You couldn’t (before 2022). The official GitHub searching rules: Due to the complexity of searching code, there are a few restrictions on how searches are performed: Only the default branch is considered. In most cases, this will be the master branch. Only files smaller than 384 KB are searchable. Only repositories with fewer than 500,000 … Read more
Update Now that the question scope has been corrected, I might add something in this regard as well: There are many comparisons between Apache Solr and ElasticSearch available, so I’ll reference those I found most useful myself, i.e. covering the most important aspects: Bob Yoplait already linked kimchy’s answer to ElasticSearch, Sphinx, Lucene, Solr, Xapian. … Read more
You can use the \c escape sequence anywhere in the pattern. For example: /\ccopyright or /copyright\c or even /copyri\cght To do the inverse (case sensitive matching), use \C (capital C) instead.