Struct env_logger::fmt::Formatter[][src]

pub struct Formatter {
    buf: Rc<RefCell<Buffer>>,
    write_style: WriteStyle,
}
Expand description

A formatter to write logs into.

Formatter implements the standard Write trait for writing log records. It also supports terminal colors, through the style method.

Examples

Use the writeln macro to format a log record. An instance of a Formatter is passed to an env_logger format as buf:

use std::io::Write;

let mut builder = env_logger::Builder::new();

builder.format(|buf, record| writeln!(buf, "{}: {}", record.level(), record.args()));

Fields

buf: Rc<RefCell<Buffer>>write_style: WriteStyle

Implementations

Get a Timestamp for the current date and time in UTC.

Examples

Include the current timestamp with the log record:

use std::io::Write;

let mut builder = env_logger::Builder::new();

builder.format(|buf, record| {
    let ts = buf.timestamp();

    writeln!(buf, "{}: {}: {}", ts, record.level(), record.args())
});

Get a Timestamp for the current date and time in UTC with full second precision.

Get a Timestamp for the current date and time in UTC with millisecond precision.

Get a Timestamp for the current date and time in UTC with microsecond precision.

Get a Timestamp for the current date and time in UTC with nanosecond precision.

Begin a new Style.

Examples

Create a bold, red colored style and use it to print the log level:

use std::io::Write;
use env_logger::fmt::Color;

let mut builder = env_logger::Builder::new();

builder.format(|buf, record| {
    let mut level_style = buf.style();

    level_style.set_color(Color::Red).set_bold(true);

    writeln!(buf, "{}: {}",
        level_style.value(record.level()),
        record.args())
});

Get the default Style for the given level.

The style can be used to print other values besides the level.

Get a printable Style for the given level.

The style can only be used to print the level.

Trait Implementations

Formats the value using the given formatter. Read more

Write a buffer into this writer, returning how many bytes were written. Read more

Flush this output stream, ensuring that all intermediately buffered contents reach their destination. Read more

Like write, except that it writes from a slice of buffers. Read more

🔬 This is a nightly-only experimental API. (can_vector)

Determines if this Writer has an efficient write_vectored implementation. Read more

Attempts to write an entire buffer into this writer. Read more

🔬 This is a nightly-only experimental API. (write_all_vectored)

Attempts to write multiple buffers into this writer. Read more

Writes a formatted string into this writer, returning any error encountered. Read more

Creates a “by reference” adapter for this instance of Write. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Performs the conversion.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.