Is it possible to set variables in file path?

I have a directory contains too many logs which were named as log-YYYYMMDD ranging from 5 years ago to now.

I do not want Logstash to parse the old logs. So I need something like this

input {
  file {
    param => { "today" => "" }
    path => "/path/to/log-{%today}"

Or any other ideas to solve this problem?
Thank you for your help.

Use the file input's ignore_older option to ignore old files.