use std::env;use std::fs;use std::fs::File;use std::io::Write;use std::path::PathBuf;use anyhow::Context;use anyhow::Result;use anyhow::anyhow;use anyhow::bail;fn main() -> Result<()> {    let mut args = env::args_os();    let _program = args.next();    let output_path = PathBuf::from(        args.next()            .ok_or_else(|| anyhow!("expected output path as first argument"))?,    );    let payload = args        .next()        .ok_or_else(|| anyhow!("expected payload as final argument"))?;    if args.next().is_some() {        bail!("expected payload as final argument");    }    let payload = payload.to_string_lossy();    let temp_path = PathBuf::from(format!("{}.tmp", output_path.display()));    let mut file = File::create(&temp_path)        .with_context(|| format!("failed to create {}", temp_path.display()))?;    file.write_all(payload.as_bytes())        .with_context(|| format!("failed to write {}", temp_path.display()))?;    file.sync_all()        .with_context(|| format!("failed to sync {}", temp_path.display()))?;    fs::rename(&temp_path, &output_path).with_context(|| {        format!(            "failed to move {} into {}",            temp_path.display(),            output_path.display()        )    })?;    Ok(())}