perl: warning: Please check that your locale settings ubuntu

This actually a pretty simple error that you'll encounter if there is a problem with your locale setting in Ubuntu (or maybe other Linux distro). Yet, it'll make you annoy to the max if you don't fix it.

perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LANGUAGE = “en_US.UTF-8″,
LC_ALL = “en_US.UTF-8″,
LANG = “en_US.UTF-8″
are supported and installed on your system.
perl: warning: Falling back to the standard locale (“C”).
locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_MESSAGES to default locale: No such file or directory

locale: Cannot set LC_ALL to default locale: No such file or directory

  
This post is actually for my reference in the future if I encounter such problem again. The problem with me is that, I found a lot of same solution for this error, but all of it don't really shut that error message. The only one that works is below command:

$ export LANGUAGE=en_US.UTF-8
$ export LANG=en_US.UTF-8
$ export LC_ALL=en_US.UTF-8
$ locale-gen en_US.UTF-8
$ sudo dpkg-reconfigure locales

Credit: Hone Watson