to clarify:
in unix/linux:
hardlinks (by this function) cannot go across different filesystems.
softlinks can point anywhere.
in linux, hardlinking to directory is not permited.
link
(PHP 4, PHP 5, PHP 7, PHP 8)
link — 建立一个硬连接
参数
-
target -
要链接的目标。
-
link -
链接的名称。
返回值
成功时返回 true， 或者在失败时返回 false。
错误／异常
如果 link 已存在或者 target
不存在，此函数会失败并发出 E_WARNING。
示例
示例 #1 创建简单的硬链接
<?php
$target = 'source.ext'; // This is the file that already exists
$link = 'newfile.ext'; // This the filename that you want to link it to
link($target, $link);
?>
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User Contributed Notes 4 notes
Anonymous ¶
15 years ago
Jasper Bekkers ¶
18 years ago
For a backup utility I needed link-like functionality on a windows system. As it isn't availible on windows, i tried to do it myself with the help of some tools. All you need is junction.exe from sysinternals in your %PATH%.
<?php
if(!function_exists('link')){ // Assume a windows system
function link($target, $link){
if(is_dir($target)){
// junctions link to directories in windows
exec("junction $link $target", $lines, $val);
return 0 == $val;
}elseif(is_file($target)){
// Hardlinks link to files in windows
exec("fsutil hardlink create $link $target", $lines, $val);
return 0 == $val;
}
return false;
}
}
?>
http://www.sysinternals.com/Utilities/Junction.html
Guilherme Garnier ¶
18 years ago
I noticed that, differently from Unix ln command, the second parameter can´t be a directory name, i.e., if you want to create a link with the same filename of the target file (obviously on different directories), you must specify the filename on the link parameter.
Example:
Unix ln command:
ln /dir1/file /dir2/ // ok, creates /dir2/file link
PHP link function:
link ("/dir1/file", "/dir2/"); // wrong, gives a "File exists" warning
link ("/dir1/file", "/dir2/file"); // ok, creates /dir2/file link
crashulater at virtualcrash dot com ¶
6 years ago
In at least php-5.3 (linux-2.6.38.6) a process owned by apache could make a link() in a directory owned by apache, to a file owned by webmaster to which it had group read permissions. In php-7.0 (linux-4.13.16) that results in a "permission denied". Either the target file must be owned by apache or one must use copy() instead (so that ownership changes to apache).
