Struct env_logger::filter::Builder

pub struct Builder { /* fields omitted */ }

A builder for a log filter.

It can be used to parse a set of directives from a string before building a Filter instance.

Example

#[macro_use]
extern crate log;
extern crate env_logger;

use std::env;
use std::io;
use env_logger::filter::Builder;

fn main() {
    let mut builder = Builder::new();

    // Parse a logging filter from an environment variable.
    if let Ok(rust_log) = env::var("RUST_LOG") {
       builder.parse(&rust_log);
    }

    let filter = builder.build();
}

Methods

impl Builder

pub fn new() -> Builder

Initializes the filter builder with defaults.

pub fn from_env(env: &str) -> Builder

Initializes the filter builder from an environment.

pub fn filter_module(&mut self, module: &str, level: LevelFilter) -> &mut Self

Adds a directive to the filter for a specific module.

pub fn filter_level(&mut self, level: LevelFilter) -> &mut Self

Adds a directive to the filter for all modules.

pub fn filter(&mut self, module: Option<&str>, level: LevelFilter) -> &mut Self

Adds a directive to the filter.

The given module (if any) will log at most the specified level provided. If no module is provided then the filter will apply to all log messages.

pub fn parse(&mut self, filters: &str) -> &mut Self

Parses the directives string.

See the Enabling Logging section for more details.

pub fn build(&mut self) -> Filter

Build a log filter.

Trait Implementations

impl Default for Builder

fn default() -> Self

Returns the "default value" for a type.

impl Debug for Builder

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

Formats the value using the given formatter.