Editing File (command) (section)

==History==
The <code>file</code> command originated in [[Unix Research Version 4]]<ref>{{cite web|url=https://minnie.tuhs.org/cgi-bin/utree.pl?file=V4/man/man1/file.1|title=Source of the UNIX V4 "file" man page|access-date=2022-03-13|archive-date=2019-12-10|archive-url=https://web.archive.org/web/20191210000719/https://minnie.tuhs.org/cgi-bin/utree.pl?file=V4%2Fman%2Fman1%2Ffile.1|url-status=live}}</ref> in 1973. [[System V]] brought a major update with several important changes, most notably moving the file type information into an external text file rather than compiling it into the binary itself.

Most major [[BSD]] and [[Linux]] distributions include a [[free software|free]], [[open-source software|open-source]] implementation that was written from scratch by Ian Darwin in 1986–87.<ref>The early history of this program is recorded in its private CVS repository; see [https://www.darwinsys.com/file/file.c.log.txt] {{Webarchive|url=https://web.archive.org/web/20170401080455/https://www.darwinsys.com/file/file.c.log.txt |date=2017-04-01 }} the log of the main program</ref> It keeps file type information in a text file with a format based on that of the System V version. It was expanded by [[Geoff Collyer]] in 1989 and since then has had input from many others, including Guy Harris, Chris Lowth and Eric Fischer. From late 1993 onward, its maintenance has been organized by Christos Zoulas. The [[OpenBSD]] system has its own subset implementation written from scratch, but still uses the Darwin/Zoulas collection of magic file formatted information.

The {{code|file}} command was ported to the [[IBM i]] operating system.<ref>{{cite web |title=IBM System i Version 7.2 Programming Qshell |language=en |website=[[IBM]] |url=https://www.ibm.com/support/knowledgecenter/ssw_ibm_i_74/rzahz/rzahzpdf.pdf?view=kc |access-date=2020-09-05 |archive-date=2021-03-05 |archive-url=https://web.archive.org/web/20210305180649/https://www.ibm.com/support/knowledgecenter/ssw_ibm_i_74/rzahz/rzahzpdf.pdf?view=kc |url-status=live }}</ref>

As of version 4.00 of the Ian Darwin/Christos Zoulas implementation of <code>file</code>, the functionality of the command is implemented in and exposed by a <code>libmagic</code> [[library (computing)|library]] that is accessible to consuming code via [[C (programming language)|C]] (and compatible) linking.<ref>{{man|3|libmagic|Linux}}</ref><ref>{{man|3|libmagic|NetBSD}}</ref><ref>{{cite mailing list |url=https://mx.gw.com/pipermail/file/2003/000034.html |title=file-3.41 is now available |date=February 27, 2003 |access-date=January 1, 2013 |mailing-list=File |last=Zoulas |first=Christos |archive-date=March 4, 2016 |archive-url=https://web.archive.org/web/20160304040612/https://mx.gw.com/pipermail/file/2003/000034.html |url-status=live }}</ref><ref>{{cite mailing list |url=https://mx.gw.com/pipermail/file/2003/000043.html |title=file-4.00 is now available |date=March 24, 2003 |access-date=January 1, 2013 |mailing-list=File |last=Zoulas |first=Christos |archive-date=December 28, 2016 |archive-url=https://web.archive.org/web/20161228123411/https://mx.gw.com/pipermail/file/2003/000043.html |url-status=live }}</ref>