Provide shell completions

[Freed-Wu]

can we have token --<TAB> to complete options? Perhaps https://docs.rs/clap_complete/latest/clap_complete/ can be helpful.

[ther12k]

Yes, clap_complete is the right tool for this. Tokei already uses clap 4 (verified in Cargo.toml: clap = { version = "4", optional = true, features = ["cargo", "string", "wrap_help"] }), and clap 4 has first-class completion support via clap_complete.

A minimal implementation:

# Cargo.toml — add under [features]/[dependencies]
clap_complete = { version = "4", optional = true }

[features]
cli = ["dep:clap", "dep:colored", "dep:env_logger", "dep:num-format", "dep:clap_complete"]

// In the binary that builds the clap Command (src/bin/tokei.rs or similar)
use clap_complete::{generate, Shell};

fn print_completions(shell: Shell) {
    let mut cmd = tokei::cli::build_cli(); // your clap::Command
    let bin_name = "tokei";
    generate(shell, &mut cmd, bin_name, &mut std::io::stdout());
}

Add a hidden CLI flag like --generate-completion <shell> (where <shell> is one of bash, zsh, fish, elvish, powershell) that calls print_completions. Users then redirect stdout to the appropriate path:

tokei --generate-completion bash   > /etc/bash_completion.d/tokei
tokei --generate-completion fish   > ~/.config/fish/completions/tokei.fish
tokei --generate-completion zsh    > "${fpath[1]}/_tokei"

Two practical notes:

1. Keep clap_complete behind the existing cli feature flag so completions only get pulled in when clap itself is built.
2. If you'd rather ship static completions in the release tarball (no runtime generation), clap_complete also offers generate_to for build.rs — but the runtime flag approach is simpler and avoids per-shell build artifacts.

Happy to send a PR if useful.

[ther12k]

Self-correction after re-reading the source. I went back to verify the symbol names I used and my code snippet is wrong on one detail — there's no tokei::cli::build_cli(). src/cli.rs builds the clap Command inline inside Cli::from_args() and discards it after parsing into ArgMatches, so it's not exposed publicly.

The actual implementation needs a small refactor first: extract the Command builder into a pub fn cli_command() -> clap::Command in src/cli.rs, call it from Cli::from_args(), and call it again from the new completion flag. Concrete shape:

// src/cli.rs
pub fn cli_command() -> clap::Command {
    clap::Command::new("tokei")
        .version(crate_version())
        .author("Erin P. <xampprocky@gmail.com> + Contributors")
        .styles(clap_cargo::style::CLAP_STYLING)
        .about(concat!(crate_description!(), "
", "Support this project on GitHub Sponsors: https://github.com/sponsors/XAMPPRocky"))
        .arg(/* columns */)
        // ... all existing args
        .arg(
            Arg::new("generate-completion")
                .long("generate-completion")
                .value_parser(value_parser!(Shell))
                .value_name("SHELL")
                .hide(true),
        )
}

impl Cli {
    pub fn from_args() -> Self {
        let mut cmd = cli_command();
        let matches = cmd.clone().get_matches();
        if let Ok(shell) = matches.get_one::<Shell>("generate-completion") {
            let bin = std::env::args().next().unwrap_or_else(|| "tokei".into());
            clap_complete::generate(*shell, &mut cmd, bin, &mut std::io::stdout());
            std::process::exit(0);
        }
        // ...rest unchanged
    }
}

The clap_complete = "4" dep and cli = ["dep:clap_complete"] feature gate I described before still apply. Sorry for the bad snippet in the first reply — happy to send a PR if useful.

[Freed-Wu]

Can you provide a PR? TIA!