Increments the revision of the file and saves it

Increment Revision And Save.lua

-- E.g. if the filename is called "spriteR1.png", it will rename it to "spriteR2.png" and save it.

local spr = app.activeSprite
if not spr then return app.alert "No active sprite" end

local pt = app.fs.filePathAndTitle(spr.filename)
local ext = app.fs.fileExtension(spr.filename)

-- New filename replacing the revision number at the end with its
-- incremented version
local fn = string.gsub(
  pt, "%d+",
  function(s)
    local r = string.format("%d",
                            tonumber(s)+1) -- Increment revisiono

    -- As string.format() doesn't "%*d" we have to add the '0's
    while string.len(r) < string.len(s) do
      r = "0" .. r
    end
    return r
  end) .. "." .. ext

-- Save with the new filename
if not app.fs.isFile(fn) then
  app.command.SaveFileAs{ filename=fn }
else
  app.alert("File " .. fn .. " already exists. We don't want to overwrite it.")
end