clap-stdin 0.7.0

Provides a type for easily accepting Clap arguments from stdin
Documentation 
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#![allow(dead_code)]

//! An example CLI that uses `FileOrStdin` for a serde_json deserializable value
//! from a file or stdin
//!
//! Example usage:
//! ```sh
//! # via stdin
//! $ echo '{ "name": "Trinity", "age": 30 }' | cargo run --example parse_with_serde
//!
//! # via file read
//! $ cat contents.json
//! '{ "name": "Trinity", "age": 30 }'
//! $ cargo run --example parse_with_serde -- ./contents.json
//!
//! # Using tokio AsyncRead
//! $ cargo run --features tokio --example parse_with_serde -- ./contents.json
//! ```
use std::str::FromStr;

use clap::Parser;
use clap_stdin::FileOrStdin;
use serde::Deserialize;

#[derive(Clone, Debug, Deserialize)]
struct User {
    name: String,
    age: u8,
}

impl FromStr for User {
    type Err = serde_json::Error;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        serde_json::from_str(s)
    }
}

#[derive(Debug, Parser)]
struct Args {
    /// Parsed user from json, provided via a filepath (or leave blank to read from stdin)
    #[arg(default_value = "-")]
    user: FileOrStdin<User>,
}

#[cfg(not(feature = "tokio"))]
fn main() -> anyhow::Result<()> {
    let args = Args::parse();
    eprintln!("{:?}", args.user.contents()?);
    Ok(())
}

#[cfg(feature = "tokio")]
#[tokio::main(flavor = "current_thread")]
async fn main() -> anyhow::Result<()> {
    let args = Args::parse();
    eprintln!("{:?}", args.user.contents_async().await?);
    Ok(())
}