Question

I have a regex expression that traverses a string and pulls out 40 values, it looks sort if like the query below, but much larger and more complicated

est(.*)/test>test>(.*)<test><test>(.*)test><test>(.*)/test><test>(.*)/test><test>(.*)/test><test(.*)/test><test>(.*)/test><test>(.*)/test><test>(.*)/test><test>(.*)/test><test>(.*)/test><test>(.*)/test><test>(.*)/test><test>(.*)/test><test>(.*)/test>

My question is how do I use these expressions with the replace command when the number exceeds 9. It seems as if whenever I use \10 it returns the value for \1 and then appends a 0 to the end.

Any help would be much appreciated thanks 🙂

Also I am using UEStudio, but if a different program does it better then no biggie 🙂

Answer 1

Most of the simple Regex engines used by editors aren’t equipped to handle more than 10 matching groups; it doesn’t seem like UltraEdit can. I just tried Notepad++ and it won’t even match a regex with 10 groups.

Your best bet, I think, is to write something fast in a quick language with a decent regex parser. but that wouldn’t answer the question as asked

Here’s something in Python:

import re

pattern = re.compile('(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)')
with open('input.txt', 'r') as f:
    for line in f:
        m = pattern.match(line)
        print m.groups()

Note that Python allows backreferences such as \20: in order to have a backreference to group 2 followed by a literal 0, you need to use \g<2>0, which is unambiguous.

Edit:
Most flavors of regex, and editors which include a regex engine, should follow the replace syntax as follows:

abcdefghijklmnop
search: (.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(?<name>.)(.)
note:    1  2  3  4  5  6  7  8  9  10 11 12 13
value:   a  b  c  d  e  f  g  h  i  j  k  l  m
replace result:
    \11      k1      i.e.: match 1, then the character "1"
    ${12}    l       most should support this
    ${name}  l       few support named references, but use them where you can.

Named references are usually only possible in very specific flavor of regex libraries, test your tool to know for sure.