# argwerk
[](https://docs.rs/argwerk)
[](https://crates.io/crates/argwerk)
[](https://github.com/udoprog/argwerk/actions)
Helper utility for parsing simple commandline arguments.
This is **not** intended to be a complete commandline parser library.
Instead this can be used as an alternative quick-and-dirty approach that can
be cheaply incorporated into a tool.
We provide:
* A dependency-free commandline parsing framework using declarative macros.
So it's hopefully lightweight and compiles quickly.
* A flexible mechanism for parsing.
* Formatting decent looking help messages.
We specifically do not support:
* As-close-to correct line wrapping with wide unicode characters as possible
(see [textwrap]).
* Required arguments. If your argument is required, you'll have to
[ok_or_else] it yourself from an `Option<T>`.
* Complex command structures like subcommands.
For a more complete commandline parsing library, use [clap].
See the documentation for [argwerk::parse!] for how to use.
## Examples
> This is available as a runnable example:
> ```sh
> cargo run --example tour
> ```
```rust
let args = argwerk::parse! {
/// A simple test command.
///
/// This is nice!
"command [-h]" {
help: bool,
file: Option<String>,
input: Option<String>,
limit: usize = 42,
positional: Option<(String, Option<String>)>,
rest: Vec<String>,
}
/// Prints the help.
///
/// This includes:
/// * All the available switches.
/// * All the available positional arguments.
/// * Whatever else the developer decided to put in here! We even support wrapping comments which are overly long.
"-h" | "--help" => {
help = true;
print_help();
Ok(())
}
/// Limit the number of things by <n>.
"--limit" | "-l", n => {
limit = str::parse(&n)?;
Ok(())
}
/// Write to the file specified by <path>.
"--file", path if !file.is_some() => {
file = Some(path);
Ok(())
}
/// Read from the specified input.
"--input", #[option] path => {
input = path;
Ok(())
}
/// Takes argument at <foo> and <bar>.
///
/// * This is an indented message. The first alphanumeric character determines the indentation to use.
(foo, #[option] bar, #[rest] args) if positional.is_none() => {
positional = Some((foo, bar));
rest = args;
Ok(())
}
}?;
dbg!(args);
```
[ok_or_else]: https://doc.rust-lang.org/std/option/enum.Option.html#method.ok_or_else
[textwrap]: https://docs.rs/textwrap/0.13.2/textwrap/#displayed-width-vs-byte-size
[argwerk::parse!]: https://docs.rs/argwerk/0/argwerk/macro.parse.html
[clap]: https://docs.rs/clap
License: MIT/Apache-2.0