banning in one line command

[Miguel González]

Dear all,

  I have Varnish 4.1 and I´m trying to run in one single line command a
ban for a particular website. If I run this:

  root at myserver [~] # varnishadm -T :6082 -S /etc/varnish/secret

  varnish> ban req.http.host ~ www.myserver.com
  200

   I get the 200 code. However If I run it in a single line I get no 200
return code:

  root at myserver [~] # varnishadm -T :6082 -S /etc/varnish/secret 'ban
req.http.host ~ www.myserver.com'

  I get nothing. If I try double quotes I get the same...

  I googled around and I find people asking the same but no solutions.

  What am I doing wrong?

  Thanks!

  Miguel