|This article does not cite any references or sources. (October 2010)|
fortune is a simple program that displays a pseudorandom message from a database of quotations that first appeared in Version 7 Unix. The most common version on modern systems is the BSD fortune, originally written by Ken Arnold. Distributions of fortune are usually bundled with a collection of themed files, containing sayings like those found on fortune cookies (hence the name), quotations from famous people, jokes, or poetry.
fortune is predominantly found on Unix-like systems, but clients for other platforms also exist. Often, users on text-mode Unix terminals will place this command into either their .profile or .logout files to display them at logon and logout, respectively. It is also used to generate text input for certain XScreenSaver modes. Many people choose to pipe fortune into the cowsay command, to add more humor to the dialog.
Most Linux systems use a roughly equivalent set of fortune to other Unix types. The fortunes dispensed are slanted heavily toward the user base of Unix, and thus contain many obscure jokes about computer science and computer programming. Other favoured sources include quotations from science fiction (Star Trek, The Cyberiad, Doctor Who, The Hitchhiker's Guide to the Galaxy, etc.), Zippy the Pinhead, and the writings of Ambrose Bierce and Dave Barry. Most fortune collections also include a wide variety of more conventionally sourced quotations, jokes, and other short passages. A few distributions include so-called "offensive" dicta, which require the -a or -o options to be passed for viewing. These fortunes often include rude humor and profanity, and controversial comments about religion. This is why most Linux distributions do not install them by default, or when you install the program. Instead, they are provided by another package. However in FreeBSD, they are both installed at the same time, with no easy way to separate them. They are both installed when you select the 'games' package during installation. The exact fortunes vary between each type of Unix, however there seems to be a strong overlap between the FreeBSD and OpenBSD fortune files. The Plan 9 fortune files seem to be much shorter, with many just on 1 line, and the 'offensive' dicta is much stronger. Most Linux distributions, such as Ubuntu, choose the FreeBSD fortunes to put in their fortune packages, that can be installed through the package manager.
One of the included fortunes, from the "goedel" collection of fortunes about fortune itself, sums up the purpose of the program:
Has anyone realized that the purpose of the fortune cookie program is to defuse project tensions? When did you ever see a cheerful cookie, a non-cynical, or even an informative cookie? Perhaps inadvertently, we have a channel for our aggressions. This still begs the question [sic] of whether the cookie releases the pressure or only serves to blunt the warning signs. Long live the revolution! Have a nice day.
Fortune files 
Conventional versions of fortune use two files for each quotation list: a text file with quotations, each separated by the character "%" on its own line, and a random-access data file generated by the strfile(8) program. Alternative implementations, including those made for display on Web pages, typically use only the text file.
Common options 
Several common options exist that change the way command-line versions of fortune behave:
|-a||Choose from all databases, regardless of whether they are considered "offensive" or not|
|-e||Make the probability of choosing a fortune file equal to that of all other files|
|-f||Print out a list of all fortune files that would have been searched, but do not print a fortune|
|-i||When used with -m, make regular expression searching case-insensitive|
|-l||Use only quotations longer than the length specified with -n, or 160 characters if -n is not used|
|-m [pattern]||Print all fortunes matching the regular expression specified in [pattern]|
|-n [length]||Override the length used by -l and -s to determine "long" and "short" messages (default 160 characters)|
|-o||Choose only from "offensive" databases|
|-s||Use only quotations shorter than the length specified with -n, or 160 characters if -n is not used|
|-w||Wait for a period of time before terminating; useful for situations in which a fortune needs to be read before the screen is cleared|
See also 
- An archive of fortunes files from various systems.
- The manual page for the original Unix fortune(6) command.
- A manual page for the fortune program under Linux
- A simple online version of the Unix fortune program.
- Continuous web 'slide show' of fortunes
- A website that generates an RSS feed of random (but configurable) fortunes (especially for devices with simple RSS reader capabilities, e.g. VOIP phones)
- A PHP framework for reading and displaying fortune files
- ftp://ftp.ibiblio.org/pub/linux/games/amusements/fortune/ – source code for fortune-mod program
- A wiki containing all of the original non offensive fortunes
- An ASCII web comic that provides a fortune.txt feed of its content
- A simple fortune in PHP
- On-line fortunes with numerous fortune files to choose from