If you missed that argument when initially installing php5 and want to add it after the fact, this is all you need:
sudo apt-get install php5-readline
要使用这些函数，你必须在编译 PHP 的 CGI 或者 CLI 版本时启用 readline 支持. 你需要在编译配置 PHP 时使用 --with-readline[=DIR] 选项. 如果你想使用 libedit 来代替 readline , 配置 PHP 时使用 --with-libedit[=DIR] 选项
If you missed that argument when initially installing php5 and want to add it after the fact, this is all you need:
sudo apt-get install php5-readline
Use dotdeb. It's like 1 minute work.
Follow https://www.dotdeb.org/instructions/
Do only points 1,3,4 (omit 2)
and then
sudo apt-get install php5-readline