Foobar

Smokey Stover driving a "foomobile"

The etymology of foobar could be derived from the military slang from the World War II era FUBAR, which was bowdlerised to foobar.[2] The word foo on its own was used earlier. Between about 1930 and 1952 it appeared in the comic Smokey Stover by Bill Holman, who stated that, he used the word due to having seen it on the bottom of a jade Chinese figurine in San Francisco Chinatown, purportedly signifying "good luck".[3] If true this is related to the Chinese word fu ("福", sometimes transliterated foo), which can mean happiness or blessing.[2]

The first known use of the terms in print in a programming context appears in a 1965 edition of MIT's Tech Engineering News.[4] Foobar may have come about as a result of the pre-existing "Foo" being conjoined with "bar", an addition borrowed from the military's FUBAR. The use of foo in a programming context is generally credited to the Tech Model Railroad Club (TMRC) of MIT from circa 1960.[1] In the complex model system, there were scram switches located at numerous places around the room that could be thrown if something undesirable was about to occur, such as a train going full-bore at an obstruction. Another feature of the system was a digital clock on the dispatch board. When someone hit a scram switch, the clock stopped and the display was replaced with the word "FOO"; at TMRC the scram switches are, therefore, called "Foo switches". Because of this, an entry in the 1959 Dictionary of the TMRC Language went something like this: "FOO: The first syllable of the misquoted sacred chant phrase 'foo mane padme hum.' Our first obligation is to keep the foo counters turning."[5] One book describing the MIT train room describes two buttons by the door labeled "foo" and "bar". These were general purpose buttons and were often re-purposed for whatever fun idea the MIT hackers had at the time, hence the adoption of foo and bar as general-purpose variable names. An entry in the Abridged Dictionary of the TMRC Language states:[6]

Multiflush: stop-all-trains-button. Next best thing to the red door button. Also called FOO. Displays "FOO" on the clock when used.

The shift from the military expression FUBAR to foobar may also have been driven by the latter being a computer science pun. Since overbars designate repeating decimal numbers, the word foobar also signifies a number in hexadecimal, a base typically used in low-level programming. That number is 0.F00F00F00 ..., which equals the decimal fraction 256/273.

The term foobar was propagated through computer science circles in the 1960s and early 1970s by system manuals from Digital Equipment Corporation. Foobar was also used as a variable name in the Fortran code of Colossal Cave Adventure (1977 Crowther and Woods version). The variable FOOBAR was used to contain the player's progress in saying the magic phrase "Fee Fie Foe Foo". Intel also used the term foo in their programming documentation in 1978.[7]

In this Hello World code sample in C, foo and bar are used to illustrate string substitution:

#include <stdio.h>

int main() {
   const char *foo = "Hello";
   const char *bar = "World!";
   fprintf(stdout, "%s %s\n", foo, bar);

   return 0;
}

In this Scheme code sample, foobar is used to illustrate the name of a function:

(define foobar
   (lambda (x)
      (display x)))
(foobar "Hello World!")

In this Hello World code sample in Python, foo and bar are used to illustrate the names of the strings printed to STDOUT.

foo = "Hello"
bar = "World"
print(foo, bar)

• Foo Camp is an annual hacker convention.
• BarCamp, an international network of user-generated conferences
• During the United States v. Microsoft Corp. trial, some evidence was presented that Microsoft had tried to use the Web Services Interoperability organization as a means to stifle competition, including e-mails in which top executives including Bill Gates referred to the WS-I using the codename "foo".[8]
• foobar2000 is an audio player.
• Google uses a web tool called foobar to recruit new employees.[9]

• Foo fighter
• Foo was here
• xyzzy
• Category:Variable (computer science)

Look up foobar, foo, or bar in Wiktionary, the free dictionary.

• The Jargon File entry on "foobar", catb.org
• RFC 1639 – FTP Operation Over Big Address Records (FOOBAR)