WRITE(1) User Commands WRITE(1)

NAME

write - write to another user

SYNOPSIS

write user [terminal]

DESCRIPTION

The write utility reads lines from the user's standard input and
writes them to the terminal of another user. When first invoked, it
writes the message:

Message from sender-login-id (sending-terminal) [date]...


to user. When it has successfully completed the connection, the
sender's terminal will be alerted twice to indicate that what the
sender is typing is being written to the recipient's terminal.


If the recipient wants to reply, this can be accomplished by typing

write sender-login-id [sending-terminal]


upon receipt of the initial message. Whenever a line of input as
delimited by a NL, EOF, or EOL special character is accumulated while
in canonical input mode, the accumulated data will be written on the
other user's terminal. Characters are processed as follows:

o Typing the alert character will write the alert character
to the recipient's terminal.

o Typing the erase and kill characters will affect the
sender's terminal in the manner described by the
termios(3C) interface.

o Typing the interrupt or end-of-file characters will cause
write to write an appropriate message (EOT\n in the C
locale) to the recipient's terminal and exit.

o Typing characters from LC_CTYPE classifications print or
space will cause those characters to be sent to the
recipient's terminal.

o When and only when the stty iexten local mode is enabled,
additional special control characters and multi-byte or
single-byte characters are processed as printable
characters if their wide character equivalents are
printable.

o Typing other non-printable characters will cause them to
be written to the recipient's terminal as follows: control
characters will appear as a `^' followed by the
appropriate ASCII character, and characters with the high-
order bit set will appear in "meta" notation. For example,
`\003' is displayed as `^C' and `\372' as `M-z'.


To write to a user who is logged in more than once, the terminal
argument can be used to indicate which terminal to write to.
Otherwise, the recipient's terminal is the first writable instance of
the user found in /usr/adm/utmpx, and the following informational
message will be written to the sender's standard output, indicating
which terminal was chosen:

user is logged on more than one place.
You are connected to terminal.
Other locations are:terminal


Permission to be a recipient of a write message can be denied or
granted by use of the mesg utility. However, a user's privilege may
further constrain the domain of accessibility of other users'
terminals. The write utility will fail when the user lacks the
appropriate privileges to perform the requested action.


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.


write runs setgid() (see setuid(2)) to the group ID tty, in order to
have write permissions on other users' terminals.


The following protocol is suggested for using write: when you first
write to another user, wait for them to write back before starting to
send. Each person should end a message with a distinctive signal
(that is, (o) for over) so that the other person knows when to reply.
The signal (oo) (for over and out) is suggested when conversation is
to be terminated.

OPERANDS

The following operands are supported:

user
User (login) name of the person to whom the message will
be written. This operand must be of the form returned by
the who(1) utility.


terminal
Terminal identification in the same format provided by
the who utility.

ENVIRONMENT VARIABLES

See environ(7) for descriptions of the following environment
variables that affect the execution of write: LANG, LC_ALL, LC_CTYPE,
LC_MESSAGES, and NLSPATH.

EXIT STATUS

The following exit values are returned:

0
Successful completion.


>0
The addressed user is not logged on or the addressed user
denies permission.

FILES

/var/adm/utmpx
User and accounting information for write


/usr/bin/sh
Bourne shell executable file

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+-------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-------------------+
|CSI | Enabled |
+--------------------+-------------------+
|Interface Stability | Committed |
+--------------------+-------------------+
|Standard | See standards(7). |
+--------------------+-------------------+

SEE ALSO

mail(1), mesg(1), pr(1), sh(1), talk(1), who(1), setuid(2),
termios(3C), attributes(7), environ(7), standards(7)

DIAGNOSTICS

user is not logged on

The person you are trying to write to is not logged on.


Permission denied

The person you are trying to write to denies that permission
(with mesg).


Warning: cannot respond, set mesg-y

Your terminal is set to mesg n and the recipient cannot respond
to you.


Can no longer write to user

The recipient has denied permission (mesg n) after you had
started writing.


November 3, 2000 WRITE(1)