3 unstable releases

Uses old Rust 2015

0.2.0 Dec 2, 2017
0.1.1 Dec 1, 2017
0.1.0 Nov 30, 2017

#38 in #cmd

26 downloads per month
Used in kubeauth

WTFPL license

8KB
60 lines

Command line parser for rust (clpr)

A bare-bones rust command line parser.

Dependencies

This project has no external dependencies

What's new

The most recent version (0.2.0) contains the following:

  • The return value is now a Vector
  • Under the hood improvements

Usage

Add the crate to your Cargo.toml file and you can use it to parse incoming arguments and flags.

cmdparser = "0.2.0"

And in the file that will consume the crate:

extern crate cmdparser;

Parse incoming arguments and flags by calling "parse()" and receiving a touple.

let (arguments, flags) = Parser::new().parse();

First element of the touple is a HashMap<String, Vec> that contains all of the key value arguments received from the command line. By default, "-" and "--" prefixes are parsed and accepted.

If the user supplies multiple arguments under different positions they will be overwritten by default. To disable this behavior use

merge_values(bool)

When merge_values is set to true under a parser instance, and the user passes the following arguments

$ ./executable -i foo.jpg -i bar.jpg

The parser will merge "foo.jpg" and "bar.jpg" values under the "i" argument. If merge_values is set to false (which is the default behavior) the "i" argument will hold a single value of "bar.jpg".

If you want to limit the user to a certain prefix(es) use the strict_prefix(prefixes: Vec<String>) method.

let prefixes = vec!["~".to_owned()];
let (arguments, flags) = Parser::new().strict_prefix(prefixes).parse();

The created parser will only accept arguments prefixed with a tilda (~) character.

Example

Running your program with the following arguments:

$ cargo run -- -i foo.jpg bar.png -zero true -flag -param 100 -o
OR
$ ./executable -i foo.jpg -o bar.txt -p -r 10 -t -z -l 100

Yields the following:

ArgumentList: {"param": ["100"], "zero": ["true"], "i": ["foo.jpg", "bar.png"]}
Flags: ["flag", "o"]

To consume them the simplest patterns would be, for an argument:

let images: Vec<String>= arguments.get("i").or(arguments.get("images")).expect("No image argument provided");

For a flag:

if flags.contains(&"opaque".to_owned()) || flags.contains(&"o".to_owned()) {
    action();
};

The given code would look for -images or -i and in case they're not found panic with the erro message.

Comparison to clap-rs

While clap is a robust, feature rich and tested package, it has 886 reverse dependencies and it's simply an overkill for most usages.

Performance

The parser will parse 100 flags and 100 single value arguments in ~1ms on a 4c4t i5.

Contributing

As this is a very basic parser, and I don't have a lot of Rust experience, if you want to contribute and improve something, submit a pull request.

Contributors

Nenad Lukic - lnenad

License

WTFPL

No runtime deps