Struct env_logger::Logger

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pub struct Logger { /* private fields */ }
Expand description

The env logger.

This struct implements the Log trait from the log crate, which allows it to act as a logger.

The init(), try_init(), Builder::init() and Builder::try_init() methods will each construct a Logger and immediately initialize it as the default global logger.

If you’d instead need access to the constructed Logger, you can use the associated Builder and install it with the log crate directly.

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impl Logger

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pub fn from_env<'a, E>(env: E) -> Selfwhere E: Into<Env<'a>>,

Creates the logger from the environment.

The variables used to read configuration from can be tweaked before passing in.

Examples

Create a logger reading the log filter from an environment variable called MY_LOG:

use env_logger::Logger;

let logger = Logger::from_env("MY_LOG");

Create a logger using the MY_LOG variable for filtering and MY_LOG_STYLE for whether or not to write styles:

use env_logger::{Logger, Env};

let env = Env::new().filter_or("MY_LOG", "info").write_style_or("MY_LOG_STYLE", "always");

let logger = Logger::from_env(env);
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pub fn from_default_env() -> Self

Creates the logger from the environment using default variable names.

This method is a convenient way to call from_env(Env::default()) without having to use the Env type explicitly. The logger will use the default environment variables.

Examples

Creates a logger using the default environment variables:

use env_logger::Logger;

let logger = Logger::from_default_env();
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pub fn filter(&self) -> LevelFilter

Returns the maximum LevelFilter that this env logger instance is configured to output.

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pub fn matches(&self, record: &Record<'_>) -> bool

Checks if this record matches the configured filter.

Trait Implementations§

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impl Debug for Logger

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

Formats the value using the given formatter. Read more
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impl Log for Logger

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fn enabled(&self, metadata: &Metadata<'_>) -> bool

Determines if a log message with the specified metadata would be logged. Read more
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fn log(&self, record: &Record<'_>)

Logs the Record. Read more
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fn flush(&self)

Flushes any buffered records.

Auto Trait Implementations§

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impl !RefUnwindSafe for Logger

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impl Send for Logger

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impl Sync for Logger

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impl Unpin for Logger

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impl !UnwindSafe for Logger

Blanket Implementations§

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impl<T> Any for Twhere T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for Twhere T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for Twhere T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for Twhere U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T, U> TryFrom<U> for Twhere U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.