字符串中的LUA的模式尋找一個url

Question

使用Lua模式匹配，我想能夠解析字符串，找到下面的網址

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

斜槓可以是可選的但如果包括它必須能夠找到嵌套的文件夾如：

test.com/test/ 

這樣我就可以使用單個模式匹配找到url。問題是，我使用的所有示例要麼不工作，要麼導致魔獸世界永遠不會讓加載屏幕出現一些我自己無法解決的錯誤。

我不再擁有我在代碼中使用的模式，所以我可以使用能夠工作而不會掛鉤不正確的URL的模式。如果以後需要，我會想出一些。

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 

輸出：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，因爲它看起來像一些烏克蘭網站:-)