Crate clap_file

Provides types for clap’s derive interface, enabling easy handling of input/output with automatically opened files or standard input/output based on command-line arguments.

Usage

Run cargo add clap-file or add this to your Cargo.toml:

[dependencies]
clap-file = "0.2.0"

Examples

Example usage of Input ans Output types:

use std::io::{self, BufRead as _, Write as _};

use clap::Parser as _;
use clap_file::{Input, Output};

#[derive(Debug, clap::Parser)]
struct Args {
    /// Input file. If not provided, reads from standard input.
    input: Input,
    /// output file. If not provided, reads from standard output.
    output: Output,
}

fn main() -> io::Result<()> {
    let args = Args::parse();
    let input = args.input.lock();
    let mut output = args.output.lock();
    for line in input.lines() {
        let line = line?;
        writeln!(&mut output, "{line}")?;
    }
    Ok(())
}

Structs

Input

Represents an input source, which can be either standard input or a file.

LockedInput

A locked input source that implements Read and BufRead traits.

LockedOutput

A locked output sink that can be written to.

Output

Represents an output sink, which can be either standard output or a file.