ubuntu Perl 版本自由切换

参考http://stackoverflow.com/questions/22934080/how-to-downgrade-to-perl-5-10-1

Perlbrew will allow you to install multiple versions of Perl as user installed Perls. 

安装perlbrew

apt-get install perlbrew

To install a particular version of Perl:

perlbrew install 5.10  # I'm installing Perl 5.10!

安装perl前需要建立文件夹:~/perl5/perlbrew/dists和:~/perl5/perlbrew/bulid

To switch from one version of Perl to another:

perlbrew use 5.10   # Use this version in the current shell

or 

perlbrew switch 5.10  # This is now your default version of Perl