发送多行linux到PHP exec（）

Question

I'm trying to process multiple unix calls with exec() but the first command seems to have no effect on the second:

exec('cd ../my/new/directory/');
echo exec('pwd')' //directory the PHP is in. not the new directory/

What's the deal here?

Answer 1

When you call PHP's exec(), PHP will fork a new process, and exec (Unix syscall) the cd command. The parent process (PHP) will then wait on the child process to complete.

Thus, the cd only takes effect in the child process. After cd returns, your parent process (PHP) is in the same state it was in before.