The Number plug-in is displayed when you choose Number in the Filter Kind pop-up menu in the Nouveau / Éditer Filtre.
This plug-in is used by the default Number Changed, Number More than 95%, Number Out of Range, and other filters.
This plug-in expects the input text to be a valid number, so is typically used after a Find or Block filter to narrow down the text. It converts the text to a number, optionally ignoring specified characters, and with a customizable decimal separator so you can match the format of the text.
It then compares that number against either a fixed number, or the number from the previous check, plus or minus some delta. It can compare using "is", "is not", "is greater than", "is less than", "is in range" or "is not in range".
The filter results in either a change or failure, as desired. So you can use this to detect if a disk is getting full, a price has changed by a specified threshold, a file count has changed, or many other uses.
This filter outputs the input text. If the checkbox to detect changes in the Options page is on, it results in a Changed status if the numeric condition is true, or Unchanged if false. If that checkbox is off, it results in a Failure status if the condition is true, or Unchanged if false. A custom error message can be entered.