implemented platform specific code

implemented filesys module
added an rfind function to globals.lua

scripts/api/filesys.lua

@@ -0,0 +1,17 @@
+require "api.platform"
+
+local FileSys = require "api.platform.filesys_impl"
+
+if os.name() == Platform.WINDOWS then
+    require "api.platform.win.filesys"
+elseif os.name() == Platform.LINUX then
+    require "api.platform.linux.filesys"
+elseif os.name() == Platform.MACOS then
+    game.Log("MacOS specific implementation missing, loading linux filesys module", game.LOGGER_WARNING)
+    require "api.platform.linux.filesys"
+else
+    game.Log("OS Platform not recognized, loading linux filesys module", game.LOGGER_WARNING)
+    require "api.platform.linux.filesys"
+end
+
+return FileSys

scripts/api/platform.lua

@@ -0,0 +1,39 @@
+
+---@note setup code from: https://stackoverflow.com/a/30960054
+local BinaryFormat = package.cpath:match("%p[\\|/]?%p(%a+)")
+
+if BinaryFormat == "dll" then
+    function os.name()
+        return "Windows"
+    end
+elseif BinaryFormat == "so" then
+    function os.name()
+        return "Linux"
+    end
+elseif BinaryFormat == "dylib" then
+    function os.name()
+        return "MacOS"
+    end
+end
+
+BinaryFormat = nil
+
+Platform = {
+    WINDOWS = "Windows",
+    LINUX = "Linux",
+    MACOS = "MacOS"
+}
+
+---Get OS platform lua is running on
+function GetPlatform()
+    return os.name()
+end
+
+---Merge base module table with implementation table, overwriting base
+---@param base any
+---@param implementation any
+function MergeModules(base, implementation)
+    for key, value in pairs(implementation) do
+        base[key] = value
+    end
+end

scripts/api/platform/filesys_impl.lua

@@ -0,0 +1,126 @@
+require "common.globals"
+
+---@class FileSys
+local FileSys = {
+    __name = "FileSys",
+    sep = "/"
+}
+
+---Return a normalized absolutized version of `path`
+---@param path string
+---@return string
+function FileSys.abspath(path)
+    return FileSys.normpath(FileSys.join(FileSys.getcwd(), path))
+end
+
+---Return the base name of `path`
+---@param path string
+---@return string
+function FileSys.basename(path)
+    return string.sub(path, string.rfind(path, FileSys.sep, 1, true) + 1)
+end
+
+---Return the directory name of `path`
+---@param path string
+---@return string
+function FileSys.dirname(path)
+    return FileSys.split(path)[1]
+end
+
+---Return true if `path` refers to an existing path
+---@param path string
+---@return boolean, string?
+function FileSys.exists(path)
+    local ok, err, code = os.rename(path, path)
+    if not ok then
+        game.Log("err: "..err..", code: "..code, game.LOGGER_DEBUG)
+        if code == 13 then
+            -- Permission denied, but it exists
+            return true
+        end
+    end
+    return ok, err
+end
+
+---Return a string representing the current working directory
+---@return string
+function FileSys.getcwd()
+    assert(false, FileSys.__name .. ".getcwd() : Not Implemented")
+    return ""
+end
+
+---Join one or more path components with the platform specific separator
+---@param path string
+---@param ... string
+---@return string
+function FileSys.join(path, ...)
+    local vargs = { select(1, ...) }
+    local joinedpath = path
+
+    for _, value in ipairs(vargs) do
+        joinedpath = joinedpath .. FileSys.sep .. value
+    end
+
+    return joinedpath
+end
+
+---Normalize `path`, collapse redundant separators and up references
+---@param path string
+---@return string
+function FileSys.normpath(path)
+    local sep = FileSys.sep
+
+    --remove multiple slashes
+    path = path:gsub("("..sep..")"..sep.."+", "%1")
+
+    --remove './'
+    path = path:gsub("%."..sep, "")
+
+    --remove all up references
+    local count = 0
+    local upRefPattern = "%w+"..sep.."%.%."..sep
+    repeat
+        path, count = path:gsub(upRefPattern, "")
+    until count ~= 0
+
+    --remove last slash
+    path = path:gsub("(.-)"..sep.."$", "%1")
+
+    return path
+end
+
+---Return a relative filepath to `path`, optionally relative to `relativeTo`
+---@param path string
+---@param relativeTo? string
+---@return string
+function FileSys.relpath(path, relativeTo)
+    relativeTo = relativeTo or FileSys.getcwd()
+    path = path:sub(path:find(relativeTo, 1, true)[2] + 1)
+    return path
+end
+
+---Return a list of files and directory names in `path`
+---@param path string
+---@return string[]
+function FileSys.scandir(path)
+    assert(false, FileSys.__name .. ".scandir() : Not Implemented")
+    return {}
+end
+
+---Split `path` to (head, tail), tail is the last component, head is everything else
+---@param path string
+---@return string, string
+function FileSys.split(path)
+    local lastSep = path:rfind(FileSys.sep, 1, true)
+    return path:sub(1, lastSep), path:sub(lastSep + 1)
+end
+
+---Split `path` to (root, ext), such that `root + ext == path`, ext is either empty or starts with a '.'
+---@param path string
+---@return string, string
+function FileSys.splitext(path)
+    local lastSep = path:rfind(".", 1, true)
+    return path:sub(1, lastSep - 1), path:sub(lastSep)
+end
+
+return FileSys

scripts/api/platform/linux/filesys.lua

@@ -0,0 +1,37 @@
+local FileSys = require "api.platform.filesys_impl"
+
+FileSys.sep = "/"
+
+function FileSys.getcwd()
+    local cwd, popen = "", io.popen
+    local pfile, err = popen("pwd")
+
+    if not pfile or err ~= 0 then
+        game.Log(tostring(FileSys) .. ".getcwd() : popen failed executing " .. tostring(err), game.LOGGER_ERROR)
+        return nil
+    end
+
+    cwd = pfile:read()
+    pfile:close()
+
+    return cwd
+end
+
+function FileSys.scandir(path)
+    local i, t, popen = 0, {}, io.popen
+    local pfile, err = popen('find "' .. path .. '" -maxdepth 1 -print0')
+
+    if not pfile or err ~= 0 then
+        game.Log(tostring(FileSys) .. ".scandir() : popen failed executing " .. tostring(err), game.LOGGER_ERROR)
+        return nil
+    end
+
+    for filename in pfile:lines() do
+        i = i + 1
+        t[i] = filename
+    end
+
+    pfile:close()
+
+    return t
+end

scripts/api/platform/win/filesys.lua

@@ -0,0 +1,46 @@
+local FileSys = require "api.platform.filesys_impl"
+
+FileSys.sep = "\\"
+
+function FileSys.getcwd()
+    local cwd, popen = "", io.popen
+    local pfile, err = popen("cd")
+
+    if not pfile or err ~= 0 then
+        game.Log(tostring(FileSys) .. ".getcwd() : popen failed executing " .. tostring(err), game.LOGGER_ERROR)
+        return nil
+    end
+
+    cwd = pfile:read()
+    pfile:close()
+
+    return cwd
+end
+
+local baseNormpath = FileSys.normpath
+function FileSys.normpath(path)
+    path = baseNormpath(path)
+
+    path = path:gsub("/", "\\")
+
+    return path
+end
+
+function FileSys.scandir(path)
+    local i, t, popen = 0, {}, io.popen
+    local pfile, err = popen('dir "' .. path .. '" /b /ad')
+
+    if not pfile or err ~= 0 then
+        game.Log(tostring(FileSys) .. ".scandir() : popen failed executing " .. tostring(err), game.LOGGER_ERROR)
+        return nil
+    end
+
+    for filename in pfile:lines() do
+        i = i + 1
+        t[i] = filename
+    end
+
+    pfile:close()
+
+    return t
+end

scripts/common/globals.lua

@@ -8,3 +8,15 @@ game.MOUSE_MIDDLE = 2
 
 game.KNOB_LEFT = 0
 game.KNOB_RIGHT = 1
+
+-- some cool extensions to the builtins ----------------------------------------
+
+---Looks for the last match of pattern in the string.
+---@param s string
+---@param pattern string
+---@param init? integer
+---@param plain? boolean
+function string.rfind(s, pattern, init, plain)
+    pattern = pattern:reverse()
+    return s:len() - s:reverse():find(pattern, init, plain) + 1
+end