# HashXX

## Purpose

Generates hash for a given string.

### hash32(literal_string) / hash32(literal_string, seed)

> Generates a 32 bit hash of the given string.

>   - Seed is an optional parameter with default = 0.

>   - If seed is not a valid number, then 0 is returned.

### hash64(literal_string) / hash64(literal_string, seed)

> Generates a 64 bit hash of the given string.

>   - Seed is an optional parameter with default = 0.

>   - If seed is not a valid number, then 0 is returned.

Warning

- Default hash implementation is non-crypto.

- To use xxhash enable compile time flag.

## Example

    module(load="fmhash")

    set $.hash = hash64($!msg!field_1 & $!msg!field_2 & $!msg!field_3)
    set $!tag= $syslogtag & $.hash;
    //send out

See also

Hash based sampling

Support: rsyslog Assistant | GitHub Discussions | GitHub Issues: rsyslog source project

Contributing: Source & docs: rsyslog source project

© 2008–2025 Rainer Gerhards and others. Licensed under the Apache License 2.0.