luasocket/src/url.lua
Diego Nehab f960b3872a Making progress toward a release
Documented headers.lua
Update copyright date everywhere
Remove RCSID from files
Move version back to 2.1 rather than 2.1.1
Fixed url package to support ipv6 hosts
Changed "domain" to "family" in tcp and udp structures
Implemented getfamily methods
2012-04-23 00:18:45 +08:00

303 lines
11 KiB
Lua

-----------------------------------------------------------------------------
-- URI parsing, composition and relative URL resolution
-- LuaSocket toolkit.
-- Author: Diego Nehab
-----------------------------------------------------------------------------
-----------------------------------------------------------------------------
-- Declare module
-----------------------------------------------------------------------------
local string = require("string")
local base = _G
local table = require("table")
module("socket.url")
-----------------------------------------------------------------------------
-- Module version
-----------------------------------------------------------------------------
_VERSION = "URL 1.0.2"
-----------------------------------------------------------------------------
-- Encodes a string into its escaped hexadecimal representation
-- Input
-- s: binary string to be encoded
-- Returns
-- escaped representation of string binary
-----------------------------------------------------------------------------
function escape(s)
return (string.gsub(s, "([^A-Za-z0-9_])", function(c)
return string.format("%%%02x", string.byte(c))
end))
end
-----------------------------------------------------------------------------
-- Protects a path segment, to prevent it from interfering with the
-- url parsing.
-- Input
-- s: binary string to be encoded
-- Returns
-- escaped representation of string binary
-----------------------------------------------------------------------------
local function make_set(t)
local s = {}
for i,v in base.ipairs(t) do
s[t[i]] = 1
end
return s
end
-- these are allowed withing a path segment, along with alphanum
-- other characters must be escaped
local segment_set = make_set {
"-", "_", ".", "!", "~", "*", "'", "(",
")", ":", "@", "&", "=", "+", "$", ",",
}
local function protect_segment(s)
return string.gsub(s, "([^A-Za-z0-9_])", function (c)
if segment_set[c] then return c
else return string.format("%%%02x", string.byte(c)) end
end)
end
-----------------------------------------------------------------------------
-- Encodes a string into its escaped hexadecimal representation
-- Input
-- s: binary string to be encoded
-- Returns
-- escaped representation of string binary
-----------------------------------------------------------------------------
function unescape(s)
return (string.gsub(s, "%%(%x%x)", function(hex)
return string.char(base.tonumber(hex, 16))
end))
end
-----------------------------------------------------------------------------
-- Builds a path from a base path and a relative path
-- Input
-- base_path
-- relative_path
-- Returns
-- corresponding absolute path
-----------------------------------------------------------------------------
local function absolute_path(base_path, relative_path)
if string.sub(relative_path, 1, 1) == "/" then return relative_path end
local path = string.gsub(base_path, "[^/]*$", "")
path = path .. relative_path
path = string.gsub(path, "([^/]*%./)", function (s)
if s ~= "./" then return s else return "" end
end)
path = string.gsub(path, "/%.$", "/")
local reduced
while reduced ~= path do
reduced = path
path = string.gsub(reduced, "([^/]*/%.%./)", function (s)
if s ~= "../../" then return "" else return s end
end)
end
path = string.gsub(reduced, "([^/]*/%.%.)$", function (s)
if s ~= "../.." then return "" else return s end
end)
return path
end
-----------------------------------------------------------------------------
-- Parses a url and returns a table with all its parts according to RFC 2396
-- The following grammar describes the names given to the URL parts
-- <url> ::= <scheme>://<authority>/<path>;<params>?<query>#<fragment>
-- <authority> ::= <userinfo>@<host>:<port>
-- <userinfo> ::= <user>[:<password>]
-- <path> :: = {<segment>/}<segment>
-- Input
-- url: uniform resource locator of request
-- default: table with default values for each field
-- Returns
-- table with the following fields, where RFC naming conventions have
-- been preserved:
-- scheme, authority, userinfo, user, password, host, port,
-- path, params, query, fragment
-- Obs:
-- the leading '/' in {/<path>} is considered part of <path>
-----------------------------------------------------------------------------
function parse(url, default)
-- initialize default parameters
local parsed = {}
for i,v in base.pairs(default or parsed) do parsed[i] = v end
-- empty url is parsed to nil
if not url or url == "" then return nil, "invalid url" end
-- remove whitespace
-- url = string.gsub(url, "%s", "")
-- get fragment
url = string.gsub(url, "#(.*)$", function(f)
parsed.fragment = f
return ""
end)
-- get scheme
url = string.gsub(url, "^([%w][%w%+%-%.]*)%:",
function(s) parsed.scheme = s; return "" end)
-- get authority
url = string.gsub(url, "^//([^/]*)", function(n)
parsed.authority = n
return ""
end)
-- get query string
url = string.gsub(url, "%?(.*)", function(q)
parsed.query = q
return ""
end)
-- get params
url = string.gsub(url, "%;(.*)", function(p)
parsed.params = p
return ""
end)
-- path is whatever was left
if url ~= "" then parsed.path = url end
local authority = parsed.authority
if not authority then return parsed end
authority = string.gsub(authority,"^([^@]*)@",
function(u) parsed.userinfo = u; return "" end)
authority = string.gsub(authority, ":([^:%]]*)$",
function(p) parsed.port = p; return "" end)
if authority ~= "" then
-- IPv6?
parsed.host = string.match(authority, "^%[(.+)%]$") or authority
end
local userinfo = parsed.userinfo
if not userinfo then return parsed end
userinfo = string.gsub(userinfo, ":([^:]*)$",
function(p) parsed.password = p; return "" end)
parsed.user = userinfo
return parsed
end
-----------------------------------------------------------------------------
-- Rebuilds a parsed URL from its components.
-- Components are protected if any reserved or unallowed characters are found
-- Input
-- parsed: parsed URL, as returned by parse
-- Returns
-- a stringing with the corresponding URL
-----------------------------------------------------------------------------
function build(parsed)
local ppath = parse_path(parsed.path or "")
local url = build_path(ppath)
if parsed.params then url = url .. ";" .. parsed.params end
if parsed.query then url = url .. "?" .. parsed.query end
local authority = parsed.authority
if parsed.host then
authority = parsed.host
if string.find(authority, ":") then -- IPv6?
authority = "[" .. authority .. "]"
end
if parsed.port then authority = authority .. ":" .. parsed.port end
local userinfo = parsed.userinfo
if parsed.user then
userinfo = parsed.user
if parsed.password then
userinfo = userinfo .. ":" .. parsed.password
end
end
if userinfo then authority = userinfo .. "@" .. authority end
end
if authority then url = "//" .. authority .. url end
if parsed.scheme then url = parsed.scheme .. ":" .. url end
if parsed.fragment then url = url .. "#" .. parsed.fragment end
-- url = string.gsub(url, "%s", "")
return url
end
-----------------------------------------------------------------------------
-- Builds a absolute URL from a base and a relative URL according to RFC 2396
-- Input
-- base_url
-- relative_url
-- Returns
-- corresponding absolute url
-----------------------------------------------------------------------------
function absolute(base_url, relative_url)
if base.type(base_url) == "table" then
base_parsed = base_url
base_url = build(base_parsed)
else
base_parsed = parse(base_url)
end
local relative_parsed = parse(relative_url)
if not base_parsed then return relative_url
elseif not relative_parsed then return base_url
elseif relative_parsed.scheme then return relative_url
else
relative_parsed.scheme = base_parsed.scheme
if not relative_parsed.authority then
relative_parsed.authority = base_parsed.authority
if not relative_parsed.path then
relative_parsed.path = base_parsed.path
if not relative_parsed.params then
relative_parsed.params = base_parsed.params
if not relative_parsed.query then
relative_parsed.query = base_parsed.query
end
end
else
relative_parsed.path = absolute_path(base_parsed.path or "",
relative_parsed.path)
end
end
return build(relative_parsed)
end
end
-----------------------------------------------------------------------------
-- Breaks a path into its segments, unescaping the segments
-- Input
-- path
-- Returns
-- segment: a table with one entry per segment
-----------------------------------------------------------------------------
function parse_path(path)
local parsed = {}
path = path or ""
--path = string.gsub(path, "%s", "")
string.gsub(path, "([^/]+)", function (s) table.insert(parsed, s) end)
for i = 1, table.getn(parsed) do
parsed[i] = unescape(parsed[i])
end
if string.sub(path, 1, 1) == "/" then parsed.is_absolute = 1 end
if string.sub(path, -1, -1) == "/" then parsed.is_directory = 1 end
return parsed
end
-----------------------------------------------------------------------------
-- Builds a path component from its segments, escaping protected characters.
-- Input
-- parsed: path segments
-- unsafe: if true, segments are not protected before path is built
-- Returns
-- path: corresponding path stringing
-----------------------------------------------------------------------------
function build_path(parsed, unsafe)
local path = ""
local n = table.getn(parsed)
if unsafe then
for i = 1, n-1 do
path = path .. parsed[i]
path = path .. "/"
end
if n > 0 then
path = path .. parsed[n]
if parsed.is_directory then path = path .. "/" end
end
else
for i = 1, n-1 do
path = path .. protect_segment(parsed[i])
path = path .. "/"
end
if n > 0 then
path = path .. protect_segment(parsed[n])
if parsed.is_directory then path = path .. "/" end
end
end
if parsed.is_absolute then path = "/" .. path end
return path
end