在字符串 lua 模式中查找 url

Question

使用 Lua 模式匹配我希望能够解析字符串并找到以下 URL

http://www.test.com/
www.test.com/
test.com/
test-test.test.com/

斜线可以是可选的，但如果包含它必须能够找到嵌套文件夹，例如：

test.com/test/

这样我可以使用单个模式匹配来查找 url。问题是我使用的所有示例要么不起作用，要么导致魔兽世界永远不会离开加载屏幕出现我自己无法解决的错误。

我不再有我在代码中使用的模式，因此我可以使用一种有效且不会挂钩不正确 URL 的模式。如果以后需要，我会想出一些。

Answer 1

-- all characters allowed to be inside URL according to RFC 3986 but without
-- comma, semicolon, apostrophe, equal, brackets and parentheses
-- (as they are used frequently as URL separators)
local text_with_URLs = [[
   <a href="http://www.lua.org:80/manual/5.2/contents.html">L.ua 5.2</a>
   [url=127.0.0.1:8080]forum link[/url]
   intranet links: http://test, http://retracker.local/announce
   [markdown link](https://74.125.143.101/search?q=Who+are+the+Lua+People%3F)
   long subdomain chain: very.long.name.of.my.site.co.uk
   auth link: ftp://user:pwd@site.com/path - not recognized yet :(
]]

local domains = [[.ac.ad.ae.aero.af.ag.ai.al.am.an.ao.aq.ar.arpa.as.asia.at.au
   .aw.ax.az.ba.bb.bd.be.bf.bg.bh.bi.biz.bj.bm.bn.bo.br.bs.bt.bv.bw.by.bz.ca
   .cat.cc.cd.cf.cg.ch.ci.ck.cl.cm.cn.co.com.coop.cr.cs.cu.cv.cx.cy.cz.dd.de
   .dj.dk.dm.do.dz.ec.edu.ee.eg.eh.er.es.et.eu.fi.firm.fj.fk.fm.fo.fr.fx.ga
   .gb.gd.ge.gf.gh.gi.gl.gm.gn.gov.gp.gq.gr.gs.gt.gu.gw.gy.hk.hm.hn.hr.ht.hu
   .id.ie.il.im.in.info.int.io.iq.ir.is.it.je.jm.jo.jobs.jp.ke.kg.kh.ki.km.kn
   .kp.kr.kw.ky.kz.la.lb.lc.li.lk.lr.ls.lt.lu.lv.ly.ma.mc.md.me.mg.mh.mil.mk
   .ml.mm.mn.mo.mobi.mp.mq.mr.ms.mt.mu.museum.mv.mw.mx.my.mz.na.name.nato.nc
   .ne.net.nf.ng.ni.nl.no.nom.np.nr.nt.nu.nz.om.org.pa.pe.pf.pg.ph.pk.pl.pm
   .pn.post.pr.pro.ps.pt.pw.py.qa.re.ro.ru.rw.sa.sb.sc.sd.se.sg.sh.si.sj.sk
   .sl.sm.sn.so.sr.ss.st.store.su.sv.sy.sz.tc.td.tel.tf.tg.th.tj.tk.tl.tm.tn
   .to.tp.tr.travel.tt.tv.tw.tz.ua.ug.uk.um.us.uy.va.vc.ve.vg.vi.vn.vu.web.wf
   .ws.xxx.ye.yt.yu.za.zm.zr.zw]]
local tlds = {}
for tld in domains:gmatch'%w+' do
   tlds[tld] = true
end
local function max4(a,b,c,d) return math.max(a+0, b+0, c+0, d+0) end
local protocols = {[''] = 0, ['http://'] = 0, ['https://'] = 0, ['ftp://'] = 0}
local finished = {}

for pos_start, url, prot, subd, tld, colon, port, slash, path in
   text_with_URLs:gmatch'()(([%w_.~!*:@&+$/?%%#-]-)(%w[-.%w]*%.)(%w+)(:?)(%d*)(/?)([%w_.~!*:@&+$/?%%#=-]*))'
do
   if protocols[prot:lower()] == (1 - #slash) * #path and not subd:find'%W%W'
      and (colon == '' or port ~= '' and port + 0 < 65536)
      and (tlds[tld:lower()] or tld:find'^%d+$' and subd:find'^%d+%.%d+%.%d+%.$'
      and max4(tld, subd:match'^(%d+)%.(%d+)%.(%d+)%.$') < 256)
   then
      finished[pos_start] = true
      print(pos_start, url)
   end
end

for pos_start, url, prot, dom, colon, port, slash, path in
   text_with_URLs:gmatch'()((%f[%w]%a+://)(%w[-.%w]*)(:?)(%d*)(/?)([%w_.~!*:@&+$/?%%#=-]*))'
do
   if not finished[pos_start] and not (dom..'.'):find'%W%W'
      and protocols[prot:lower()] == (1 - #slash) * #path
      and (colon == '' or port ~= '' and port + 0 < 65536)
   then
      print(pos_start, url)
   end
end

输出：

13    http://www.lua.org:80/manual/5.2/contents.html
61    L.ua
82    127.0.0.1:8080
197   https://74.125.143.101/search?q=Who+are+the+Lua+People%3F
281   very.long.name.of.my.site.co.uk
133   http://test
146   http://retracker.local/announce

第二行被打印了，因为它看起来像一些乌克兰网站:-)