Страницы справочника OS X

Эта страница руководства для  версии 10.9 Mac OS X

Читать страницы руководства

LN(1)                     BSD General Commands Manual                    LN(1)

NAME
     link, ln -- make links

SYNOPSIS
     ln [-Ffhinsv] source_file [target_file]
     ln [-Ffhinsv] source_file ... target_dir
     link source_file target_file

DESCRIPTION
     The ln utility creates a new directory entry (linked file) which has the same modes as the original
     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 none is specified, -f is implied.
           The -F option is a no-op unless -s option is specified.

     -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.

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

     -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.

     By default, ln makes hard links.  A hard link to a file is indistinguishable from the original direc-tory directory
     tory entry; any changes to a file are effectively independent of the name used to reference the file.
     Hard links may not normally refer to directories and 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 direc-tories. directories.
     tories.

     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; other-wise otherwise
     wise 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 spec-ify specify
     ify a directory.  No options may be supplied in this simple mode of operation, which performs a link(2)
     operation using the two passed arguments.

COMPATIBILITY
     The -h, -i, -n and -v 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 FreeBSD extention 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.

BSD                            February 14, 2006                           BSD