title: Extract parent domain name from a list of url through Bash ShellScripting
body: <p>I have a list of urls like this:</p>
  
  <pre><code>http://noto.zrobimystrone.pl/pucenter/images/NGdocs/
  http://visionwebmkt.com/unsubscribe.php?M=879552&amp;C=b744d324e38f5f3b0bcf549f1d57a3ab&amp;L=20&amp;N=497
  http://www.meguiatramandai.com.br/unsubscribe.php?M=722&amp;C=8410431be55bf12faac13d18982d71cd&amp;L=1&amp;N=3
  http://www.contatoruy.in/link.php?M=86457&amp;N=4&amp;L=1&amp;F=H
  http://www.maxxivrimoveis.com.br/
  http://www.meguiatramandai.com.br/unsubscribe.php?M=722&amp;C=8410431be55bf12faac13d18982d71cd&amp;L=1&amp;N=2
  http://arm.smilecire.com/ch+urch38146263923bpa.stor/imp-roved258021029his+health212149011
  http://hurl.zonalrems.com/ge.tyo-ur584372780599hea+lth247408058un/der+control21211901
  http://harp.doomyjupe.com/see.this-better/life+58291551346csexdrive663295668+better/how.981692016
  http://beefy.toneyvaws.com/no+tice/how/35306640b+see/app=5429204last/attempt=457943182
  http://kirk.yournjuju.com/shop/sam.sclub-win=ter/58387369768esame+673844946.bett.er-loo.k981686408
  http://idly.theirpoem.com/veri-fy/notice-7853508818b2glob/al=who.43639603inc.lusion-610549278
  http://wva188.suleacatan.com/credit-score/review/-551694841511001sfdghsfdgsdfg63887839
  http://cop.forterins.com/app.lyto=face962540097dtolo+oko.ung268570307yo.un-ger8752507
  http://vni116.gaelsyaray.com/qertqetert//-dghjghjghd5531864856415612229498430
  http://ticket.prategama.com/shop/sam.sclub-win=ter/752490935same+226373195.bett.er-loo.k212801
  http://cbu125.quetxviii.com/cvbnvbn7551116db537203--swrtytry664896546
  http://c5a.dicadodia.com.br/pass4sp09/NetAffProTeste-1.html
  http://snub.woadsbevy.com/ama/zing-753773417oppe-tun/ity+217801.is-here/now=236922473
  http://mkt.livrariacultura.com.br/pub/cc?_ri_=X0Gzc2X%3DWQpglLjHJlYQGgzfB7tPi0PuyyJ71ES
  </code></pre>
  
  <p>I wanna extract only the parents domain names, for example:</p>
  
  <pre><code>http://noto.zrobimystrone.pl/pucenter/images/NGdocs/
  http://visionwebmkt.com/unsubscribe.php?M=879552&amp;C=b744d324e38f5f3b0bcf549f1d57a3ab&amp;L=20&amp;N=497
  http://www.meguiatramandai.com.br/unsubscribe.php?M=722&amp;C=8410431be55bf12faac13d18
  </code></pre>
  
  <p>Into</p>
  
  <pre><code>zrobimystrone.pl
  visionwebmkt.com
  meguiatramandai.com.br
  </code></pre>
  
  <p>I have tried  </p>
  
  <pre><code>awk '{gsub("http://|/.*","")}1' list.txt
  </code></pre>
  
  <p>and got the following results:</p>
  
  <pre><code>noto.zrobimystrone.pl
  visionwebmkt.com
  www.meguiatramandai.com.br
  www.contatoruy.in
  www.maxxivrimoveis.com.br
  www.meguiatramandai.com.br
  arm.smilecire.com
  hurl.zonalrems.com
  harp.doomyjupe.com
  beefy.toneyvaws.com
  </code></pre>
  
  <p>but dont know how to get only the parent name from noto.zrobimystrone.pl for instance.</p>