不管别人怎么说，反正我是非常喜欢perl语言的！
也会继续学习，以前写过不少perl模块的博客，发现有点乱，正好最近看到了关于local::lib这个模块。
居然是用来解决没有root权限的用户安装，perl模块问题的！
首先说一下，如果是root用户，模块其实没有问题，直接用cpan下载器，几乎能解决所有的模块下载安装问题！
但是如果是非root用户，那么就麻烦了，很难用自动的cpan下载器，这样只能下载模块源码，然后编译，但是编译有个问题，很多模块居然是依赖于其它模块的，你的不停地下载其它依赖模块，最后才能解决，特别麻烦
但是，只需要运行下面的代码：
wget -O- http://cpanmin.us | perl - -l ~/perl5 App::cpanminus local::lib
eval `perl -I ~/perl5/lib/perl5 -Mlocal::lib`
echo 'eval `perl -I ~/perl5/lib/perl5 -Mlocal::lib`' >> ~/.profile
echo 'export MANPATH=$HOME/perl5/man:$MANPATH' >> ~/.profile
就能拥有一个私人的cpan下载器，~/.profile可能需要更改为.bash_profile, .bashrc, etc等等，取决于你的linux系统！
然后你直接运行cpanm Module::Name，就跟root用户一样的可以下载模块啦！
或者用下面的方式在shell里面安装模块，其中ext是模块的安装目录，可以修改
perl -MTime::HiRes -e 1 > /dev/null 2>&1 || cpanm -v --notest -l ext Time::HiRes;
perl -MFile::Path -e 1 > /dev/null 2>&1 || cpanm -v --notest -l ext File::Path;
perl -MFile::Basename -e 1 > /dev/null 2>&1 || cpanm -v --notest -l ext File::Basename;
perl -MFile::Copy -e 1 > /dev/null 2>&1 || cpanm -v --notest -l ext File::Copy;
perl -MIO::Handle -e 1 > /dev/null 2>&1 || cpanm -v --notest -l ext IO::Handle;
perl -MYAML::XS -e 1 > /dev/null 2>&1 || cpanm -v --notest -l ext YAML::XS;
perl -MYAML -e 1 > /dev/null 2>&1 || cpanm -v --notest -l ext YAML;
perl -MXML::Simple -e 1 > /dev/null 2>&1 || cpanm -v --notest -l ext XML::Simple;
perl -MStorable -e 1 > /dev/null 2>&1 || cpanm -v --notest -l ext Storable;
perl -MStatistics::Descriptive -e 1 > /dev/null 2>&1 || cpanm -v --notest -l ext Statistics::Descriptive;
perl -MTie::IxHash -e 1 > /dev/null 2>&1 || cpanm -v --notest -l ext Tie::IxHash;
perl -MAlgorithm::Combinatorics -e 1 > /dev/null 2>&1 || cpanm -v --notest -l ext Algorithm::Combinatorics;
perl -MDevel::Size -e 1 > /dev/null 2>&1 || cpanm -v --notest -l ext Devel::Size;
perl -MSort::Key::Radix -e 1 > /dev/null 2>&1 || cpanm -v --notest -l ext Sort::Key::Radix;
perl -MSort::Key -e 1 > /dev/null 2>&1 || cpanm -v --notest -l ext Sort::Key;
perl -MBit::Vector -e 1 > /dev/null 2>&1 || cpanm -v --notest -l ext Bit::Vector;
perl -M"feature 'switch'" -e 1 > /dev/null 2>&1 || cpanm -v --notest -l ext feature;
下面是解释为什么这样可以解决问题！！！
What follows is a brief explanation of what the commands above do.
wget -O- http://cpanmin.us fetches the latest version of cpanm and prints it to STDOUT which is then piped to perl - -l ~/perl5 App::cpanminus local::lib. The first - tells perl to expect the program to come in on STDIN, this makes perl run the version of cpanm we just downloaded.perl passes the rest of the arguments to cpanm. The -l ~/perl5 argument tells cpanm where to install Perl modules, and the other two arguments are two modules to install. [App::cpanmins]1 is the package that installs cpanm. local::lib is a helper module that manages the environment variables needed to run modules in local directory.
After those modules are installed we run
eval `perl -I ~/perl5/lib/perl5 -Mlocal::lib`
to set the environment variables needed to use the local modules and then
echo 'eval `perl -I ~/perl5/lib/perl5 -Mlocal::lib`' >> ~/.profile
to ensure we will be able to use them the next time we log in.
echo 'export MANPATH=$HOME/perl5/man:$MANPATH' >> ~/.profile
will hopefully cause man to find the man pages for your local modules.
这种类似的问题被问的特别多！
There's the way documented in perlfaq8, which is what local::lib is doing for you.
It's also a frequently asked StackOverflow question:
