local inst = mc.mcGetInstance();
local currentfile = mc.mcCntlGetGcodeFileName(inst)
source = io.open(currentfile)
local indexval =0
local linenum=0

local StrValue = wx.wxGetTextFromUser("Enter in Text", "Searching For:", "M6");
UpperStrValue = string.upper(StrValue)
LowerStrValue = string.lower(StrValue)
 
while 1 do
    linenum = linenum + 1
    lineread = source:read()
    if not lineread then break end
    if string.match(lineread,UpperStrValue) or string.match(lineread,LowerStrValue)then
        mc.mcCntlSetLastError(inst, "Line:   "..linenum ..":   ".. lineread .. "\n");
        indexval = indexval + 1
    end
end
if indexval == 0 then
        mc.mcCntlSetLastError(inst, "None Found\n");
elseif indexval == 1 then
        mc.mcCntlSetLastError(inst, "Found: "  .. indexval .. " occurrence \n");
elseif indexval > 1 then
        mc.mcCntlSetLastError(inst, "Found: "  .. indexval .. " occurrences \n");      
end