web5design / cli

Rapidly build command line apps with node

cli is a toolkit for rapidly building command line apps - it includes:

• Full featured opts/args parser
• Plugin support for adding common options and switches
• Helper methods for working with input/output and spawning child processes
• Output colored/styled messages, progress bars or spinners
• Command auto-completion and glob support

Install using npm install cli or just bundle cli.js with your app.

Example apps

sort.js

#!/usr/bin/env node
require('cli').withStdinLines(function(lines, newline) {
    this.output(lines.sort().join(newline));
});

Try it out

$ ./sort.js < input.txt

Let's add support for an -n switch to use a numeric sort, and a -r switch to reverse output - only 5 extra lines of code (!)

var cli = require('cli'), options = cli.parse();

cli.withStdinLines(function(lines, newline) {
    lines.sort(!options.n ? null : function(a, b) {
        return parseInt(a) > parseInt(b);
    });
    if (options.r) lines.reverse();
    this.output(lines.join(newline));
});

static.js

Let's create a static file server with daemon support to see the opts parser + plugins in use - note: this requires npm install creationix daemon

var cli = require('cli').enable('daemon', 'status'); //Enable 2 plugins

cli.parse({
    log:   ['l', 'Enable logging'],
    port:  ['p', 'Listen on this port', 'number', 8080],
    serve: [false, 'Serve static files from PATH', 'path', './public']
});

cli.main(function(args, options) {
    var server, middleware = [];

    if (options.log) {
        this.debug('Enabling logging');
        middleware.push(require('creationix/log')());
    }

    this.debug('Serving files from ' + options.serve);
    middleware.push(require('creationix/static')('/', options.serve, 'index.html'));

    server = this.createServer(middleware).listen(options.port);

    this.ok('Listening on port ' + options.port);
});

To output usage information

$ ./static.js --help

To create a daemon that serves files from /tmp, run

$ ./static.js -ld --serve=/tmp

For more examples, see ./examples

Helper methods

cli has methods that collect stdin (newline is autodetected as \n or \r\n)

cli.withStdin(callback);        //callback receives stdin as a string
cli.withStdinLines(callback);   //callback receives stdin split into an array of lines (lines, newline)

cli also has a lower level method for working with input line by line (see ./examples/cat.js for an example).

cli.withInput(file, function (line, newline, eof) {
    if (!eof) {
        this.output(line + newline);
    }
});

Note: file can be omitted if you want to work with stdin

To output a progress bar, call

cli.progress(progress); //Where 0 <= progress <= 1

To spawn a child process, use

cli.exec(cmd, callback); //callback receives the output of the process (split into lines)

cli also comes bundled with kof's node-natives (access with cli.native) and creationix' stack (access with cli.createServer)

Plugins

Plugins are a way of adding common opts and can be enabled using

cli.enable(plugin1, [plugin2, ...]);  //To disable, use the equivalent disable() method

help - enabled by default

Adds -h,--help to output auto-generated usage information

version

Adds -v,--version to output version information for the app. cli will attempt to locate and parse a nearby package.json

To set your own app name and version, use cli.setApp(app_name, version)

status

Adds options to show/hide the stylized status messages that are output to the console when using one of these methods

cli.debug(msg);  //Only shown when using --debug
cli.error(msg);
cli.fatal(msg);  //Exits the process after outputting msg
cli.info(msg);
cli.ok(msg);

-k,--no-color will omit ANSI color escapes from the output

glob - requires npm install glob

Enables glob matching of arguments

daemon - requires npm install daemon

Adds -d,--daemon ARG for daemonizing the process and controlling the resulting daemon

ARG can be either start (default), stop, restart, pid (outputs the daemon's pid if it's running), or log (output the daemon's stdout+stderr)

timeout

Adds -t,--timeout N to exit the process after N seconds with an error

catchall

Adds -c,--catch to catch and output uncaughtExceptions and resume execution

Note: Plugins are automatically disabled if an option or switch of the same name is already defined

LICENSE

(MIT license)

Copyright (c) 2010 Chris O'Hara [email protected]

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.