ruby, using regex to find something in between two strings

Question

Using Ruby + regex, given:

[email protected]

I want to obtain just: 31313131313

ie, what is between starting-middle+ and mysite.com

Here's what I have so far:

to = '[email protected]'

to.split(/\+/@mysite.com.*/).first.strip

Answer 1

Between 1st + and 1st @:

to[/\+(.*?)@/,1]

Between 1st + and last @:

to[/\+(.*)@/,1]

Between last + and last @:

to[/.*\+(.*)@/,1]

Between last + and 1st @:

to[/.*\+(.*?)@/,1]

Answer 2

Here is a solution without regex (much easier for me to read):

i = to.index("+")
j = to.index("@")
to[i+1..j-1]