512mb-bot/libraries/file.lua

--This bot is heavily dependent on file operations, therefore this library exists.
local file = {}
local json
if pcall(import,"json") then
    json = import("json")
elseif pcall(require,"json") then
    json = require("json")
end
file.safe = true
file.read = function(filename,mode)
    assert(type(filename) == "string","string expected, got "..type(filename))
    local mode = mode or "*a"
    local temp_file,err = io.open(filename,r)
    if err then
        if not file.safe then error(err) else
            ret_string = ""
        end
    else
        ret_string = temp_file:read(mode)
        temp_file:close()
    end
    return ret_string,err
end

file.write = function(filename,write)
    assert(type(filename) == "string", "string expected, got "..type(filename))
    assert(type(write) == "string", "string expected for argument #2, got "..type(write))
    local temp_file,err = io.open(filename,"w+")
    local status = false
    if err then
        if not file.safe then error(err) else
            status = false
        end
    else
        temp_file:write(write)
        temp_file:close()
        status = true
    end
    return status,err
end

file.exists = function(filename)
    local file = io.open(filename,"r")
    if file then
        file:close()
        return true
    else
        return false
    end
end

file.existsDir = function(filename)
    local file = io.open(filename.."/stuff","w")
    if file then
        file:close()
        os.remove(filename.."/stuff")
        return true
    else
        return false
    end
end

file.ls = function(path)
    if file.existsDir(path) then 
        local ls_handle = io.popen("ls -1 "..path,"r")
        local ls_data = ls_handle:read("*a")
        ls_handle:close()
        return ls_data 
    else 
        return false, "No such file or directory" 
    end
end

if json then
    file.readJSON = function(filename,default)
        assert(type(filename) == "string","string expected, got "..type(filename))
        local json_data,err = file.read(filename,"*a")
        local table_data, status
        if err then
            if not file.safe then error(err) else
                status = err
                table_data = default or {}
            end
        else
            table_data,_,err = json.decode(json_data)
            if not table_data then
                if not file.safe then error(err) else
                    status = err
                    table_data = default or {}
                end
            end
        end
        return table_data, status
    end
    file.writeJSON = function(filename,table_data)
        assert(type(filename) == "string","string expected, got "..type(filename))
        assert(type(table_data) == "table","table expected, got "..type(table_data))
        local status = false
        local status,json_object,_,err = pcall(function() return json.encode(table_data) end)
        if not status then
            if not file.safe then error(err) else
                status = false
                err = json_object
            end
        else
            if json_object then
                status,err = file.write(filename,json_object)
            end
        end
        return status, err
    end
end
return file