npm package: @gerhobbelt/nomnom
Description: Option parser with generated usage and commands
Author: Heather Arthur
Latest version: 1.8.4-31

> 
> # deprecation notice for original
> 
> The original author's `nomnom` is deprecated; this fork is not: we continue to update this library.
> 
> When you are unsure about using this library's fork (or others), you may wish to check out https://github.com/tj/commander.js.
>
> Personally, I prefer using `nomnom` over `commander` or other option parsers, so I will keep this one. :-)
> 

# nomnom


[![build status](https://secure.travis-ci.org/GerHobbelt/nomnom.png)](https://travis-ci.org/search/nomnom)


nomnom is an option parser for node. It noms your args and gives them back to you in a hash.

```javascript
var opts = require("@gerhobbelt/nomnom")
   .option('debug', {
      abbr: 'd',
      flag: true,
      help: 'Print debugging info'
   })
   .option('config', {
      abbr: 'c',
      default: 'config.json',
      help: 'JSON file with tests to run'
   })
   .option('version', {
      flag: true,
      help: 'print version and exit',
      callback: function() {
         return "version 1.2.4";
      }
   })
   .parse();

if (opts.debug)
   // do stuff
```

You don't have to specify anything if you don't want to:

```javascript
var opts = require("@gerhobbelt/nomnom").parse();

var url = opts[0];     // get the first positional arg
var file = opts.file   // see if --file was specified
var verbose = opts.v   // see if -v was specified
var extras = opts._    // get an array of the unmatched, positional args
```


# Install

for [node.js](http://nodejs.org/) and [npm](http://github.com/isaacs/npm):

	npm install @gerhobbelt/nomnom


# More Details

Nomnom supports args like `-d`, `--debug`, `--no-debug`, `--file=test.txt`, `--file test.txt`, `-f test.txt`, `-xvf`, and positionals. Positionals are arguments that don't fit the `-a` or `--atomic` format and aren't attached to an option.

Values are JSON parsed, so `--debug=true --count=3 --file=log.txt` would give you:

```
{
   "debug": true,
   "count": 3,
   "file": "log.txt"
}
```


# Commands

Nomnom supports command-based interfaces (e.g. with git: `git add -p` and `git rebase -i` where `add` and `rebase` are the commands):

```javascript
var parser = require("@gerhobbelt/nomnom");

parser.command('browser')
   .callback(function(opts, command) {
      runBrowser(opts.url);
   })
   .help("run browser tests");

parser.command('sanity')
   .option('outfile', {
      abbr: 'o',
      help: "file to write results to"
   })
   .option('config', {
      abbr: 'c',
      default: 'config.json',
      help: "json manifest of tests to run"
   })
   .callback(function(opts, command) {
      runSanity(opts.filename);
   })
   .help("run the sanity tests")

parser.parse();
```

Each command generates its own usage message when `-h` or `--help` is specified with the command.


# Usage

Nomnom prints out a usage message if `--help` or `-h` is an argument. If no commands are called (the script is simply run without arguments), `-h` will be called automatically unless you've disabled this feature using the `.autoShowUsage(false)` API call. 

Usage for these options in `test.js`:

```javascript
var opts = require("@gerhobbelt/nomnom")
   .script("runtests")
   .options({
      path: {
         position: 0,
         help: "Test file to run",
         list: true
      },
      config: {
         abbr: 'c',
         metavar: 'FILE',
         help: "Config file with tests to run"
      },
      debug: {
         abbr: 'd',
         flag: true,
         help: "Print debugging info"
      }
   }).parse();
```

...would look like this:

	usage: runtests <path>... [options]

	path     Test file to run

	options:
	   -c FILE, --config FILE   Config file with tests to run
	   -d, --debug              Print debugging info


# Options

You can either add a specification for an option with `nomnom.option('name', spec)` or pass the specifications to `nomnom.options()` as a hash keyed on option name. Each option specification can have the following fields:


#### abbr and full

`abbr` is the single character string to match to this option, `full` is the full-length string (defaults to the name of the option).

This option matches `-d` and `--debug` on the command line:

```javascript
nomnom.option('debug', {
   abbr: 'd'
})
```

This option matches `-n 3`, `--num-lines 12` on the command line:

```javascript
nomnom.option('numLines', {
   abbr: 'n',
   full: 'num-lines'
})
```


#### flag

If this is set to true, the option acts as a flag and doesn't swallow the next value on the command line. Default is `false`, so normally if you had a command line `--config test.js`, `config` would get a value of `test.js` in the options hash. Whereas if you specify:

```javascript
nomnom.option('config', {
   flag: true
})
```

`config` would get a value of `true` in the options hash, and `test.js` would be a free positional arg.


#### metavar

`metavar` is used in the usage printout e.g. `"PATH"` in `"-f PATH, --file PATH"`.


#### string

A shorthand for `abbr`, `full`, and `metavar`. For example, to attach an option to `-c` and `--config` use a `string: "-c FILE, --config=FILE"`


#### help

A string description of the option for the usage printout.


#### default

The value to give the option if it's not specified in the arguments.


#### type

If you don't want the option JSON-parsed, specify type `"string"`.


#### callback

A callback that will be executed as soon as the option is encountered. If the callback returns a string it will print the string and exit:

```javascript
nomnom.option('count', {
   callback: function(count) {
      if (count != parseInt(count)) {
         return "count must be an integer";
      }
   }
})
```


#### position

The position of the option if it's a positional argument. If the option should be matched to the first positional arg use position `0`, etc.


#### list

Specifies that the option is a list. Appending can be achieved by specifying the arg more than once on the command line:

	node test.js --file=test1.js --file=test2.js

If the option has a `position` and `list` is `true`, all positional args including and after `position` will be appended to the array.


#### required

If this is set to `true` and the option isn't in the args, a message will be printed and the program will exit.


#### choices

A list of the possible values for the option (e.g. `['run', 'test', 'open']`). If the parsed value isn't in the list a message will be printed and the program will exit.


#### transform

A function that takes the value of the option as entered and returns a new value that will be seen as the value of the option.

```javascript
nomnom.option('date', {
   abbr: 'd',
   transform: function(timestamp) {
     return new Date(timestamp);
   }
})
```


#### hidden

Option won't be printed in the usage


# Parser interface

`require("nomnom")` will give you the option parser. You can also make an instance of a parser with `require("nomnom")()`. You can chain any of these functions off of a parser:


#### option

Add an option specification with the given name:

```javascript
nomnom.option('debug', {
   abbr: 'd',
   flag: true,
   help: "Print debugging info"
})
```


#### options

Add options as a hash keyed by option name, good for a cli with tons of options like [this example](http://github.com/harthur/replace/blob/master/bin/replace.js):

```javascript
nomnom.options({
   debug: {
      abbr: 'd',
      flag: true,
      help: "Print debugging info"
   },
   fruit: {
      help: "Fruit to buy"
   }
})
```


#### usage

The string that will override the default generated usage message.


#### help

A string that is appended to the usage.


#### autoShowUsage

The `enable` argument determines if nomnom will automatically print the usage when no commandline argument has been specified at all; the default is `true` i.e. the feature is enabled. Pass `false` to *disable* this feature.


#### getUsage

Return the generated usage message. When `.command(...)` has been called before, the usage message for that last 'active' command will be produced. 


#### script

Nomnom can't detect the alias used to run your script. You can use `script` to provide the correct name for the usage printout instead of e.g. `node test.js`.


#### printer

Overrides the usage printing function.


#### command

Takes a command name and gives you a command object on which you can chain command options.

When you provide a callback function via the `.callback()` API, then that callback will be invoked when the commandline has been parsed and the given command has been found there.
See [`.callback()`](#callback) for details.

When you did not provide a name argument or a null/undefined name, this API is equivalent to invoking `.nocommand()`.


#### nocommand

Gives a command object that will be used when no command is called.

When you provide a callback function via the `.callback()` API, then that callback will be invoked when the commandline has been parsed and 
*either* no command has been found there 
*or* a command was found for whicch no callback has been specified.
See [`.callback()`](#callback) for details.


#### nocolors

Disables coloring of the usage message.


#### setColors

Override the help/report formatting object with your own to provide custom coloring schemes. It should provide these functions:

```javascript
{
  usageHeadingColor: f1,
  usageStringColor: f2,
  positionalHelpColor: f3,
  optionsHeaderColor: f4,
  helpColor: f5,
  requiredArgColor: f6
};
```

where `f1` through `f6` are function references for functions which receive a single string and should return a (processed/transformed) string including the desired coloring console escape sequences. 


#### parse

Parses node's `process.argv` and returns the parsed options hash. You can also provide argv:

```javascript
var opts = nomnom.parse(["-xvf", "--atomic=true"])
```


#### nom

The same as `parse()`.


# Command interface

A command is specified with `nomnom.command('name')`. All these functions can be chained on a command:


#### option

Add an option specifically for this command.


#### options

Add options for this command as a hash of options keyed by name.


#### callback

A callback that will be called with the parsed options when the command is used. The arguments passed to the callback are a filled `options` object and the command name. 

When the `.command()` section of the setup code does *not* specify a callback, then the "fallback callback" will be invoked instead. This callback is the one defined in the `.nocommand()` a.k.a. empty `.command()` (without any `name` argument). Then the `command` name parameter passed to the provided callback will be `null`.



#### help

A help string describing the function of this command.


#### usage

Override the default generated usage string for this command.