字符串中的LUA的模式寻找一个url

Question

使用Lua模式匹配，我想能够解析字符串，找到下面的网址

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

斜杠可以是可选的但如果包括它必须能够找到嵌套的文件夹如：

test.com/test/ 

这样我就可以使用单个模式匹配找到url。问题是，我使用的所有示例要么不工作，要么导致魔兽世界永远不会让加载屏幕出现一些我自己无法解决的错误。

我不再拥有我在代码中使用的模式，所以我可以使用能够工作而不会挂钩不正确的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：印

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，因为它看起来像一些乌克兰网站:-)