The word foobar is commonly used in programming and computer science circles. The word has many uses, although it is also often mistaken with the acronym "FUBAR." The technically correct uses foobar vary, one being a specific acronym for a File Transfer Protocol operation, and the other being a generic term used primarily for examples.
Replacement Word
The term foobar is used in some computer science and programming circles as a replacement for file names and specific commands during demonstrations. For example, when demonstrating some of the image file extensions, an instructor may demonstrate file names like "foobar.png," "foobar.jpg," and "foobar.gif." For commands, an example could include something as simple as changing directories in the command prompt, which would be demonstrated as "cd files/foobar" or something similar.
RFC 1639
RFC 1639 is an FTP protocol that gains its "foobar" acronym from its other name: FTP Operation Over Big Address Records. It was first laid out an an experimental protocol for specifying address families other than the default internet address family in FTP commands and replies. It was laid out by David Piscitello of Core Competence, Inc. in 1994.
Confusion with FUBAR
Sometimes, foobar is mistakenly thought to be interchangeable with, or an alternate spelling of FUBAR. FUBAR is a military slang acronym for F***ed Up Beyond All Recognition. It refers to something that is severely out of sorts, damaged, or otherwise irregular or anomalous, generally to the point of being irreparable. Generally, few in the computer science, programming or hacking community apply this meaning to "foobar."
Alternate Uses
Occasionally, foobar is broken down into two words, "foo" and "bar." These individual words are used similarly to foobar itself when used as a replacement word, making multiple file names or commands possible with more than one distinct example name. Sometimes the term is also used in electronics to refer to an inverted foo signal, where a digital signal is coded to have a positive charge or an otherwise high current condition that represents a one. This causes a horizontal bar over the signal label, earning the signal the name "foo bar." Foo is also used by $foo, a German Perl programming magazine. According to CNET, "foo" was also used by Microsoft as a codeword the Web Services Interoperability Organization (WS-I) before the group was officially founded.
Tags: also used, computer science, file names, computer science programming, foobar foobar