LN(1)                       General Commands Manual                      LN(1)

NAME
     ln, link – link files

SYNOPSIS
     ln [-L | -P | -s [-F]] [-f | -iw] [-hnv] source_file [target_file]
     ln [-L | -P | -s [-F]] [-f | -iw] [-hnv] source_file ... target_dir
     link source_file target_file

DESCRIPTION
     The ln utility creates a new directory entry (linked file) for the file
     name specified by target_file.  The target_file will be created with the
     same file modes as the source_file.  It is useful for maintaining
     multiple copies of a file in many places at once without using up storage
     for the “copies”; instead, a link “points” to the original copy.  There
     are two types of links; hard links and symbolic links.  How a link
     “points” to a file is one of the differences between a hard and symbolic
     link.

     The options are as follows:

     -F    If the target file already exists and is a directory, then remove
           it so that the link may occur.  The -F option should be used with
           either -f or -i options.  If neither -f nor -i is specified, -f is
           implied.  The -F option is a no-op unless -s is specified.

     -L    When creating a hard link to a symbolic link, create a hard link to
           the target of the symbolic link.  This is the default.  This option
           cancels the -P option.

     -P    When creating a hard link to a symbolic link, create a hard link to
           the symbolic link itself.  This option cancels the -L option.

     -f    If the target file already exists, then unlink it so that the link
           may occur.  (The -f option overrides any previous -i and -w
           options.)

     -h    If the target_file or target_dir is a symbolic link, do not follow
           it.  This is most useful with the -f option, to replace a symlink
           which may point to a directory.

     -i    Cause ln to write a prompt to standard error if the target file
           exists.  If the response from the standard input begins with the
           character ‘y’ or ‘Y’, then unlink the target file so that the link
           may occur.  Otherwise, do not attempt the link.  (The -i option
           overrides any previous -f options.)

     -n    Same as -h, for compatibility with other ln implementations.

     -s    Create a symbolic link.

     -v    Cause ln to be verbose, showing files as they are processed.

     -w    Warn if the source of a symbolic link does not currently exist.

     By default, ln makes hard links.  A hard link to a file is
     indistinguishable from the original directory entry; any changes to a
     file are effectively independent of the name used to reference the file.
     Directories may not be hardlinked, and hard links may not span file
     systems.

     A symbolic link contains the name of the file to which it is linked.  The
     referenced file is used when an open(2) operation is performed on the
     link.  A stat(2) on a symbolic link will return the linked-to file; an
     lstat(2) must be done to obtain information about the link.  The
     readlink(2) call may be used to read the contents of a symbolic link.
     Symbolic links may span file systems and may refer to directories.

     Given one or two arguments, ln creates a link to an existing file
     source_file.  If target_file is given, the link has that name;
     target_file may also be a directory in which to place the link; otherwise
     it is placed in the current directory.  If only the directory is
     specified, the link will be made to the last component of source_file.

     Given more than two arguments, ln makes links in target_dir to all the
     named source files.  The links made will have the same name as the files
     being linked to.

     When the utility is called as link, exactly two arguments must be
     supplied, neither of which may specify a directory.  No options may be
     supplied in this simple mode of operation, which performs a link(2)
     operation using the two passed arguments.

EXAMPLES
     Create a symbolic link named /home/src and point it to /usr/src:

           # ln -s /usr/src /home/src

     Hard link /usr/local/bin/fooprog to file /usr/local/bin/fooprog-1.0:

           # ln /usr/local/bin/fooprog-1.0 /usr/local/bin/fooprog

     As an exercise, try the following commands:

           # ls -i /bin/[
           11553 /bin/[
           # ls -i /bin/test
           11553 /bin/test

     Note that both files have the same inode; that is, /bin/[ is essentially
     an alias for the test(1) command.  This hard link exists so test(1) may
     be invoked from shell scripts, for example, using the if [ ] construct.

     In the next example, the second call to ln removes the original foo and
     creates a replacement pointing to baz:

           # mkdir bar baz
           # ln -s bar foo
           # ln -shf baz foo

     Without the -h option, this would instead leave foo pointing to bar and
     inside foo create a new symlink baz pointing to itself.  This results
     from directory-walking.

     An easy rule to remember is that the argument order for ln is the same as
     for cp(1): The first argument needs to exist, the second one is created.

COMPATIBILITY
     The -h, -i, -n, -v and -w options are non-standard and their use in
     scripts is not recommended.  They are provided solely for compatibility
     with other ln implementations.

     The -F option is a FreeBSD extension and should not be used in portable
     scripts.

SEE ALSO
     link(2), lstat(2), readlink(2), stat(2), symlink(2), symlink(7)

STANDARDS
     The ln utility conforms to IEEE Std 1003.2-1992 (“POSIX.2”).

     The simplified link command conforms to Version 2 of the Single UNIX
     Specification (“SUSv2”).

HISTORY
     An ln command appeared in Version 1 AT&T UNIX.

macOS 15.2                       May 10, 2021                       macOS 15.2