MacOS------>>brew Update Error

When installing cocoapods, you need to upgrade the version of Ruby <= 2.2.0 and then upgrade Ruby to update HomeBrew directly performing brew update will explode the following error

#$ Brew Update

Error:/usr/local is not writable. You should the ownership

and permissions of/usr/local your user account:

sudo chown-r $ (whoami)/usr/local

macosdemacbook-pro:~ macos$ sudo chown-r/usr/local

Usage:chown [-FHV] [-R [-H |-l |-p]] owner[:group] File ...

chown [-FHV] [-R [-H |-l |-p]]: Group file ...

Reason:

Brew Update does not have permission to modify this directory for '/usr/local '

Solution:

Using the SU user update

sudo brew update

MacOS------>>brew Update Error