Trying to delete a directory and his hidden files in linux with php -

from command line when use:

rm -fr /path/dir/{*,.??*} 

i can delete files in /path/dir including hidden files, when try make php code:

system('rm -fr /path/dir/{*,.??*}') nothing happens.

i can't find why doesn't works

finally this:

system('rm -fr /path/dir && mkdir /path/dir); 

i removed directory files , after created directory. , work done.