LN(1)LN(1)NAME
ln - make hard or symbolic links to files
SYNOPSIS
/usr/bin/ln [-fns] source_file [target]
/usr/bin/ln [-fns] source_file... target
/usr/xpg4/bin/ln [-fs] source_file [target]
/usr/xpg4/bin/ln [-fs] source_file... target
DESCRIPTION
In the first synopsis form, the ln utility creates a new directory
entry (link) for the file specified by source_file, at the destination
path specified by target. If target is not specified, the link is made
in the current directory. This first synopsis form is assumed when the
final operand does not name an existing directory; if more than two op‐
erands are specified and the final is not an existing directory, an
error will result.
In the second synopsis form, the ln utility creates a new directory
entry for each file specified by a source_file operand, at a destina‐
tion path in the existing directory named by target.
The ln utility may be used to create both hard links and symbolic
links. A hard link is a pointer to a file and is indistinguishable
from the original directory entry. Any changes to a file are effective
independent of the name used to reference the file. Hard links may not
span file systems and may not refer to directories.
ln by default creates hard links. source_file is linked to target. If
target is a directory, another file named source_file is created in
target and linked to the original source_file.
If target is an existing file and the -f option is not specified, ln
will write a diagnostic message to standard error, do nothing more with
the current source_file, and go on to any remaining source_files.
A symbolic link is an indirect pointer to a file; its directory entry
contains the name of the file to which it is linked. Symbolic links may
span file systems and may refer to directories.
File permissions for target may be different from those displayed with
an -l listing of the ls(1) command. To display the permissions of tar‐
get, use ls -lL. See stat(2) for more information.
/usr/bin/ln
If /usr/bin/ln determines that the mode of target forbids writing, it
prints the mode (see chmod(1)), asks for a response, and reads the
standard input for one line. If the response is affirmative, the link
occurs, if permissible. Otherwise, the command exits.
/usr/xpg4/bin/ln
When creating a hard link, and the source file is itself a symbolic
link, the target will be a hard link to the file referenced by the sym‐
bolic link, not to the symbolic link object itself (source_file).
OPTIONS
The following options are supported for both /usr/bin/ln and
/usr/xpg4/bin/ln:
-f
Links files without questioning the user, even if the mode of
target forbids writing. This is the default if the standard input
is not a terminal.
-s
Creates a symbolic link.
If the -s option is used with two arguments, target may be an
existing directory or a non-existent file. If target already
exists and is not a directory, an error is returned. source_file
may be any path name and need not exist. If it exists, it may be
a file or directory and may reside on a different file system
from target. If target is an existing directory, a file is cre‐
ated in directory target whose name is source_file or the last
component of source_file. This file is a symbolic link that ref‐
erences source_file. If target does not exist, a file with name
target is created and it is a symbolic link that references
source_file.
If the -s option is used with more than two arguments, target
must be an existing directory or an error will be returned. For
each source_file, a link is created in target whose name is the
last component of source_file. Each new source_file is a symbolic
link to the original source_file. The files and target may reside
on different file systems.
/usr/bin/ln
The following option is supported for /usr/bin/ln only:
-n
If target is an existing file, writes a diagnostic message to
stderr and goes on to any remaining source_files. The -f option
overrides this option. This is the default behavior for
/usr/bin/ln and /usr/xpg4/bin/ln, and is silently ignored.
OPERANDS
The following operands are supported:
source_file
A path name of a file to be linked. This can be either a
regular or special file. If the -s option is specified,
source_file can also be a directory.
target
The path name of the new directory entry to be created,
or of an existing directory in which the new directory
entries are to be created.
USAGE
See largefile(5) for the description of the behavior of ln when encoun‐
tering files greater than or equal to 2 Gbyte ( 2^31 bytes).
ENVIRONMENT VARIABLES
See environ(5) for descriptions of the following environment variables
that affect the execution of ln: LANG, LC_ALL, LC_CTYPE, LC_MESSAGES,
and NLSPATH.
EXIT STATUS
The following exit values are returned:
0
All the specified files were linked successfully
>0
An error occurred.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
/usr/bin/ln
┌───────────────┬─────────────────┐
│ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├───────────────┼─────────────────┤
│CSI │ Enabled │
└───────────────┴─────────────────┘
/usr/xpg4/bin/ln
┌────────────────────┬─────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├────────────────────┼─────────────────┤
│CSI │ Enabled │
├────────────────────┼─────────────────┤
│Interface Stability │ Standard │
└────────────────────┴─────────────────┘
SEE ALSOchmod(1), ls(1), stat(2), attributes(5), environ(5), largefile(5),
standards(5)NOTES
A symbolic link to a directory behaves differently than you might
expect in certain cases. While an ls(1) command on such a link displays
the files in the pointed-to directory, entering ls -l displays informa‐
tion about the link itself:
example% ln -s dir link
example% ls link
file1 file2 file3 file4
example% ls -l link
lrwxrwxrwx 1 user 7 Jan 11 23:27 link -> dir
When you change to a directory (see cd(1)) through a symbolic link,
using /usr/bin/sh or /usr/bin/csh, you wind up in the pointed-to loca‐
tion within the file system. This means that the parent of the new
working directory is not the parent of the symbolic link, but rather,
the parent of the pointed-to directory. This will also happen when
using cd with the -P option from /usr/bin/ksh or /usr/xpg4/bin/sh. For
instance, in the following case, the final working directory is /usr
and not /home/user/linktest.
example% pwd
/home/user/linktest
example% ln -s /usr/tmp symlink
example% cd symlink
example% cd ..
example% pwd
/usr
C shell users can avoid any resulting navigation problems by using the
pushd and popd built-in commands instead of cd.
Mar 25, 2004 LN(1)
