Because grep is not a "full text search tool". Full text search [1] is different from regular expression search. [1] https://en.wikipedia.org/wiki/Full-text_s

Because grep is not a "full text search tool". Full text search [1] is different from regular expression search. [1] https://en.wikipedia.org/wiki/Full-text_search https://en.wikipedia.org/wiki/Full-text_search