Jenkins groovy script; run command on each slave

script.groovy

// Run from https://jenkins/script

import hudson.util.RemotingDiagnostics;

cmd = 'def proc = ["conan", "--version"].execute(); proc.waitFor(); println proc.in.text';

for (slave in hudson.model.Hudson.instance.slaves) {
  if (slave.name ==~ /^build-slave[0-9]/) {
    println slave.name;
    println RemotingDiagnostics.executeGroovy(cmd, slave.getChannel());
  }
}

Delete folders:

println new File("c:\\path").deleteDir()