LN(1) User Commands 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...
targetDESCRIPTION
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 operands
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 destination 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
target,
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 symbolic
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 created in directory
target whose name is
source_file or the last component of
source_file. This file is a symbolic link that references
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(7) for the description of the behavior of
ln when
encountering files greater than or equal to 2 Gbyte ( 2^31 bytes).
ENVIRONMENT VARIABLES
See
environ(7) 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(7) 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 ALSO
chmod(1),
ls(1),
stat(2),
attributes(7),
environ(7),
largefile(7),
standards(7)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 information
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 location
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.
March 25, 2004
LN(1)