本地机器上的php.ini不允许更改值

i am trying to change the php.ini on my local (mac)

i had the following file

php.ini.default

so I copied it to create a php.ini

cp php.ini.default php.ini

I now have the desired php.ini, however I am not allowed to make changes.

  :w! = 
  W10: Warning: Changing a readonly file
  E45: 'readonly' option is set (add ! to override)
  "php.ini" E212: Can't open file for writing

I have also tried changing the chmod

chmod 777 php.ini 
chmod: Unable to change file mode on php.ini: Operation not permitted

Short of throwing my mac in the ocean and abandoning php entirely, how do i change php.ini values on a local machine.