Regular Expressions
For advanced searches, enable Regular expression (RegEx) in the Find pane. Your search text is then interpreted as a pattern rather than as literal text.
Enabling RegEx
- Open the Find pane and type your pattern.
- Enable the Regular expression (RegEx) option.
- Start the search.
When RegEx is enabled, the Whole word option is disabled because it does not apply to patterns. The Match case option still applies: with it off, the pattern matches case-insensitively.
Syntax
O&O RegEditor uses the ECMAScript regular-expression syntax. A few useful elements:
| Pattern | Matches |
|---|---|
. | Any single character. |
^ / $ | The start / end of the text. |
a|b | Either a or b. |
[0-9] | Any digit. |
\d, \w, \s | A digit, a word character, or whitespace. |
*, +, ? | Zero-or-more, one-or-more, zero-or-one of the preceding element. |
{2,4} | Between two and four repetitions. |
Examples
| Goal | Pattern |
|---|---|
Find Dword or Bin | Dword|Bin |
Find a value whose data is exactly StrVal | ^StrVal$ |
Find entries ending in .exe | \.exe$ |
| Find a GUID-like value | \{[0-9A-Fa-f-]+\} |
Invalid Patterns
If a pattern cannot be compiled — for example an unbalanced bracket such as [invalid — O&O RegEditor shows an error message and does not start the search. Correct the pattern and try again.
Regular-expression searches can match a lot. Select a specific key before searching so the result list stays manageable while you refine the pattern.