使用php将文件添加到rar存档

is it at all possible to add files to a RAR archive using PHP? After doing some research I'm lead to believe you can only decompress rar files due to licensing issues. I'm only asking as installing the zip module is out of the question because the server I'm maintaining has 50+ accounts on there and updating PHP will cause a lot of them to break.

No, it is not possible to add files to a RAR archive by plain standard PHP. You are only able to extract them. Anyways, there is a RAR program, which is the only allowed way to add files to a RAR archive. You can access this RAR program by using PHP exec(). It can even use passwords for archives.

Check it out here:

http://www.phpclasses.org/package/3556-PHP-Pack-files-in-compressed-RAR-archives.html

If the command line RAR tools are on the host, you can use them with PHP via exec() etc.

Here's an example on a Windows host from http://www.php.net/manual/en/rar.examples.php#100963

<?php
function RARFiles($Output='output.rar',$Files=array()) {
  $Data='';
  for($i=0;$i<count($Files);$i++)
    $Data.="\"{$Files[$i]}\" ";
  exec("rar.exe a \"{$Output}\" {$Data}");
}

$Files=array('file1.ext','file2.ext','file3.ext');
RARFiles('asdf.rar',$Files);
// asdf.rar created.
?>

From what I can tell, it's not possible to create RAR archives in PHP due to licensing as you said. But you can work with existing archives to a degree with http://php.net/manual/en/book.rar.php.