README.md

clifw

Yet another ultra lightweight CLI framework for parsing command line arguments passed to programs.
The API also allows you to build an interactive shell.

Example

The main public API CLI allows you to build a schema for the expected arguments.
This is a convenient solution that offers a modern, descriptive and fluent manner.

public static void main(String[] args) {
    CLI cli = CLI.setArgs(args) // args = new String[] { "-a" }
        .addOpt(Opt
            .useChar('a')
            .description("this is a short test option")
            .build())
        .build();
    ...
}

Once you've defined the schema, call the run method and let the framework do it's job.

try {
    cli.run();
    ...
} catch(Exception e) {
    System.err.println(e.getMessage());
}

The last step is to process the result cli.getResult() in your own business code.
For an example of an interactive shell, read the shell documentation.

General Design

The main building block is the schema which consists of different other sub building blocks and glue components.

Schema

Name	Pattern	Examples	Description
Options	[-<o>|--<option>]...	-r --recursive -o=filename -i name	This schema allows to define an arbitrary sequence of options. An option is either a single character with a preceding - or any word with a preceding --. An optional value can be assigned, either in the mathematical notation with the = sign or simply separated by a space. Obviously, further restrictions on the value must be made, for example it must not start with a dash or contain spaces.
Arguments	[<arg>]...	1 2 3 "My Name"	Numbers or words can be used as arguments. If a single argument contains spaces, it must be enclosed in quotation marks.
Options and arguments	[-<o>|--<option>]... [<arg>]...	-c 3 output.txt	The order is important here, the first argument may only come after the last option including its value, if any.
Commands	<command> [-<o>|--<option>]... [<arg>]...	checkout -b development	Note that at most one command can be passed as an argument per call. However, any number of different commands can of course be defined in the API.
Shell			Behaves like if you put the Commands scheme in a loop. Before entering the interactive shell, the Options and arguments schema applies.

The setArgs and useShell methods initiate the declarative definition of the schema. In the first method, a schema can be passed as an optional argument, the default value corresponds to "Options". However, a builder object is returned, which is also implemented as a fluent interface. See API section for more details.