perl: warning: Setting locale fa

在第一次登录系统会出现报错：perl: warning: Setting locale failed.

root@linyk3:~# adduser linyk3
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
    LANGUAGE = (unset),
    LC_ALL = (unset),
    LC_PAPER = "zh_CN.UTF-8",
    LC_ADDRESS = "zh_CN.UTF-8",
    LC_MONETARY = "zh_CN.UTF-8",
    LC_NUMERIC = "zh_CN.UTF-8",
    LC_TELEPHONE = "zh_CN.UTF-8",
    LC_IDENTIFICATION = "zh_CN.UTF-8",
    LC_MEASUREMENT = "zh_CN.UTF-8",
    LC_TIME = "zh_CN.UTF-8",
    LC_NAME = "zh_CN.UTF-8",
    LANG = "en_US.UTF-8"
    are supported and installed on your system.
perl: warning: Falling back to a fallback locale ("en_US.UTF-8").
root@linyk3:~# 

经过网上查询perl: warning: Setting locale failed.引发的问题
那是因为安装软件时，都会去执行一个update-locale的命令，用来更新locale
这个命令是一个脚本，用perl写的，可以用whereis update-locale查到，位置在/usr/sbin/update-locale
其实，真正的原因是perl为系统使用zh_CN.UTF-8，但系统不知道zh_CN.UTF-8是什么东西
所以安装一个中文语言，系统就知道zh_CN.UTF-8了，这个时候用perl就不会报错了

apt-get install language-pack-zh-hans

但是在执行过程中报错:

root@linyk3:~# apt-get install language-pack-zh-hans
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package language-pack-zh-hans
root@linyk3:~# apt-get install language-pack-zh-hans
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package language-pack-zh-hans
root@linyk3:~# 

应该是没有更新，所以执行下:

apt-get update

更新结束后再安装中文包就可以了。

root@linyk3:~# apt-get install language-pack-zh-hans
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages were automatically installed and are no longer required:
  linux-headers-4.4.0-87 linux-headers-4.4.0-87-generic linux-image-4.4.0-87-generic linux-image-extra-4.4.0-87-generic
Use 'apt autoremove' to remove them.
The following additional packages will be installed:
  language-pack-zh-hans-base
The following NEW packages will be installed:
  language-pack-zh-hans language-pack-zh-hans-base
0 upgraded, 2 newly installed, 0 to remove and 162 not upgraded.
Need to get 2110 kB of archives.
After this operation, 8545 kB of additional disk space will be used.
Do you want to continue? [Y/n]