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Filter Expressions

The filter expression language allows for data set filtering using a simplified expression language. The language itself supports boolean logic (and, or, ()) and equivalences (>=, <=, !=, ==). String values are wrapped in quotes ("", '') and columns values can be accessed using the column name. Regex patterns can be provided as well, and require the pattern to be wrapped in forward slashes (\).

The filter expression language is used with the filter command, tag command, and the globally available --filter flag.

Advanced features​

null filtering​

The filter expression can be used to filter based on null values using the null keyword. For example:

... || filter "status != null"

Regex patterns​

The filter expression can contain regex patterns wrapped in forward slashes (/). PCRE flags are supported.

Example excluding rows containing the string https://www.{ANY ALPAHANUMERIC}.com/ in the url column:

... || filter "url != /https:\/\/www.[A-Za-z0-9]+.com/"

Example including rows containing the string https://www.{ANY ALPAHANUMERIC}.com/ in the url column:

... || filter "url == /https:\/\/www.[A-Za-z0-9]+.com/"

Wildcards​

For simpler filtering on wildcard values without a full regex pattern, the filter expression can include wildcards (*) to either include or exclude results based on the chosen comparator (== or !=).

Example excluding rows containing the string https://www.example.com/ in the url column:

... || filter "url != 'https://www.example.com/*'"

Example including rows containing the string https://www.example.com/ in the url column:

... || filter "url == 'https://www.example.com/*'"

Examples​

Filtering for a specific status code​

... || filter "status.code == 200"

The above filter expression will compare the values contained in the status.code column to the value 200.

... || filter 'status.code == "ok"'

The above filter expression will compare the values contained in the status.code column to the value ok.

... || filter "status.code == code"

The above filter expression will compare the values contained in the status.code column to the values contained in another column named code.

... || filter "status.code == /2[0-9][0-9]/"

The above filter expression will compare the values contained in the status.code column to the regex pattern 2[0-9][0-9].

... || filter "status.code == '2*'"

The above filter expression will compare the values contained in the status.code column to the value containing a wildcard 2* (matches on anything, the * wildcard is equivalent to the regex .*).

Boolean filters​

... || filter "((status.code == 303) or (status.code < 300)) and response.data == 'ok'"

The above filter expression uses parentheses to group logical boolean operations together. This filter willinclude rows where the response.data value is ok and the status.code is either 303 or less than 300.