get_property() — rsyslog 8.2412.0 documentation

# get_property()

## Purpose

get_property(rsyslog_variable, key_str)

Provides ability to get a rsyslog variable or property using dynamically evaluated parameters. The first parameter is a valid rsyslog variable or property, the second parameter is a key string, or index value.

## Example

In the following example, a json string is parsed using parse_json(), and placed into the variable `$!parsed`. The get_property function is then used to get property fields from `$!parsed`.

    set $.ret = parse_json("{\"offsets\": [ { \"a\": 9, \"b\": 0 },\
                                            { \"a\": 9, \"b\": 3 } ],\
                                            \"boolval\": true,\
                                            \"int64val\": 1234567890,\
                                            \"nullval\": null,\
                                            \"doubleval\": 12345.67890 }", "\$!parsed");

    # get different fields from $!parsed here
    if $.ret == 0 then {
       # dynamically evaluate different fields in $!parsed

       # do dynamic indexing into array
       $.index = 1;
       # set $.ret = { "a": 9, "b": 3}
       set $.ret = get_property($!parsed!offsets, $.index);

       # set $.ret = true;
       set $.key = "boolval";
       set $.ret = get_property($!parsed, $.key);

       # null values are evaluated to empty string
       # thus below statement will set $.ret to empty string
       set $.ret = get_property($!parsed, "nullval");

       # evaluates to 1234567890
       set $.key = "int64val";
       set $.ret = get_property($!parsed, $.key);

       # using a key variable, evaluates to 12345.67890
       set $key = "doubleval";
       set $.ret = get_property($!parsed, $key);
    }

    # example of dynamically building key value
    set $.foo!barval = 3;
    # set $.bar = 3;
    set $.bar = get_property($.foo, "bar" & "val");

See also

Help with configuring/using `Rsyslog`:

- Mailing list - best route for general questions

- GitHub: rsyslog source project - detailed questions, reporting issues that are believed to be bugs with `Rsyslog`

See also

Contributing to `Rsyslog`:

- Source project: rsyslog project README.

- Documentation: rsyslog-doc project README

Copyright 2008-2023 Rainer Gerhards (Großrinderfeld), and Others.