Make Layer::with_writer not truncate the file

[wiiznokes]

Feature Request

Motivation

I might be wrong, but i think tracing automatically truncate the file given to Layer::with_writer

Proposal

I would like to not truncate the file

[mladedav]

How are you creating the writer/file? tracing just tries to write to anything you give to it.

[wiiznokes]

This is the full function

fn init_logging(cmd: &str) {
    use tracing_subscriber::{fmt, Registry};

    let logdir = match dirs::state_dir() {
        Some(dir) => dir.join("pop-launcher/"),
        None => dirs::home_dir()
            .expect("home directory required")
            .join(".cache/pop-launcher"),
    };

    let _ = std::fs::create_dir_all(&logdir);

    let logfile = std::fs::OpenOptions::new()
        .create(true)
        .truncate(false)
        .write(true)
        .open(logdir.join([cmd, ".log"].concat().as_str()).as_path());

    if let Ok(file) = logfile {

        let filter_layer = EnvFilter::try_from_default_env()
            .or_else(|_| EnvFilter::try_new("debug"))
            .unwrap();

        let fmt_layer = fmt::layer()
            .with_target(false)
            .with_timer(fmt::time::ChronoLocal::new("%T".into()))
            .with_writer(file);

        let subscriber = Registry::default().with(filter_layer).with(fmt_layer);

        tracing::subscriber::set_global_default(subscriber).expect("Failed to set subscriber");
    }
}

each time this function is run, the file get override

[mladedav]

You should use append instead of write. Please see the relevant docs but the short story is with this configuration the file is not truncated, but the writing starts at the start of the file and overwrites previous contents.

[wiiznokes]

Indeed, thanks