The link() creates a hard link for a specified target. The target and the link are passed as parameters to the link() function and it returns true on success and false on failure.
Syntax: 

link(target, link)

Parameters Used: 
The link() function in PHP accepts two parameters. 

1. target : It is a mandatory parameter which specifies the target.
2. link : It is an mandatory parameter which specifies the name of the link.

Return Value: 
It returns TRUE on success or FALSE on failure.

Errors And Exception 

1. The link() function does not work on remote files as the file to be examined must be accessible via the server's filesystem.
2. The link created by the link() function is not an HTML link, but a link in the filesystem..
3. In linux, hardlinking to a directory is not permitted.

Examples: 

Input : $targetfile = 'gfg.txt.'; 
        $linkname = 'gfglink';
        link($targetfile, $linkname);
Output : 1

Input : $targetfile = 'gfg.txt.'; 
        $linkname = 'gfglink';

        if(!link($targetfile, $linkname))
        {
           echo('Link has been created!');
        }
        else
        {
          echo('Link cannot be created!');
        }
Output : Link has been created!

Below programs illustrate the link() function.
Program 1

<?php 
// target file
$targetfile = 'gfg.txt'; 

// name of the link
$linkname = 'gfglink';

// creating a symbolic link for the target file
link($targetfile, $linkname);
?>

Output: 

1

Program 2

<?php 

// target file
$targetfile = 'gfg.txt'; 

// name of the link
$linkname = 'gfglink';

// creating a symbolic link for the target file
if(!link($targetfile, $linkname))
 { 
    echo('Link has been created!');
 }
else
 {
    echo('Link cannot be created!');
 }
?>

Output: 

Link has been created!

Related Article: PHP | symlink( ) function
Reference: 
http://php.net/manual/en/function.link.php