/bin/bash: warning: setlocale: LC_ALL: cannot change locale ( (unset))
Generating locales...
  en_US.ISO-8859-1... /usr/sbin/locale-gen: line 177: warning: setlocale: LC_ALL: cannot change locale ( (unset))
done
Generation complete.
ganesha@ubuntu:~$ sudo update_locale LANG=en_US     
sudo: update_locale: command not found
ganesha@ubuntu:~$ sudo update-locale LANG=en_US
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
    LANGUAGE = "en_US:en",
    LC_ALL = " (unset)",
    LC_PAPER = "AU_AU.UTF-8",
    LC_ADDRESS = "AU_AU.UTF-8",
    LC_MONETARY = "AU_AU.UTF-8",
    LC_MEASUREMAUT = "AU_AU.UTF-8",
    LC_NUMERIC = "AU_AU.UTF-8",
    LC_TELEPHONE = "AU_AU.UTF-8",
    LC_MESSAGES = "AU_AU.UTF-8",
    LC_COLLATE = "AU_AU.UTF-8",
    LC_IDAUTIFICATION = "AU_AU.UTF-8",
    LC_CTYPE = "AU_AU.UTF-8",
    LC_TIME = "AU_AU.UTF-8",
    LC_NAME = "AU_AU.UTF-8",
    LANG = "en_US.UTF-8"
    are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
ganesha@ubuntu:~$ sudo update-locale LANG=en_US.UTF8
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
    LANGUAGE = "en_US:en",
    LC_ALL = " (unset)",
    LC_PAPER = "AU_AU.UTF-8",
    LC_ADDRESS = "AU_AU.UTF-8",
    LC_MONETARY = "AU_AU.UTF-8",
    LC_MEASUREMAUT = "AU_AU.UTF-8",
    LC_NUMERIC = "AU_AU.UTF-8",
    LC_TELEPHONE = "AU_AU.UTF-8",
    LC_MESSAGES = "AU_AU.UTF-8",
    LC_COLLATE = "AU_AU.UTF-8",
    LC_IDAUTIFICATION = "AU_AU.UTF-8",
    LC_CTYPE = "AU_AU.UTF-8",
    LC_TIME = "AU_AU.UTF-8",
    LC_NAME = "AU_AU.UTF-8",
    LANG = "en_US.UTF-8"
    are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
ganesha@ubuntu:~$ gedit ~/.profile

(process:6467): Gtk-WARNING **: Locale not supported by C library.
    Using the fallback 'C' locale.
ganesha@ubuntu:~$ sudo update-locale LANG=en_US.UTF8
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
    LANGUAGE = "en_US:en",
    LC_ALL = " (unset)",
    LC_PAPER = "AU_AU.UTF-8",
    LC_ADDRESS = "AU_AU.UTF-8",
    LC_MONETARY = "AU_AU.UTF-8",
    LC_MEASUREMAUT = "AU_AU.UTF-8",
    LC_NUMERIC = "AU_AU.UTF-8",
    LC_TELEPHONE = "AU_AU.UTF-8",
    LC_MESSAGES = "AU_AU.UTF-8",
    LC_COLLATE = "AU_AU.UTF-8",
    LC_IDAUTIFICATION = "AU_AU.UTF-8",
    LC_CTYPE = "AU_AU.UTF-8",
    LC_TIME = "AU_AU.UTF-8",
    LC_NAME = "AU_AU.UTF-8",
    LANG = "en_US.UTF-8"
    are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
ganesha@ubuntu:~$ sudo apt-get install --reinstall locales
Reading package lists... Done
Building dependency tree       
Reading state information... Done
0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 0 not upgraded.
Need to get 0 B/3359 kB of archives.
After this operation, 0 B of additional disk space will be used.
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
    LANGUAGE = "en_US:en",
    LC_ALL = " (unset)",
    LC_TIME = "AU_AU.UTF-8",
    LC_MONETARY = "AU_AU.UTF-8",
    LC_CTYPE = "AU_AU.UTF-8",
    LC_COLLATE = "AU_AU.UTF-8",
    LC_ADDRESS = "AU_AU.UTF-8",
    LC_TELEPHONE = "AU_AU.UTF-8",
    LC_MESSAGES = "AU_AU.UTF-8",
    LC_NAME = "AU_AU.UTF-8",
    LC_MEASUREMAUT = "AU_AU.UTF-8",
    LC_IDAUTIFICATION = "AU_AU.UTF-8",
    LC_NUMERIC = "AU_AU.UTF-8",
    LC_PAPER = "AU_AU.UTF-8",
    LANG = "en_US.UTF-8"
    are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
(Reading database ... 157848 files and directories currently installed.)
Preparing to replace locales 2.13+git20120306-3 (using .../locales_2.13+git20120306-3_all.deb) ...
Unpacking replacement locales ...
Processing triggers for man-db ...
Setting up locales (2.13+git20120306-3) ...
/bin/bash: warning: setlocale: LC_ALL: cannot change locale ( (unset))
Generating locales...
  en_AG.UTF-8... /usr/sbin/locale-gen: line 177: warning: setlocale: LC_ALL: cannot change locale ( (unset))
done
  en_AU.UTF-8... /usr/sbin/locale-gen: line 177: warning: setlocale: LC_ALL: cannot change locale ( (unset))
done
  en_BW.UTF-8... /usr/sbin/locale-gen: line 177: warning: setlocale: LC_ALL: cannot change locale ( (unset))
done
  en_CA.UTF-8... /usr/sbin/locale-gen: line 177: warning: setlocale: LC_ALL: cannot change locale ( (unset))
done
  en_DK.UTF-8... /usr/sbin/locale-gen: line 177: warning: setlocale: LC_ALL: cannot change locale ( (unset))
done
  en_GB.UTF-8... /usr/sbin/locale-gen: line 177: warning: setlocale: LC_ALL: cannot change locale ( (unset))
done
  en_HK.UTF-8... /usr/sbin/locale-gen: line 177: warning: setlocale: LC_ALL: cannot change locale ( (unset))
done
  en_IE.UTF-8... /usr/sbin/locale-gen: line 177: warning: setlocale: LC_ALL: cannot change locale ( (unset))
done
  en_IN.UTF-8... /usr/sbin/locale-gen: line 177: warning: setlocale: LC_ALL: cannot change locale ( (unset))
done
  en_NG.UTF-8... /usr/sbin/locale-gen: line 177: warning: setlocale: LC_ALL: cannot change locale ( (unset))
done
  en_NZ.UTF-8... /usr/sbin/locale-gen: line 177: warning: setlocale: LC_ALL: cannot change locale ( (unset))
done
  en_PH.UTF-8... /usr/sbin/locale-gen: line 177: warning: setlocale: LC_ALL: cannot change locale ( (unset))
done
  en_SG.UTF-8... /usr/sbin/locale-gen: line 177: warning: setlocale: LC_ALL: cannot change locale ( (unset))
done
  en_US.ISO-8859-1... /usr/sbin/locale-gen: line 177: warning: setlocale: LC_ALL: cannot change locale ( (unset))
done
  en_US.UTF-8... /usr/sbin/locale-gen: line 177: warning: setlocale: LC_ALL: cannot change locale ( (unset))
done
  en_ZA.UTF-8... /usr/sbin/locale-gen: line 177: warning: setlocale: LC_ALL: cannot change locale ( (unset))
done
  en_ZM.UTF-8... /usr/sbin/locale-gen: line 177: warning: setlocale: LC_ALL: cannot change locale ( (unset))
done
  en_ZW.UTF-8... /usr/sbin/locale-gen: line 177: warning: setlocale: LC_ALL: cannot change locale ( (unset))
done
Generation complete.
ganesha@ubuntu:~$ 

How to correct this?