Re: Reading a conf file

[Valentin <vsl@...>]

Sean Conner wrote:
[ snip ]

>   You already have a parser available to you---Lua.  If the config file is
> just what you said:
> 
> 	a=series
> 	of=key
> 	value=pairs
> 
> A small change:
> 
> 	a='series'
> 	of='key'
> 	value='pairs'
> 	and_a_number=3
> 
> and that can be read in as:
> 
> 	CONF = {} -- your data will end up here
> 	f = loadfile("my-configfile.txt","t",CONF)
> 	f()
> 
> 	print(CONF.a,CONF.and_a_number)

Based on the same idea, but without requiring to add quotes to the conf
file, here a simple function for reading such "INI-like" conf files into
a table. All table values will be strings, and have to be casted
manually to other types if needed.

function loadConfFile (fn)
  local f = io.open(fn, 'r')
  if f==nil then return {} end
  local str = f:read('*a')..'\n'
  f:close()
  local res = 'return {'
  for line in str:gmatch("(.-)[\r\n]") do
    line = line:gsub('^%s*(.-)%s*$"', '%1') -- trim line
    -- ignore empty lines and comments
    if line~='' and line:sub(1,1)~='#' then
      line = line:gsub("'", "\\'") -- escape all '
      line = line:gsub("=%s*", "='", 1)
      res = res..line.."',"
    end
  end
  res = res..'}'
  return loadstring(res)()
end


Usage:
======

-- contents of test.conf
a   =  23

b=hello 'world'

# just a comment
c =    hello world

-- /contents of test.conf

local config = loadConfFile('test.conf')
for k,v in pairs(conf) do
  print(k, v)
end

--> a       23
--> c       hello world
--> b       hello 'world'

Valentin