Comment puis-je utiliser les expressions régulières lookahead et lookbehind sous Linux en utilisant find ?

find (les variantes GNU et BSD) ne prennent pas en charge le lookahead/lookbehind. GNU grep ne prend en charge que les variantes d'expressions régulières de base et étendues POSIX, ainsi que quelques autres.

Lookahead et lookbehind sont des éléments d'expression régulière de style Perl, vous devez donc utiliser Perl directement, ou GNU grep avec le -P option, qui interprète ensuite Perl regex.

utilisez la regex perl one-liner en passant la sortie find avec un tube. J'ai utilisé lookbehind (obtenir src liens en html) et anticipation pour " et lui a passé la sortie de curl (html).

bash-3.2# curl stackoverflow.com | perl -0777 -ne '$a=1;while(m/(?<=src\=\")(.*)(?=\")/g){print "Match #".$a." "."$&\n";$a+=1;}'
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  239k  100  239k    0     0  1911k      0 --:--:-- --:--:-- --:--:-- 1919k
Match #1 //ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js
Match #2 //cdn.sstatic.net/Js/stub.en.js?v=fb6157e02696
Match #3 https://ssum-sec.casalemedia.com/usermatch?s=183712&amp;cb=https%3A%2F%2Fengine.adzerk.net%2Fudb%2F22%2Fsync%2Fi.gif%3FpartnerId%3D1%26userId%3D
Match #4 //i.stack.imgur.com/817gJ.png" height="16" width="18" alt="" class="sponsor-tag-img">elasticsearch</a> <a href="/questions/tagged/elasticsearch-2.0" class="post-tag" title="show questions tagged &#39;elasticsearch-2.0&#39;" rel="tag">elasticsearch-2.0</a> <a href="/questions/tagged/elasticsearch-dsl" class="post-tag" title="show questions tagged &#39;elasticsearch-dsl&#39;" rel="tag
Match #5 //i.stack.imgur.com/817gJ.png" height="16" width="18" alt="" class="sponsor-tag-img">elasticsearch</a> <a href="/questions/tagged/sharding" class="post-tag" title="show questions tagged &#39;sharding&#39;" rel="tag">sharding</a> <a href="/questions/tagged/master" class="post-tag" title="show questions tagged &#39;master&#39;" rel="tag
Match #6 //i.stack.imgur.com/tKsDb.png" height="16" width="18" alt="" class="sponsor-tag-img">android</a> <a href="/questions/tagged/linux" class="post-tag" title="show questions tagged &#39;linux&#39;" rel="tag">linux</a> <a href="/questions/tagged/camera" class="post-tag" title="show questions tagged &#39;camera&#39;" rel="tag
Match #7 //i.stack.imgur.com/tKsDb.png" height="16" width="18" alt="" class="sponsor-tag-img">android</a> <a href="/questions/tagged/firebase" class="post-tag" title="show questions tagged &#39;firebase&#39;" rel="tag"><img src="//i.stack.imgur.com/5d55j.png" height="16" width="18" alt="" class="sponsor-tag-img">firebase</a> <a href="/questions/tagged/firebase-authentication" class="post-tag" title="show questions tagged &#39;firebase-authentication&#39;" rel="tag
Match #8 //i.stack.imgur.com/tKsDb.png" height="16" width="18" alt="" class="sponsor-tag-img">android</a> <a href="/questions/tagged/ios" class="post-tag" title="show questions tagged &#39;ios&#39;" rel="tag">ios</a> <a href="/questions/tagged/in-app-purchase" class="post-tag" title="show questions tagged &#39;in-app-purchase&#39;" rel="tag">in-app-purchase</a> <a href="/questions/tagged/piracy-protection" class="post-tag" title="show questions tagged &#39;piracy-protection&#39;" rel="tag
Match #9 //i.stack.imgur.com/tKsDb.png" height="16" width="18" alt="" class="sponsor-tag-img">android</a> <a href="/questions/tagged/unity3d" class="post-tag" title="show questions tagged &#39;unity3d&#39;" rel="tag">unity3d</a> <a href="/questions/tagged/vr" class="post-tag" title="show questions tagged &#39;vr&#39;" rel="tag
Match #10 http://pixel.quantserve.com/pixel/p-c1rF4kxgLUzNc.gif" alt="" class="dno
bash-3.2# date
Mon Oct 24 20:57:11 EDT 2016