What is command-line-args?
The command-line-args npm package is a library for parsing command-line arguments in Node.js applications. It allows developers to define options and parse them from the command line, making it easier to handle user inputs and configurations.
What are command-line-args's main functionalities?
Basic Argument Parsing
This feature allows you to define and parse basic command-line arguments. In this example, the 'file' option expects a string value, and the 'verbose' option is a boolean flag.
const commandLineArgs = require('command-line-args');
const optionDefinitions = [
{ name: 'file', type: String },
{ name: 'verbose', type: Boolean }
];
const options = commandLineArgs(optionDefinitions);
console.log(options);
Default Values
This feature allows you to set default values for options. If the user does not provide a value for 'file' or 'verbose', the defaults 'default.txt' and 'false' will be used, respectively.
const commandLineArgs = require('command-line-args');
const optionDefinitions = [
{ name: 'file', type: String, defaultValue: 'default.txt' },
{ name: 'verbose', type: Boolean, defaultValue: false }
];
const options = commandLineArgs(optionDefinitions);
console.log(options);
Multiple Values
This feature allows you to handle multiple values for a single option. In this example, the 'files' option can accept multiple string values.
const commandLineArgs = require('command-line-args');
const optionDefinitions = [
{ name: 'files', type: String, multiple: true, defaultOption: true }
];
const options = commandLineArgs(optionDefinitions);
console.log(options);
Aliases
This feature allows you to define aliases for options. In this example, 'help' can be accessed with '-h' and 'version' with '-v'.
const commandLineArgs = require('command-line-args');
const optionDefinitions = [
{ name: 'help', alias: 'h', type: Boolean },
{ name: 'version', alias: 'v', type: Boolean }
];
const options = commandLineArgs(optionDefinitions);
console.log(options);
Other packages similar to command-line-args
yargs
Yargs is a popular library for parsing command-line arguments in Node.js. It provides a rich set of features, including command handling, argument validation, and automatic help generation. Compared to command-line-args, yargs offers more advanced features and a more user-friendly API.
commander
Commander is another widely-used library for building command-line interfaces in Node.js. It supports option parsing, command definitions, and automatic help generation. Commander is known for its simplicity and ease of use, making it a good alternative to command-line-args for simpler use cases.
minimist
Minimist is a lightweight library for parsing command-line arguments. It provides basic functionality for handling options and arguments, but lacks some of the advanced features found in command-line-args, yargs, and commander. Minimist is a good choice for projects that require minimal overhead.