Question

I have a big XML file (~20 MB) that contains among others such lines:

<BUR value="0.01" />

Now I want to find all lines where value is greater than 0.33. How can I do this in Windows?

Answer 1

Hm. Matching number ranges isn’t regexes’ strong suit.

A regex that would work on arbitrary precision floats (except for exponential notation) could look like this:

<BUR value="0*(?:[1-9]\d*\.\d*|0\.[4-9]\d*|0\.3[4-9]\d*|0\.33(?!0+")\d+)" />

In PowerShell, which comes with Windows Vista, you could iterate over all lines that contain a matching string like this:

$regex = [regex] '(?m)^.*<BUR value="0*(?:[1-9]\d*\.\d*|0\.[4-9]\d*|0\.3[4-9]\d*|0\.33(?!0+")\d+)" />.*$'
$matchdetails = $regex.Match($subject)
while ($matchdetails.Success) {
    # matched text: $matchdetails.Value
    $matchdetails = $matchdetails.NextMatch()
}