8078400941
Add support for #44 (multiple values for positional arguments) when the positional argument is the last one (i.e. highest index) |
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claptests | ||
docs | ||
examples | ||
src | ||
.gitignore | ||
.travis.yml | ||
Cargo.toml | ||
CHANGELOG | ||
index.html | ||
LICENSE-MIT | ||
Makefile | ||
README.md |
clap
Command Line Argument Parser written in Rust
It is a simple to use and efficient library for parsing command line arguments and subcommands when writing command line, console, or terminal applications.
You can use clap to lay out a list of possible valid command line arguments and subcommands, then let clap
parse and validate the string given by the user at runtime. This means you focus on your applications functionality, not parsing and validating arguments.
What seperates clap
from other options available is the very simple almost 'Pythonic' style in which you define the valid available arguments for your program. This means you don't have to spend tons time learning an entirely new library's structures and use.
clap
also provides all the traditional version and help switches (or flags) 'for free' by parsing the list of developer supplied arguments. If the developer hasn't defined them already, clap
will auto-generate only the applicable "help" and "version" switches (as well as a "help" subcommand so long as other subcommands have been manually defined as well).
After defining a list of possible valid arguments and subcommands, clap
parses the string given by the end-user at runtime then gives you a list of the valid matches and their values. If the user made an error or typo, clap
informs them and exits gracefully. This means that you can simply use these matches and values to determine the functioning of your program.
Quick Example
// (Full example with comments in examples/01_QuickExample.rs)
extern crate clap;
use clap::{Arg, App, SubCommand};
fn main() {
let matches = App::new("MyApp")
.version("1.0")
.author("Kevin K. <kbknapp@gmail.com>")
.about("Does awesome things")
.arg(Arg::new("CONFIG")
.short("c")
.long("config")
.help("Sets a custom config file")
.takes_value(true))
.arg(Arg::new("output")
.help("Sets an optional output file")
.index(1))
.arg(Arg::new("debug")
.short("d")
.multiple(true)
.help("Turn debugging information on"))
.subcommand(SubCommand::new("test")
.about("controls testing features")
.arg(Arg::new("verbose")
.short("v")
.help("print test information verbosely")))
.get_matches();
if let Some(o) = matches.value_of("output") {
println!("Value for output: {}", o);
}
if let Some(c) = matches.value_of("CONFIG") {
println!("Value for config: {}", c);
}
match matches.occurrences_of("debug") {
0 => println!("Debug mode is off"),
1 => println!("Debug mode is kind of on"),
2 => println!("Debug mode is on"),
3 | _ => println!("Don't be crazy"),
}
if let Some(ref matches) = matches.subcommand_matches("test") {
if matches.is_present("verbose") {
println!("Printing verbosely...");
} else {
println!("Printing normally...");
}
}
// more porgram logic goes here...
}
If you were to compile the above program and run it with the flag --help
or -h
(or help
subcommand, since we defined test
as a subcommand) the following output woud be presented
$ myprog --help
MyApp 1.0
Kevin K. <kbknapp@gmail.com>
Does awesome things
USAGE:
MyApp [FLAGS] [OPTIONS] [POSITIONAL] [SUBCOMMANDS]
FLAGS:
-d Turn debugging information on
-h,--help Prints this message
-v,--version Prints version information
OPTIONS:
-c,--config=CONFIG Sets a custom config file
POSITIONAL ARGUMENTS:
output Sets an optional output file
SUBCOMMANDS:
help Prints this message
test Controls testing features
Installation
Add clap
as a dependecy in your Cargo.toml
file to use from crates.io:
[dependencies]
clap = "*"
Or track the latest on the master branch at github:
[dependencies.clap]
git = "https://github.com/kbknapp/clap-rs.git"
Then run cargo build
or cargo update
for your project.
Usage
Add extern crate clap;
to your crate root.
More Information
You can find complete documentation on the github-pages site for this project.
You can also find full usage examples in the examples/ directory of this repo.
How to build
Clone the repo (master
branch if using clap
, dev
branch if contributing) and build with Cargo
git clone https://github.com/kbknapp/clap-rs
cd clap-rs
cargo build --release
Running the tests
If contributing, you can run the tests as follows (assuming you've already cloned the repo to clap-rs/
cd clap-rs/claptests
make test
Building the documentation
Run this instead of cargo doc
to generate the proper module docstring:
make doc
Then browse to clap-rs/docs/index.html
in your web-browser of choice