Extract a numeric value using a regular expression

Modified on 2025-06-10 22:51:45 +0200

Hi all, I have a string snmp sensor and I used a REGEX in order to "Extract a numeric value using a regular expression". the value of the SNMP field may be: a string with a number (to be extracted), or empty It works perfect, but when the string is empty (standard behaviour), the sensor goes down. I'd like to transform the "empty" string to a zero value, in order to keep the sensor up. how can I do? (I have last release) many thanks! Gianluca

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Hello, we appreciate your contact.

Unfortunately the Regular Expression numerical extraction within PRTG isn't able to match an empty string. We suggest that you create a custom Sensor instead to be able to handle this sort of logic (if null then value = 0).
There's plentiful of examples for custom-scripts in the KB, this being an great example.

Sep, 2015 - Permalink

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Extract a numeric value using a regular expression

Article CommentsAttention: This article is a record of a conversation with the Paessler support team. The information in this conversation is not updated to preserve the historical record. As a result, some of the information or recommendations in this conversation might be out of date.

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Attention: This article is a record of a conversation with the Paessler support team. The information in this conversation is not updated to preserve the historical record. As a result, some of the information or recommendations in this conversation might be out of date.