source/texk/web2c/luatexdir/luasocket/etc/check-links.lua

   1 -----------------------------------------------------------------------------
   2 -- Little program that checks links in HTML files, using coroutines and
   3 -- non-blocking I/O via the dispatcher module.
   4 -- LuaSocket sample files
   5 -- Author: Diego Nehab
   6 -----------------------------------------------------------------------------
   7 local url = require("socket.url")
   8 local dispatch = require("dispatch")
   9 local http = require("socket.http")
  10 dispatch.TIMEOUT = 10
  11
  12 -- make sure the user knows how to invoke us
  13 arg = arg or {}
  14 if table.getn(arg) < 1 then
  15     print("Usage:\n  luasocket check-links.lua [-n] {<url>}")
  16     exit()
  17 end
  18
  19 -- '-n' means we are running in non-blocking mode
  20 if arg[1] == "-n" then
  21     -- if non-blocking I/O was requested, use real dispatcher interface
  22     table.remove(arg, 1)
  23     handler = dispatch.newhandler("coroutine")
  24 else
  25     -- if using blocking I/O, use fake dispatcher interface
  26     handler = dispatch.newhandler("sequential")
  27 end
  28
  29 local nthreads = 0
  30
  31 -- get the status of a URL using the dispatcher
  32 function getstatus(link)
  33     local parsed = url.parse(link, {scheme = "file"})
  34     if parsed.scheme == "http" then
  35         nthreads = nthreads + 1
  36         handler:start(function()
  37             local r, c, h, s = http.request{
  38                 method = "HEAD",
  39                 url = link,
  40                 create = handler.tcp
  41             }
  42             if r and c == 200 then io.write('\t', link, '\n')
  43             else io.write('\t', link, ': ', tostring(c), '\n') end
  44             nthreads = nthreads - 1
  45         end)
  46     end
  47 end
  48
  49 function readfile(path)
  50     path = url.unescape(path)
  51     local file, error = io.open(path, "r")
  52     if file then
  53         local body = file:read("*a")
  54         file:close()
  55         return body
  56     else return nil, error end
  57 end
  58
  59 function load(u)
  60     local parsed = url.parse(u, { scheme = "file" })
  61     local body, headers, code, error
  62     local base = u
  63     if parsed.scheme == "http" then
  64         body, code, headers = http.request(u)
  65         if code == 200 then
  66             -- if there was a redirect, update base to reflect it
  67             base = headers.location or base
  68         end
  69         if not body then
  70             error = code
  71         end
  72     elseif parsed.scheme == "file" then
  73         body, error = readfile(parsed.path)
  74     else error = string.format("unhandled scheme '%s'", parsed.scheme) end
  75     return base, body, error
  76 end
  77
  78 function getlinks(body, base)
  79     -- get rid of comments
  80     body = string.gsub(body, "%<%!%-%-.-%-%-%>", "")
  81     local links = {}
  82     -- extract links
  83     body = string.gsub(body, '[Hh][Rr][Ee][Ff]%s*=%s*"([^"]*)"', function(href)
  84         table.insert(links, url.absolute(base, href))
  85     end)
  86     body = string.gsub(body, "[Hh][Rr][Ee][Ff]%s*=%s*'([^']*)'", function(href)
  87         table.insert(links, url.absolute(base, href))
  88     end)
  89     string.gsub(body, "[Hh][Rr][Ee][Ff]%s*=%s*(.-)>", function(href)
  90         table.insert(links, url.absolute(base, href))
  91     end)
  92     return links
  93 end
  94
  95 function checklinks(address)
  96     local base, body, error = load(address)
  97     if not body then print(error) return end
  98     print("Checking ", base)
  99     local links = getlinks(body, base)
 100     for _, link in ipairs(links) do
 101         getstatus(link)
 102     end
 103 end
 104
 105 for _, address in ipairs(arg) do
 106     checklinks(url.absolute("file:", address))
 107 end
 108
 109 while nthreads > 0 do
 110     handler:step()
 111 end