Question

I’m parsing through code using a Perl-REGEX parsing engine in my IDE and I want to grab any variables that look like

$hash->{ hash_key04}

and nuke the rest of the code..

So far my very basic REGEX doesnt do what I expected

(.*)(\$hash\-\>\{[\w\s]+\})(.*)


(
\$
hash
\-\>
\{
  [\w\s]+
\}
)

I know to use replace for this ($1,$2,etc), but match (.*) before and after the target string doesnt seem to capture all the rest of the code!

UPADTED:
tried matching null but of course thats too greedy.

([^\0]*)

What expression in regex should i use to look only for the string pattern and remove the rest?

The problem is I want to be left with the list of $hash->{} strings after the replace runs in the IDE.

Answer 1

This is better approached from the other direction. Instead of trying to delete everything you don’t want, what about extracting everything you do want?

my @vars = $src_text =~ /(\$hash->\{[\w\s]+\})/g;

Breaking down the regex:

    /(                  # start of capture group
       \$hash->         # prefix string with $ escaped
       \{               # opening escaped delimiter
        [\w\s]+         # any word characters or space
       \}               # closing escaped delimiter
    )/g;                # match repeatedly returning a list of captures

---

Here is another way that might fit within your IDE better:

s/(\$hash->\{[\w\s]+\})|./$1/gs;

This regex tries to match one of your hash variables at each location, and if it fails, it deletes the next character and then tries again, which after running over the whole file will have deleted everything you don’t want.