有没有办法制作一个无法转换成单词的pdf？

Question

We have a system which is generating PDF files. But anyone can convert those files using online pdf to word converter. Is there any option available in Yii or PHP to stop this?

Answer 1

To disable converting PDF in any other format you can use for example PDFTK command line, you can find it here
It will prompt a password when user try to print your PDF document (consider converting format is also a printing mechanism)

command line

pdftk source.pdf output destination.pdf user_pw password

So to use it in PHP do not forget to add PDFTK to your PATH environment variable, set access authorizations and restart your web server

EDIT you can use shell_exec()

<?php
// ... 
shell_exec('pdftk source.pdf output destination.pdf user_pw password');
?>