Crate cliw

Command line in web.

Clap in web.

Pronounced “Clue” as in “Get a cliw.”

Command line arguments for native and the web.
Also provide output for the web.

The goal is to be flexible, write your command line code once and it should be able to run anywhere!

Command Line Arguments

Provides a simple wrapper function args_os() that returns ArgsOs from std::env::args_os when running on native and UrlArgs when running on wasm. This is feature gated with the “urlargs” feature.

Output

Provides writers for output to the web when compiling to wasm and running in a browser. Also basic print(&str) and eprint(&str) functions that use the web or standard output depending on if compiled to native or wasm. On native, output is to standard output. On the web the output can be to the console, a pop-up alert, or standard output. Web output is feature gated with the “console”, “alert”, and “web-std-output” features.

Why use cliw?

You probably don’t want to use cliw directly. This crate was designed so clap can be used in the web. You normaly use cliw indirectly with a web enabled clap, we-clap which gives your web page clap powers. (opt parsing, help, suggestions, etc)

The README with recommended usage and screenshots is at crates.io, or the cliw repository. Also check out the docs and examples, specifically the we-clap_demo example.

Why not use cliw?

• If you are writing only for the web, you may not be wanting to use command line arguments.
• You might have another use of the url query string.
• You might be compiling to wasm but the framework you use provides std::env::args_os and/or standard output.

Example cliw_demo

As mentioned above, you probably want to use cliw indirectly, with we-clap but here is the obligitory cliw_demo example if you want to use just cliw.

Cargo.toml

 [package]
 name = "cliw_demo"
 version = "0.1.0"
 edition = "2021"

 [dependencies]
 cliw = { version = "0.1.0", features = [
     "alert",
     "urlargs",
 ]}

main.rs

fn main() {
    // Get the args from CLI on native
    // or the webpage URL on wasm in the browser
    let args = cliw::args_os();
    let args: Vec<_> = args.collect();
    let msg = format!("{:?}", args);
    // Output to standard on native
    // or web popup alert on wasm in the browser
    cliw::output::print(&msg);
}

Running on native.

$ cargo r -- arg1 arg2 ar3
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.02s
     Running `/path/to/target/debug/cliw_demo arg1 arg2 ar3`
["/path/to/target/debug/cliw_demo", "arg1", "arg2", "ar3"]

Running on the web with “alert” and “urlargs” features.

$ cargo r --target wasm32-unknown-unknown
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 10.44s
     Running `wasm-server-runner /path/to/target/wasm32-unknown-unknown/debug/cliw_demo.wasm`
 INFO wasm_server_runner: uncompressed wasm output is 189.62kb in size
 INFO wasm_server_runner: starting webserver at http://127.0.0.1:1334

Pointing your browser to

http://127.0.0.1:1334/?arg1&arg2&and&whatever

you would get a popup alert with the following text.

["http://127.0.0.1:1334/", "arg1", "arg2", "and", "whatever"]

Features

The functionality of the cliw crate is gated by features.

• “alert” : Enable output to browser popup alert.
• “console” : Enable output to browser console.
• “web-std-output” : Enable standard output on the web. You can use this if your web framework provides standard output. You always get standard output on native
• “urlargs” : Enable getting args from UrlArgs on the web. Do not use this if your web framework provides std::env::args_os.

For simplicity just set the “urlargs” and “console” or “alert” features in you Cargo.toml for both native and wasm. Under native you always get standard args and output.

cliw = { version = "0.1.0", features = [
    "alert",
    "urlargs",
]}

Modules

output

Output for the web

url_args

Slice a URL into command line arguments.

Functions

args_os

Return ArgsOs from env::args_os on native or UrlArgs on wasm