On Ubuntu 13.10 can`t install Composer

[jakubzapletal]

In running script plugins/php5/script/php.sh I got error:

#!/usr/bin/env php
Some settings on your machine make Composer unable to work properly.
Make sure that you fix the issues listed below and run this script again:

The json extension is missing.
Install it or recompile php without --disable-json

It can be done, if you set apt-get install php5-json

[mhlavac]

Thank you for reporting that. I'll get it fixed