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Original author(s)Dennis Ritchie,
Ken Thompson
Developer(s)AT&T Bell Laboratories
Initial releaseNovember 3, 1971; 50 years ago (1971-11-03)
Operating systemUnix and Unix-like

In Unix and Unix-like operating systems, write is a utility used to send messages to another user by writing a message directly to another user's TTY.[1]


The write command was included in the First Edition of the Research Unix operating system.[2] A similar command appeared in Compatible Time-Sharing System.[3]

Sample usage

The syntax for the write command is:

$ write user [tty]

The write session is terminated by sending EOF, which can be done by pressing Ctrl+D. The tty argument is only necessary when a user is logged into more than one terminal.[4]

A conversation initiated between two users on the same machine:

$ write root pts/7

Will show up to the user on that console as:

Message from root@wiki on pts/8 at 11:19 ...

See also


  1. ^ write(1) – Version 7 Unix Programmer's Manual
  2. ^ Unix Programmer's Manual (PDF) (1st ed.). Bell Labs. 3 November 1971. p. write(1). Archived from the original (PDF) on 9 July 2016. Retrieved 9 July 2016.
  3. ^ Fetter, Mirko (2019). New Concepts for Presence and Availability in Ubiquitous and Mobile Computing. University of Bamberg Press. p. 38. ISBN 9783863096236. The basic concept of sending instantaneously messages to logged in users came with ... CTSS ...
  4. ^ write(1) – util-linux man page