The gecos field, or
GECOS
General Comprehensive Operating System (GCOS, ; originally GECOS, General Electric Comprehensive Operating Supervisor) is a family of operating systems oriented toward the 36-bit GE-600 series and Honeywell 6000 series mainframe computers.
The ...
field, is a field in each record in the
/etc/passwd file on
Unix
Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...
and similar
operating system
An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs.
Time-sharing operating systems scheduler (computing), schedule tasks for ...
s. On UNIX, it is the 5th of 7 fields in a record.
It is typically used to record general information about the account or its user(s) such as their real name and phone number.
Format
The typical format for the GECOS field is a comma-delimited list with this order:
#User's
full name
A personal name, full name or prosoponym (from Ancient Greek ''prósōpon'' – person, and ''onoma'' –name) is the set of names by which an individual person or animal is known. When taken together as a word-group, they all relate to that ...
(or application name, if the account is for a program)
#Building and room number or contact person
#Office
telephone number
A telephone number is the address of a Telecommunications, telecommunication endpoint, such as a telephone, in a telephone network, such as the public switched telephone network (PSTN). A telephone number typically consists of a Number, sequ ...
#Home telephone number
#Any other contact information (
pager
A pager, also known as a beeper or bleeper, is a Wireless communication, wireless telecommunications device that receives and displays Alphanumericals, alphanumeric or voice messages. One-way pagers can only receive messages, while response p ...
number,
fax
Fax (short for facsimile), sometimes called telecopying or telefax (short for telefacsimile), is the telephonic transmission of scanned printed material (both text and images), normally to a telephone number connected to a printer or other out ...
, external e-mail address, etc.)
In most UNIX systems non-root users can change their own information using the ''chfn'' or ''chsh'' command.
Here is an example of GECOS field within an /etc/passwd file in
Linux
Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...
:
History
Some early Unix systems at
Bell Labs
Nokia Bell Labs, commonly referred to as ''Bell Labs'', is an American industrial research and development company owned by Finnish technology company Nokia. With headquarters located in Murray Hill, New Jersey, Murray Hill, New Jersey, the compa ...
used
GECOS
General Comprehensive Operating System (GCOS, ; originally GECOS, General Electric Comprehensive Operating Supervisor) is a family of operating systems oriented toward the 36-bit GE-600 series and Honeywell 6000 series mainframe computers.
The ...
machines for
print spooling and various other services, so this field was added to carry information on a user's GECOS identity.
Other uses
On
Internet Relay Chat
IRC (Internet Relay Chat) is a text-based chat system for instant messaging. IRC is designed for Many-to-many, group communication in discussion forums, called ''#Channels, channels'', but also allows one-on-one communication via instant mess ...
(IRC), the real name field is sometimes referred to as the gecos field. IRC clients are able to supply this field when connecting.
Hexchat
HexChat is a discontinued Internet Relay Chat client and is a fork of ''XChat''. It has a choice of a tabbed document interface or tree interface, support for multiple servers, and numerous configuration options. Both command-line and graphi ...
, an
X-Chat fork, defaults to 'realname', TalkSoup.app on
GNUstep
GNUstep is a free software implementation of the Cocoa (formerly OpenStep) Objective-C frameworks, widget toolkit, and application development tools for Unix-like operating systems and Microsoft Windows. It is part of the GNU Project.
GNUst ...
defaults to 'David Okeamah', and
irssi
Irssi ( ) is an Internet Relay Chat (IRC) Client (computing), client program for Linux, FreeBSD, macOS and Microsoft Windows. It was originally written by Timo Sirainen, and released under the terms of the GNU General Public License, GNU GPL-2.0- ...
reads the operating system user's full name, replacing it with 'unknown' if not defined. Some IRC clients use this field for advertising; for example,
ZNC defaulted to "Got ZNC?", but changed it to "RealName = " to match its configuration syntax in 2015.
See also
*
General Comprehensive Operating System
General Comprehensive Operating System (GCOS, ; originally GECOS, General Electric Comprehensive Operating Supervisor) is a family of operating systems oriented toward the 36-bit GE-600 series and Honeywell 6000 series mainframe computers.
The ...
References
{{DEFAULTSORT:Gecos Field
Unix