Lua os.execute return value

Is it possible to read the following from the local variable in Lua?

local t = os.execute("echo 'test'")
print(t)

I just want to achieve this: whenever os.execute returns any value, I would like to use it in Lua - for example echo 'test' will output test in the bash command line - is that possible to get the returned value (test in this case) to the Lua local variable?

You can use io.popen() instead. This returns a file handle you can use to read the output of the command. Something like the following may work:

local handle = io.popen(command)
local result = handle:read("*a")
handle:close()

Note that this will include the trailing newline (if any) that the command emits.

function GetFiles(mask)
   local files = {}
   local tmpfile = '/tmp/stmp.txt'
   os.execute('ls -1 '..mask..' > '..tmpfile)
   local f = io.open(tmpfile)
   if not f then return files end  
   local k = 1
   for line in f:lines() do
      files[k] = line
      k = k + 1
   end
   f:close()
   return files
 end