Replaces each substring of the specified fields value that matches the given regular expression with the given replacement. LogScale uses JitRex which closely follows the syntax of re2j regular expressions, which has a syntax very close to Java's regular expressions. Check out LogScale Regular Expression Syntax.

ParameterTypeRequiredDefaultDescription
asstringoptional[a]input field Specifies the field to store the replaced string as.
fieldstringoptional[a]@rawstring Specifies the field to run the replacement on.
flagsstringoptional[a]m Specifies other regex flags.
  Valid Values
   dPeriod (.) includes newline characters
   iIgnore case for matched values
   mMulti-line parsing of regular expressions
regex[b]stringrequired  The regular expression to match.
replacementstringoptional[a]"" The string to substitute for each match (same as with).
withstringoptional[a]"" The string to substitute for each match.

[a] Optional parameters use their default value unless explicitly set

[b] The argument name regex can be omitted.

Omitted Argument Names

The argument name for regex can be omitted; the following forms of this function are equivalent:

logscale
replace("value")

and:

logscale
replace(regex="value")

replace() Examples

  • Correct a spelling mistake

    logscale
    replace(regex=propperties, with=properties)

  • Get the integer part of a number. This example uses regex capturing groups, and stores the replacement in the field b, leaving field a untouched. This is the same as using a named capture group, for example:

    logscale
    regex("(?<b>\\d+)\\..*",field=a)
    logscale
    replace("(\\d+)\\..*", with="$1", field=a, as=b)

  • Truncate a message to 100 characters:

    logscale
    replace("^(.{100}).*", with="$1", field=message, as="truncated_message")