Performs Base64 decoding of a field. The decoded value is
subsequently decoded as binary representation of a string
according to the
charset
parameter. To work with actual binary data, use
ISO-8859-1
character set.
To reverse the decoding, use the
base64Encode()
function:
base64Encode(a, as=a) | base64Decode(field=a, as=a)
Parameter | Type | Required | Default Value | Description |
---|---|---|---|---|
as | string | optional[a] | _base64Decode | Name of the field in which to store the decoded value. |
charset | string | optional[a] | UTF-8 | The character set to use when transforming bytes to string. |
Valid Values | ||||
ISO-8859-1 | ||||
UTF-16BE | ||||
UTF-16LE | ||||
UTF-8 | ||||
field [b] | string | required | The field on which to decode Base64 values. | |
[a] Optional parameters use their default value unless explicitly set. |
Hide omitted argument names for this function
Omitted Argument NamesThe argument name for
field
can be omitted; the following forms of this function are equivalent:logscale Syntaxbase64Decode("value")
and:
logscale Syntaxbase64Decode(field="value")
These examples show basic structure only.
Behavior on Invalid Encoding
An input field that does not contain a valid Base64 encoding may result in the following behavior:
Characters outside the base encoding alphabet are ignored.
If the base encoding is invalid, the output field is not created.
When decoding to a code point that is invalid with respect to the selected charset, the invalid code point is replaced with a placeholder character.
base64Decode()
Examples
Click
next to an example below to get the full details.Perform Base64 Decoding of a Field
Perform Base64 decoding of a field using base64Decode()
function
Query
decoded := base64Decode(encoded)
Introduction
In this example, the base64Decode()
function is used to manipulate character strings that are base64
encoded and return a base64-decoded version of the input string.
Step-by-Step
Starting with the source repository events.
- logscale
decoded := base64Decode(encoded)
Decodes the
Base64
value in encoded and stores it in the field decoded (the field on which to decodeBase64
values). The decoded value is subsequently decoded as binary representation of a string according to thecharset
parameter. Thecharset
parameter is the character set to use when transforming bytes to string. To work with binary data, useISO-8859-1
character set. Event Result set.
Summary and Results
The query is used to filter on input fields that do not contain a valid Base64 encoding. When decoding to a code point that is invalid with respect to the selected charset, the invalid code point is replaced with a placeholder character. This process ensures that data can be easily processed by computers.