@verb #3797:"c_tap" this none this rxdo #833
@program #3797:"c_tap" this none this
comm = caller
comm:isa($comm) || raise(E_PERM)
if (!comm:_get_active())
  this:chan_join("control", "silently", comm)
  comm:action("command")
else
  for chan in (this:ls_chan(comm))
    this:chan_part(chan, comm)
  endfor
endif
.