WRITE (I) 3/15/72 WRITE (I)
NAME write -- write to another user
SYNOPSIS write user
DESCRIPTION write copies lines from your typewriter to that
of another user. When first called, write sends
the message
message from yourname...
The recipient of the message should write back at
this point. Communication continues until an end
of file is read from the typewriter or an inter-
rupt is sent. At that point write writes "EOT"
on the other terminal.
Permission to write may be denied or granted by
use of the mesg command. At the outset writing
is allowed. Certain commands, in particular roff
and pr, disallow messages in order to prevent
messy output.
If the character "!" is found at the beginning of
a line, write calls the mini-shell msh 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 dis-
tinctive signal ("(o)" for "over" is conven-
tional) that the other may reply. "(oo)" (for
"over and out") is suggested when conversation is
about to be terminated.
FILES /tmp/utmp to find user
/etc/msh to execute !
SEE ALSO mesg(I), msh(VII)
DIAGNOSTICS "user not logged in"; "permission denied".
BUGS write should check the mode of the other user's
typewriter and refuse to proceed unless non-user
write permission is given. Currently it is pos-
sible to write to another person with the same
user-ID even though he has forbidden messages.
write should also allow specification of the
typewriter name of a user who is logged in sev-
eral times instead of picking out the instance
with the lowest name.