You can also use environment variables in "epools.txt" and "config.txt" files. For example, define "WORKER" environment variable and use it as "%WORKER%" in config.txt or in epools.txt.
On Ubuntu (switching because of 1050ti problem) I have environment variable $HOSTNAME:
> echo $HOSTNAME
Farm9
As said in readme, I specify it in config.txt %HOSTNAME% as my worker but it do not work.