Read from one line with a specific content till another line with specific content in Lua. How?

Question

In LUA, I would need to read a text file from a line with a specific content to another line with a specific content. How can I do it please?

Here an example

a text file called: aaa.txt

...
...
...
[Main from here on]
line1
line2
line3
...
...
title=Till here
...
...

So I need to count the lines between and starting from the square brakets line [Main from here on] (it's titled so), till the last line called "title=Till here"

Answer 1

This solution is based on io.lines () iterator :

--[[
    This function will return all lines from <file>
    from <from> till <to> or end of file
    both ends included.
--]]
local function readFromTo (file, from, to)
    io.input (file) -- open file.
    local started = false
    local lines = {}
    for line in io.lines () do
        if not started and line == from then
            started = true
        end
        if started then
            lines [#lines + 1] = line
            if line == to then
                -- <to> found:
                return lines
            end
        end
    end
    -- Only if <to> not found:
    return lines
end

print (table.concat (readFromTo ('aaa.txt', '[Main from here on]', 'title=Till here'), '\n'))