# 1

I found this one at [this reddit](https://www.reddit.com/r/Reaper/comments/pjttl2/i_created_a_new_script_that_will_route_all/)

There were some comments (copied below) on how it could be improved.
One addition I make (mentioned below) is to default the send to `-∞ dB`,
rather than the `0dB` that is the default for sends (and I don't want to
change that default since it's good for other sends).
```lua
local tr_cnt = reaper.CountSelectedTracks( 0 )
local fnd = 0
local sel_tr = {}
local store = {}

  -- add channel selector
  reaper.Undo_BeginBlock2( 0 )
  reaper.PreventUIRefresh( 1 )
  for i = 0, tr_cnt-1 do
    sel_tr[#sel_tr+1] = reaper.GetSelectedTrack( 0, i )
  end
  
  -- Finding track named Reverb
  for trackIndex = 0, reaper.CountTracks(0) - 1 do
    local tr = reaper.GetTrack(0, trackIndex)
    local _, trackName = reaper.GetSetMediaTrackInfo_String(tr, 'P_NAME', '', false)
    if string.match(trackName, "Reverb") ~= nil then -- Change Reverb for any other string you like
      store[#store+1] = tr
      fnd = fnd+1
    end
  end  
  if fnd == 0 then
    reaper.ShowMessageBox("No tracks with the name Reverb found!", "Error!", 0)
  end
  
  if fnd == 1 then
    for i = 1, #sel_tr do
      reaper.CreateTrackSend( sel_tr[i], store[fnd] )
    end
  end
  
  if fnd > 1 then
    local _, nmb = reaper.GetUserInputs("Multiple Reverb Tracks Found, input number:", 1, "number:", 0)
    nmb = tonumber(nmb)
    if _ == true and nmb ~= 0 and nmb <= fnd then
      for i = 1, #sel_tr do
        reaper.CreateTrackSend( sel_tr[i], store[nmb] )
      end
    end
  end
  
reaper.PreventUIRefresh( -1 )
reaper.Undo_EndBlock2( 0, "Route Selected Tracks to Reverb", 1)
```
To default send level to `-∞ dB`
```
      send_idx = reaper.CreateTrackSend( sel_tr[i], store[fnd] )
      reaper.SetTrackSendInfo_Value( sel_tr[i], 0, send_idx, "D_VOL", 0.0)
```
One could also put this in a function with the `Reverb` string a parameter. So we could use
the same code to do sends to tracks named `Delay`.

## Comments and Improvement
These comments were made by a `[deleted]` user on the Reddit linked above.

1. You're counting how many time you find a track named `"Reverb"` via the variable `fnd` as you insert those tracks into an array (`store`). There's no need to maintain a separate count. That number is part of the array, accessed via `#store`. You're already using this fact to insert elements into the array; that's what the `#store` in `store[#store+1] = str` means. So the `fnd` variable is superfluous.

1. `string.match(trackName, "Reverb")` can be written `trackName:match("Reverb")`.

1. `if blah ~= nil then` can be written `if blah then`. The `~= nil is implicit`; that's what `true` means in Lua.

1. Regarding `_ == true`: if `_` is equal to true then `_` and `_ == true` produce the same value, so the `== true` portion is unnecessary.

1. `_` is sometimes used if a value is being discarded, but here the value is actually being used and so should be named.

1. You only use `tr_cnt` once, so it doesn't really need to even be stored (matter of taste).

1. `#store > 1` is a superset of `#store == 1` and contains duplicate code. You can eliminate the duplication by folding these cases together.

1. You have a comment indicating where someone can edit the code if they use a different reverb track name. It's easier for a user to find and edit that kind of configuration stuff if you put it to the top of the script.

1. Naming a variable `store` is a lot like naming it `variable`. Yes, we know it stores something, but what does it store? The name should reflect its content. Given that your other variable for storing tracks is called `sel_tr` (presumably short for selected tracks), you could call this one `rev_tr` (to maintain the same level of terseness, though I'd probably just call them something like `selected` and `reverb`).

1. There's no feedback for when no tracks are selected.

1. When you prompt the user to choose which reverb track to send to, you give them a useless default and give no feedback if they type in an invalid option.

1. If you're iterating through an array using a `for i=1,N` and you only use `i` to index the array, you can use the `ipairs` iterator instead and have a tidier loop body.

1. If you wrap the body of your script in a function, you can 
    1. use early returns to abort and
    1. nicely group the UI/undo handling stuff together.

## Improved Version
```lua
local reverbTrackName = "Reverb" -- Change for any name you like

function main()
    local sel_tr = {}
    local reverb_tr = {}

    for i = 0, reaper.CountSelectedTracks(0)-1 do
        sel_tr[#sel_tr+1] = reaper.GetSelectedTrack(0,i)
    end

    if #sel_tr == 0 then
        reaper.ShowMessageBox("No tracks selected!", "Error!", 0)
        return
    end

    -- find all reverb tracks
    for trackIndex = 0, reaper.CountTracks(0) - 1 do
        local track = reaper.GetTrack(0, trackIndex)
        local _, trackName = reaper.GetSetMediaTrackInfo_String(track, 'P_NAME', '', false)
        if trackName:match(reverbTrackName) then
            reverb_tr[#reverb_tr+1] = track
        end
    end

    if #reverb_tr == 0 then
        reaper.ShowMessageBox("No tracks with the name " + reverbTrackName + " found!", "Error!", 0)
        return
    elseif #reverb_tr > 1 then
        local ok, nmb = reaper.GetUserInputs("Which reverb track should we send to?", 1, "number:", 1)
        if not ok then
            return
        end
        nmb = tonumber(nmb)
        if nmb < 1 or nmb > #reverb_tr then
            reaper.ShowMessageBox("That's not a valid reverb track.", "Error!", 0)
            return
        end
        reverb_tr[1] = reverb_tr[nmb]
    end

    for i,track in ipairs(sel_tr) do
        reaper.CreateTrackSend( track, reverb_tr[1] )
    end
end

reaper.Undo_BeginBlock2( 0 )
reaper.PreventUIRefresh( 1 )
main()
reaper.PreventUIRefresh( -1 )
reaper.Undo_EndBlock2( 0, "Route Selected Tracks to Reverb", 1)
```