Extracting a substring from a large string in Erlang

Question

I need to search for a substring in a string and return that if it is there in the string. What is the best way to do that in Erlang? Note that i dont know the place that substring happens in the bigger string so i need to do a search for that.

Answer 1

You can use a regular expression:

> re:run("foobarbaz", "bar", [{capture, first, list}]).
{match,["bar"]}

See the documentation for re:run/3 for more information. In particular you may find that a different capture option suits your need.

Or if you don't need all the features of regular expressions, string:str/2 might be enough:

> string:str(" Hello Hello World World ", "Hello World").
8

Answer 2

This small function may help you. It returns true if the small string can be found in the big string, otherwise it returns false.

string_contains(Big, Small)->
    string:str(Big, Small) > 0.