Editing Ln (Unix) (section)

{{Short description|Shell command for creating a link file}}
{{Lowercase title}}
{{Infobox software
| name                   = ln
| logo                   = 
| screenshot             = Ln-example-command.gif
| screenshot size        = 
| caption                = Example usage of {{code|ln}} utility
| author                 = [[AT&T Bell Laboratories]]
| developer              = Various [[open-source software|open-source]] and [[commercial software|commercial]] developers
| released               = {{Start date and age|1971|11|3}}
| latest release version = 
| latest release date    = 
| operating system       = [[Unix]], [[Unix-like]], [[IBM i]]
| platform               = [[Cross-platform]]
| genre                  = [[Command (computing)|Command]]
| license                = [[coreutils]]: [[GPLv3+]]
| website                = 
}}
'''{{code|ln}}''' is a [[shell (computing)|shell]] [[command (computing)|command]] for creating a link file to an existing [[computer file|file]] or [[computer directory|directory]].<ref name=UNIXKP>{{cite book|last1=Kernighan|first1=Brian W.|last2=Pike|first2=Rob|title=The Unix programming environment.|date=1984|publisher=Prentice-Hall|location=Englewood Cliffs, N.J.|isbn=013937681X|page=[https://archive.org/details/unixprogramminge0000kern/page/59 59]|url-access=registration|url=https://archive.org/details/unixprogramminge0000kern/page/59}}</ref> By default, the command creates a [[hard link]], but with the {{code|-s}} [[Command-line interface|command line]] option, it creates a [[symbolic link]].<ref>{{cite web|title=ln - The Open Group Base Specifications Issue 7|url=http://pubs.opengroup.org/onlinepubs/9699919799/utilities/ln.html|website=pubs.opengroup.org|publisher=The IEEE and The Open Group|access-date=7 August 2015}}</ref> Most systems disallow a hard link to a directory since such links could disrupt the structure of a [[file system]] and interfere with the operation of other utilities.<ref>{{cite web|title=Why are hard links not allowed to directories in UNIX/Linux?|url=http://unix.stackexchange.com/questions/22394/why-hard-links-not-allowed-to-directories-in-unix-linux?rq=1|website=unix.stackexchange.com|access-date=7 August 2015}}</ref> The command can create a symbolic link to non-existent file.<ref name=GNULnman />

The command appeared in Issue 2 of the [[X/Open]] Portability Guidelines.<ref name=SUS/> The version in [[GNU Core Utilities]] was written by Mike Parker and David MacKenzie.<ref>{{man|1|ln|ManKier}}</ref>
The command is available in [[Windows]] via [[UnxUtils]]<ref>{{Cite web|url=http://unxutils.sourceforge.net/|title=Native Win32 ports of some GNU utilities|website=unxutils.sourceforge.net}}</ref> and has been ported to [[IBM i]].<ref>{{cite web |title=IBM System i Version 7.2 Programming Qshell |language=en |author=IBM |website=[[IBM]] |author-link=IBM |url=https://www.ibm.com/support/knowledgecenter/ssw_ibm_i_74/rzahz/rzahzpdf.pdf?view=kc |access-date=2020-09-05 }}</ref>