regex - Can't use ^ to say "all but"

Question

I have a text in which I want to get only the hexadecimal codes. Like: "thisissometextthisistextx64x6fx6ex74x74x72x61x6ex73x6cx61x74x65somemoretextoverhere"

It's possible to get the hex codes with x.. But it doesn't seems I can do something like (^x..) to select everything but the hex codes.

Any workarounds?

Answer 1

You may use a (?s)((?:\x[a-fA-F0-9]{2})+)|. regex (that will match and capture into Group 1 any 1+ sequences of hex values OR will just match any other char including a line break char) and replace with a conditional replacement pattern (?{1}$1 :) (that will reinsert the hex value chain or will replace the match with an empty string):

Find What:      (?s)((?:\x[a-fA-F0-9]{2})+)|.
Replace With: (?{1}$1 :)

Regex Details:

• (?s) - same as . matches newline option ON
• ((?:\x[a-fA-F0-9]{2})+) - Group 1 capturing one or more sequences of
  • \x - a \x
  • [a-fA-F0-9]{2} - 2 letters from a to f or digits
• | - or
• . - any single char.

Replacement pattern:

• (?{1} - if Group 1 matches:
  • $1 - replace with its contents + a newline
  • : - else replace with an empty string
• ) - end of the replacement pattern.