Logstash parsing syslog

Thank you magnus.

Is it possible to reuse the name of the syslog directory for the "host" field Logstash ?
For example, use the $HOST for the host field.

input {
file {
path => ["path/to/$HOST/file.log"]
start_position => "beginning"
type => "linux-syslog"
ignore_older => 0
}
}