How to regex everything that is enclosed between two certain strings in visual selection

Question

I want to find the string enclosed by string1 and string2 and replace it with something else. I got a few lines that look something like

some_string_and_string1_some_rndom_string_string2_and_more
sme_string_and_string1_some_random_string_string2_and_more
some_string_and_string1_some_random_string_string2_and_mre
...

I thought the regex to match everything enclosed by string1 and string2 is

/^string1.*string2$

So the regex would match

string1_some_rndom_string_string2
string1_some_random_string_string2
string1_some_random_string_string2
...

But if I select the lines and try

:'<,'>s/^string1.*string2$

I get

Pattern not found: ^string1.*string2$

What am I doing wrong?

Answer 1

Don't use ^ and $. ^ is start of a line - which means that expression you're looking for needs to be at the very beginning of a line. The same goes for $, which means end of a line. In you're case there is something between ^ and string1/$ and string2, and regex expects that string1 will be first, and it finds some_string_and_ instead.

string1.*string2

should be enough.

Answer 2

Another thing to look at is if you have set nomagic in your .vimrc.

See help magic:

Examples:
after:    \v       \m       \M       \V         matches
                'magic' 'nomagic'
          $        $        $        \$         matches end-of-line
          .        .        \.       \.         matches any character
          *        *        \*       \*         any number of the previous atom

You can temporarily change it with \m (or \v):

:'<,'>s/\mstring1.*string2

or use

:'<,'>s/string1\.\*string2