PHP命令执行不一样

So i am trying to run a command in windows from php. I have a php file that runs a program PDFtoPrinter

The php looks like

$output = shell_exec(‘C:\PDFtoPrinter\PDFtoPRINTER.exe C:\Wamp\www\upload\’.$file;
echo $output

so if i run

C:\PDFtoPrinter\PDFtoPRINTER.exe C:\Wamp\www\upload\file.pdf

in command prompt it works great and prints two sided

when it runs through the php file it prints two pages one sided each. Could this be a property issue?

It turns out I needed to have Apache to run as the same user I set the default printer settings in