WRITE(1) General Commands Manual WRITE(1)
write - write to another user
write user [ ttyname ]
Write copies lines from your terminal to that of another user. When
first called, it sends the message
Message from yourname yourttyname...
The recipient of the message should write back at this point. Communi-
cation continues until an end of file is read from the terminal or an
interrupt is sent. At that point write writes `EOT' on the other ter-
minal and exits.
If you want to write to a user who is logged in more than once, the
ttyname argument may be used to indicate the appropriate terminal name.
Permission to write may be denied or granted by use of the mesg com-
mand. At the outset writing is allowed. Certain commands, in particu-
lar nroff and pr(1) disallow messages in order to prevent messy output.
If the character `!' is found at the beginning of a line, write calls
the shell to execute the rest of the line as a command.
The following protocol is suggested for using write: when you first
write to another user, wait for him to write back before starting to
send. Each party should end each message with a distinctive sig-
nal--(o) for `over' is conventional--that the other may reply. (oo)
for `over and out' is suggested when conversation is about to be termi-
/etc/utmp to find user
/bin/sh to execute `!'
mesg(1), who(1), mail(1)