user [tty] DESCRIPTION
The write utility allows you to communicate with other users, by copying lines from your terminal to theirs. When you run the write command, the user you are writing to gets a message of the form: Message from yourname@yourhost on yourtty at hh:mm ... Any further lines you enter will be copied to the specified user's terminal. If the other user wants to reply, they must run write as well. When you are done, type an end-of-file or interrupt character. The other user will see the message 'EOF' indicating that the conversation is over. You can prevent people (other than the super-user) from writing to you with the mesg(1) command. If the user you want to write to is logged in on more than one terminal, you can specify which terminal to write to by specifying the termi- nal name as the second operand to the write command. Alternatively, you can let write select one of the terminals - it will pick the one with the shortest idle time. This is so that if the user is logged in at work and also dialed up from home, the message will go to the right place. The traditional protocol for writing to someone is that the string '-o', either at the end of a line or on a line by itself, means that it is the other person's turn to talk. The string 'oo' means that the person believes the conversation to be over. SEE ALSO
mesg(1), talk(1), wall(1), who(1) HISTORY
A write command appeared in Version 1 AT&T UNIX. BUGS
The sender's LC_CTYPE setting is used to determine which characters are safe to write to a terminal, not the receiver's (which write has no way of knowing). BSD February 13, 2012 BSD