feat: add ZipEntry:unixMode() to get unix mode values as octals

Updates tests, and makes the `tour` example display the perms instead of
the raw external attributes.

examples/tour.luau

@@ -22,9 +22,9 @@ local function formatTree(tree: Tree): Tree<string>
 		local truncContents = content:gsub("\n", ""):sub(1, 100)
 
 		result[key] = string.format(
-			"(%d bytes), attrs: 0x%x, content: %s",
+			"(%d bytes), perms: %s, content: %s",
 			fileEntry.size,
-			fileEntry.attributes,
+			fileEntry.unixMode.perms,
 			truncContents .. (if #content > 100 then "..." else "")
 		)
 	end
@@ -35,6 +35,7 @@ end
 local tree: Tree = {}
 type Tree<T = EntryData> = { [string]: T | Tree<T> }
 type EntryData = {
+	unixMode: zip.UnixMode,
 	path: string,
 	size: number,
 	attributes: number,
@@ -69,6 +70,7 @@ reader:walk(function(entry, depth)
 			current[name] = {}
 		else
 			current[name] = {
+				unixMode = assert(entry:unixMode(), "Not a unix file"),
 				path = entry:getPath(),
 				size = entry.size,
 				attributes = entry.attributes,

lib/init.luau

@@ -184,7 +184,7 @@ function ZipEntry.sanitizePath(self: ZipEntry): string
 end
 
 function ZipEntry.compressionEfficiency(self: ZipEntry): number?
-	if self.size == 0 or self.compressedSize == 0 then 
+	if self.size == 0 or self.compressedSize == 0 then
 		return nil
 	end
 
@@ -192,7 +192,25 @@ function ZipEntry.compressionEfficiency(self: ZipEntry): number?
 	return math.round(ratio * 100)
 end
 
--- TODO: More methods for `ZipEntry`, handle octals and unix perms
+function ZipEntry.isFile(self: ZipEntry): boolean
+	return not (self.isDirectory and self:isSymlink())
+end
+
+export type UnixMode = { perms: string, typeFlags: string }
+function ZipEntry.unixMode(self: ZipEntry): UnixMode?
+	if self.versionMadeBy.os ~= "UNIX" then
+		return nil
+	end
+
+	local mode = bit32.rshift(self.attributes, 16)
+	local typeFlags = bit32.band(self.attributes, 0x1FF)
+	local perms = bit32.band(mode, 0x01FF)
+
+	return {
+		perms = string.format("0o%o", perms),
+		typeFlags = string.format("0o%o", typeFlags),
+	}
+end
 
 local ZipReader = {}
 export type ZipReader = typeof(setmetatable({} :: ZipReaderInner, { __index = ZipReader }))

tests/metadata.luau

@@ -121,6 +121,10 @@ return function(test: typeof(frktest.test))
 
 							local entry = assert(zip:findEntry(assert(name)))
 
+							if entry.versionMadeBy.os == "UNIX" then 
+								check.not_nil(entry:unixMode())
+							end
+							
 							local ok, zipinfoResult = pcall(process.spawn, "zipinfo", { file, name })
 							if ok then
 								-- Errors can only occur when there is a non utf-8 file name, in which case