Struct flexi_logger::LogSpecification

pub struct LogSpecification { /* fields omitted */ }

Immutable struct that defines which loglines are to be written, based on the module, the log level, and the text.

The loglevel specification via string (relevant for methods parse() and env()) works essentially like with env_logger, but we are a bit more tolerant with spaces. Its functionality can be described with some Backus-Naur-form:

<log_level_spec> ::= single_log_level_spec[{,single_log_level_spec}][/<text_filter>]
<single_log_level_spec> ::= <path_to_module>|<log_level>|<path_to_module>=<log_level>
<text_filter> ::= <regex>

• Examples:

  • "info": all logs with info, warn, or error level are written
  • "crate1": all logs of this crate are written, but nothing else
  • "warn, crate2::mod_a=debug, mod_x::mod_y=trace": all crates log warnings and erors, mod_a additional debug messages, and mod_x::mod_y is fully traced

• If you just specify the module, without log_level, all levels will be traced for this module.

• If you just specify a log level, this will be applied as default to all modules without explicit log level assigment. (You see that for modules named error, warn, info, debug or trace, it is necessary to specify their loglevel explicit).

• The module names are compared as Strings, with the side effect that a specified module filter affects all modules whose name starts with this String.
  Example: "foo" affects e.g.

  • foo
  • foo::bar
  • foobaz (!)
  • foobaz::bar (!)

The optional text filter is applied for all modules.

Note that external module names are to be specified like in "extern crate ...", i.e., for crates with a dash in their name this means: the dash is to be replaced with the underscore (e.g. karl_heinz, not karl-heinz).

Methods

impl LogSpecification

fn parse(spec: &str) -> LogSpecification

Returns a log specification from a String.

fn env() -> LogSpecification

Returns a log specification based on the value of the environment variable RUST_LOG, or an empty one.

fn env_or_parse<S: AsRef<str>>(given_spec: S) -> LogSpecification

Returns a log specification based on the value of the environment variable RUST_LOG, or on the given String.

fn default(llf: LevelFilter) -> LogSpecBuilder

Creates a LogSpecBuilder, setting the default log level.

fn module_filters(&self) -> &Vec<ModuleFilter>

Provides a reference to the module filters.

fn text_filter(&self) -> &Option<Regex>

Provides a reference to the text filter.

Trait Implementations

impl Clone for LogSpecification

fn clone(&self) -> LogSpecification

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for LogSpecification

fn fmt(&self, __arg_0: &mut Formatter) -> Result

Formats the value using the given formatter.