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本文檔使用 php中文網手册 發布
(PHP 4, PHP 5, PHP 7)
link — 建立一个硬连接
$target
, string $link
)link() 建立一个硬连接。
target
要链接的目标。
link
链接的名称。
成功时返回 TRUE
, 或者在失败时返回 FALSE
。
Note: Windows下:该功能需要以 elevated 模式运行,或者关闭 UAC。
版本 | 说明 |
---|---|
5.3.0 | 该功能在 Windows 平台下开始有效(Vista、 Server 2008 或更高版本)。 |
Example #1 Creating a simple hard link
<?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 , $link );
?>
Note: 此函数不能作用于远程文件,被检查的文件必须是可通过服务器的文件系统访问的。
[#1] Anonymous [2009-10-16 01:54:56]
to clarify:
in unix/linux:
hardlinks (by this function) cannot go across different filesystems.
softlinks can point anywhere.
in linux, hardlinking to directory is not permited.
[#2] stephane AT baladeauboutdumonde DOT com [2007-08-06 11:45:07]
Make link recursively :
<?php
function makeRecusLink($orig, $dest)
{
if (is_dir($orig)) {
if (substr($orig, -1) != '/') {
$orig .= '/';
}
$handle = opendir($orig);
while (false !== ($file = readdir($handle))) {
if ($file != '.' && $file != '..') {
$path = $orig.$file;
if (is_file($path)) {
@link($path, $dest.'/'.$file);
} else if (is_dir($path)) {
@mkdir($dest.'/'.$file, 0755);
makeRecusLink($path, $dest.'/'.$file);
}
}
}
}
closedir($handle);
}
?>
[#3] Jasper Bekkers [2006-08-02 07:16:51]
For a backup utility I needed link-like functionality on a windows system. As it isn't availible on windows, i tried to do it myself with the help of some tools. All you need is junction.exe from sysinternals in your %PATH%.
<?php
if(!function_exists('link')){ // Assume a windows system
function link($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
[#4] Guilherme Garnier [2006-04-25 11:32:10]
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