exec命令在php中不起作用，但是在终端/ putty中起作用

Question

I am trying to run convert 'sample_(2).pdf[1]' 'sample.jpg' through php exec like below

> exec(" convert 'sample_(2).pdf[1]' 'sample.jpg' ");

But it is not working in php but works great in terminal. I tried below codes also to check wethee exec is working with php.

echo exec('whoami'); //It is working and giving me result

exec("cp 'sample_(2).pdf' sample2.pdf");

//It is not working.

But all the commands are running in terminal. Any idea would help me. I am scratching my head for the last two days.

EDIT

I got it working. There were mistakes with my file path.

Answer 1

I guess that the web server does not have permission to write to the folder you want to write. Check the folder permissions for your webserver (probably "www-data").