Extracts the fields from the specified field using a regular expression.


rex field=FIELD "REGEX"
Required Parameter
Target field from which to extract the string using a regular expression.
Extended regular expression to give the field name. If you specify the group in the form of (?<field>) in the regular expression, the command extracts the string matched to the group to the field field.


  1. Look up a file path starting with GET /game/flash/ or POST /game/flash from the line field and then return the matched ones to the filename field.

    rex field=line "(GET|POST) /game/flash/(?<filename>([^ ]*))"
  2. Extract the string in the timestamp pattern from the line field and assign it to the timestamp field.

    rex field=line "(?<timestamp>\d+-\d+-\d+ \d+:\d+:\d+)"
  3. Extract the strings from the line field and assign them to the url and querystring fields.

    rex field=line "(GET|POST) (?<url>[^ ]*) (?<querystring>[^ ]*) "