The Single UNIX ® Specification, Version 2
Copyright © 1997 The Open Group

 NAME

ln - link files

 SYNOPSIS



ln [-f] source_file target_file

ln [-f] source_file... target_dir

 DESCRIPTION

In the first synopsis form, the ln utility will create a new directory entry (link) for the file specified by the source_file operand, at the destination path specified by the target_file operand. 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 will create a new directory entry for each file specified by a source_file operand, at a destination path in the existing directory named by target_dir.

If the last operand specifies an existing file of a type not specified by the XSH specification, the behaviour is implementation-dependent.

The corresponding destination path for each source_file will be the concatenation of the target directory pathname, a slash character, and the last pathname component of the source_file. The second synopsis form will be assumed when the final operand names an existing directory.

For each source_file:

  1. If the destination path exists:

    1. If 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.

    2. Actions will be performed equivalent to the XSH specification unlink() function, called using destination as the path argument. If this fails for any reason, 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.

  2. Actions will be performed equivalent to the XSH specification link() function using source_file as the path1 argument, and the destination path as the path2 argument.

 OPTIONS

The ln utility supports the XBD specification, Utility Syntax Guidelines  .

The following option is supported:

-f
Force existing destination pathnames to be removed to allow the link.

 OPERANDS

The following operands are supported:
source_file
A pathname of a file to be linked. This can be a regular or special file; whether a directory can be linked is implementation-dependent.
target_file
The pathname of the new directory entry to be created.
target_dir
A pathname of an existing directory in which the new directory entries are to be created.

 STDIN

Not used.

 INPUT FILES

None.

 ENVIRONMENT VARIABLES

The following environment variables affect the execution of ln:
LANG
Provide a default value for the internationalisation variables that are unset or null. If LANG is unset or null, the corresponding value from the implementation-dependent default locale will be used. If any of the internationalisation variables contains an invalid setting, the utility will behave as if none of the variables had been defined.
LC_ALL
If set to a non-empty string value, override the values of all the other internationalisation variables.
LC_CTYPE
Determine the locale for the interpretation of sequences of bytes of text data as characters (for example, single- as opposed to multi-byte characters in arguments).
LC_MESSAGES
Determine the locale that should be used to affect the format and contents of diagnostic messages written to standard error.
NLSPATH
Determine the location of message catalogues for the processing of LC_MESSAGES .

 ASYNCHRONOUS EVENTS

Default.

 STDOUT

Not used.

 STDERR

Used only for diagnostic messages.

 OUTPUT FILES

None.

 EXTENDED DESCRIPTION

None.

 EXIT STATUS

The following exit values are returned:
0
All the specified files were linked successfully.
>0
An error occurred.

 CONSEQUENCES OF ERRORS

Default.

 APPLICATION USAGE

None.

 EXAMPLES

None.

 FUTURE DIRECTIONS

None.

 SEE ALSO

chmod, find, pax, rm.

UNIX ® is a registered Trademark of The Open Group.
Copyright © 1997 The Open Group
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