rsyslog
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  • Getting Started with rsyslog
  • Configuration
    • Basic Structure
    • Output Modules
    • Input Modules
    • Parser Modules
    • Message Modification Modules
    • String Generator Modules
    • Library Modules
    • Templates
    • rsyslog Properties
    • The Property Replacer
    • Filter Conditions
    • RainerScript
      • Data Types
      • Expressions
      • Functions
        • Built-in Functions
        • Module Functions
      • Control Structures
      • configuration objects
      • Rsyslog Parameter String Constants
      • Examples
      • Variable (Property) types
      • Lookup Tables
      • General Queue Parameters
      • The rsyslog “call” statement
      • The rsyslog “call_indirect” statement
      • global() configuration object
      • The rsyslog include() object
    • Actions
    • Input
    • Parser
    • timezone
    • Examples
    • Legacy Configuration Directives
    • rsyslog statistic counter
    • Modules
    • Output Channels
    • Dropping privileges in rsyslog
    • Notes on IPv6 Handling in Rsyslog
    • libgcrypt Log Crypto Provider (gcry)
    • libossl Log Crypto Provider (ossl)
    • Dynamic Stats
    • Lookup Tables
    • Percentile Stats
    • Converting older formats to advanced
    • Configuration Formats
    • YAML Configuration Format
    • sysklogd format
    • Additional Resources
    • Compatibility Note
  • FAQ
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  • Reference
rsyslog
  • Configuration
  • RainerScript
  • Functions
  • Built-in Functions
  • View page source

Built-in functions are always available in RainerScript without loading modules.

Built-in Functions

Following functions are available in Rainerscript.

See also Module Functions for loadable function modules.

  • append_json()
  • cnum()
  • cstr()
  • dyn_inc()
  • exec_template()
  • exists()
  • field()
  • format_time()
  • get_property()
  • getenv()
  • int2hex()
  • num2ipv4() / ipv42num()
  • is_in_subnet()
  • is_time()
  • lookup()
  • parse_json()
  • parse_time()
  • percentile_observe()
  • previous_action_suspended()
  • prifilt()
  • random()
  • re_extract()
  • re_extract_i()
  • re_match()
  • re_match_i()
  • replace()
  • script_error()
  • split()
  • strlen()
  • substring()
  • tolower()
  • toupper()
  • ltrim() / rtrim()
  • wrap()

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

Contributing: Source & docs: rsyslog source project

© 2008–2026 Rainer Gerhards and others. Licensed under the Apache License 2.0.

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