#cli #completion #autocomplete


Write shell completion scripts in pure Rust

2 releases

0.0.2 Jan 5, 2023
0.0.1 May 19, 2019

#6 in #autocomplete


185 lines

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Shell completions, which provide auto-complete for CLI applications, are typically written in Bash. This crate provides low level primitives for writing shell completion scripts in Rust.


Shell completion scripts are written as normal Rust binaries. A minimal example is below:

use shell_completion::{BashCompletionInput, CompletionInput, CompletionSet};

fn main() {
    let input = BashCompletionInput::from_env()
        .expect("Missing expected environment variables");

    let completions = input.complete_subcommand(vec!["add", "commit"]);


A more advanced example is available in the cargo_completion crate within this workspace. To try it out, run cargo install --force --path cargo_completion/ && complete -C _cargo_completion cargo, then type cargo run --<TAB> in the same shell.

The complete command registered our shell completion script for cargo. Note that complete commands do not persist (they are only active in the shell where you run complete), so if you want to use a completion long term you'll want to add the complete command to your ~/.bash_profile.

See this blog post for more details.


This crate is not quite ready for production use, but if you are an early adopter, feel free to make a PR adding yourself to the list below.

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Licensed under either of

at your option.


All forms of contribution are valued. I've created issues for many high level topics of exploration, and any feedback there will be very helpful in moving this crate in the right direction. Of course, code contributions are appreciated as well.

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

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