cli-distribution

CLI Distribution Skill

Patterns and best practices for distributing Rust CLI applications to users.

Shell Completion Generation

Using clap_complete

use clap::{CommandFactory, Parser};
use clap_complete::{generate, Generator, Shell};
use std::io;

#[derive(Parser)]
struct Cli {
    /// Generate shell completions
    #[arg(long = "generate", value_enum)]
    generator: Option<Shell>,

    // ... other fields
}

fn print_completions<G: Generator>(gen: G, cmd: &mut clap::Command) {
    generate(gen, cmd, cmd.get_name().to_string(), &mut io::stdout());
}

fn main() {
    let cli = Cli::parse();

    if let Some(generator) = cli.generator {
        let mut cmd = Cli::command();
        print_completions(generator, &mut cmd);
        return;
    }

    // ... rest of application
}

Installation Instructions by Shell

Bash:

# Generate and save
myapp --generate bash > /etc/bash_completion.d/myapp

# Or add to ~/.bashrc
eval "$(myapp --generate bash)"

Zsh:

# Generate and save
myapp --generate zsh > ~/.zfunc/_myapp

# Add to ~/.zshrc
fpath=(~/.zfunc $fpath)
autoload -Uz compinit && compinit

Fish:

# Generate and save
myapp --generate fish > ~/.config/fish/completions/myapp.fish

# Or load directly
myapp --generate fish | source

PowerShell:

# Add to $PROFILE
Invoke-Expression (& myapp --generate powershell)

Dynamic Completions

For commands with dynamic values (like listing resources):

use clap::CommandFactory;
use clap_complete::{generate, Generator};

pub fn generate_with_values<G: Generator>(
    gen: G,
    resources: &[String],
) -> String {
    let mut cmd = Cli::command();

    // Add dynamic values to completion
    if let Some(subcommand) = cmd.find_subcommand_mut("get") {
        for resource in resources {
            subcommand = subcommand.arg(
                clap::Arg::new("resource")
                    .value_parser(clap::builder::PossibleValuesParser::new(resource))
            );
        }
    }

    let mut buf = Vec::new();
    generate(gen, &mut cmd, "myapp", &mut buf);
    String::from_utf8(buf).unwrap()
}