@verb #3797:"chan_send" this none this rxdo #833
@program #3797:"chan_send" this none this
$perm_utils:can_hack() || raise(E_PERM)
{id, comm, text} = args
"First, pre-transmission processing, channel history updates, etc.:"
{members, history, atime, @options} = this:get_chan(id)
if ("/dev/null" in options)
  return
endif
sig = string_hash(text)
if (valid(comm))
  if (!comm in members)
    return
  endif
  locations = {}
  for c in (members)
    locations = {@locations, c:where()}
  endfor
  loc = locations[comm in members]
  "Echo supression, part 1"
  for h in (history)
    {which, where, what} = h
    if (which != comm && where == loc && what == sig)
      "Already heard this message"
      return
    endif
  endfor
else
  loc = #-1
endif
history = {{comm, loc, sig}, @history[1..min($, this.echo_hist_max)]}
this:set_chan(id, {members, history, time(), @options})
"Begin to transmit"
done = {loc}
for i in [1..length(members)]
  "Echo supression, part 2"
  l = locations[i]
  c = members[i]
  if (!(l in done))
    done = {@done, l}
    c:do_announce(text)
  endif
  $command_utils:suspend_if_needed()
endfor
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