If the goal is to change only files that end with ".php" in the current directory and all subdirectories, then you'll need something else.
As Boby mentioned, the original command "chmod -R 644 *.php" will only chmod files in the current directory that end with ".php"
Boby's command will recursively chmod
any file beneath the specified directory (no matter what extension the file has).
The find command is probably the right tool for the job:
Code:
find /top/level/directory -type f -name "*.php" -exec chmod 644 {} \;
That will find every regular file that ends with ".php" in the /top/level/directory
and all subdirectories and it will execute "chmod 644 <found filename>" for each one.