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.
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:logscalebase64Decode("field")
and:
logscalebase64Decode(field="field")
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
Perform Base64 Decoding of a Field
Query
decoded := base64Decode(encoded)
Introduction
Base64 is used to encode binary data as printable text. This
allows you to transport binary over protocols or mediums that
cannot handle binary data formats and require simple text. For
example, encoding an attachment as Base64 before sending, and then
decoding when received, assures older SMTP servers will not
interfere with the attachment. 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.