These definitions were written by [Martin Poelstra](https://github.com/poelstra), [Mizunashi Mana](https://github.com/mizunashi-mana), [Jeffery Grajkowski](https://github.com/pushplay), [Jimi (Dimitris) Charalampidis](https://github.com/JimiC), [Steffen Viken Valvåg](https://github.com/steffenvv), [Emily Marigold Klassen](https://github.com/forivall), [ExE Boss](https://github.com/ExE-Boss), and [Aankhen](https://github.com/Aankhen).
* Provide a synchronous function to coerce or transform the value(s) given on the command line for `key`.
*
* The coercion function should accept one argument, representing the parsed value from the command line, and should return a new value or throw an error.
* The returned value will be used as the value for `key` (or one of its aliases) in `argv`.
*
* If the function throws, the error will be treated as a validation failure, delegating to either a custom `.fail()` handler or printing the error message in the console.
*
* Coercion will be applied to a value after all other modifications, such as `.normalize()`.
*
* Optionally `.coerce()` can take an object that maps several keys to their respective coercion function.
*
* You can also map the same function to several keys at one time. Just pass an array of keys as the first argument to `.coerce()`.
*
* If you are using dot-notion or arrays, .e.g., `user.email` and `user.password`, coercion will be applied to the final object that has been parsed
* Enable bash/zsh-completion shortcuts for commands and options.
*
* If invoked without parameters, `.completion()` will make completion the command to output the completion script.
*
* @param [cmd] When present in `argv._`, will result in the `.bashrc` or `.zshrc` completion script being outputted.
* To enable bash/zsh completions, concat the generated script to your `.bashrc` or `.bash_profile` (or `.zshrc` for zsh).
* @param [description] Provide a description in your usage instructions for the command that generates the completion scripts.
* @param [func] Rather than relying on yargs' default completion functionality, which shiver me timbers is pretty awesome, you can provide your own completion method.
* Interpret `key` as a boolean flag, but set its parsed value to the number of flag occurrences rather than `true` or `false`. Default value is thus `0`.
* You can demand a minimum and a maximum number a user can have within your program, as well as provide corresponding error messages if either of the demands is not met.
/** Should yargs attempt to detect the os' locale? Defaults to `true`. */
detectLocale(detect:boolean):Argv<T>;
/**
* Tell yargs to parse environment variables matching the given prefix and apply them to argv as though they were command line arguments.
*
* Use the "__" separator in the environment variable to indicate nested options. (e.g. prefix_nested__foo => nested.foo)
*
* If this method is called with no argument or with an empty string or with true, then all env vars will be applied to argv.
*
* Program arguments are defined in this order of precedence:
* 1. Command line args
* 2. Env vars
* 3. Config file/objects
* 4. Configured defaults
*
* Env var parsing is disabled by default, but you can also explicitly disable it by calling `.env(false)`, e.g. if you need to undo previous configuration.
*/
env():Argv<T>;
env(prefix:string):Argv<T>;
env(enable:boolean):Argv<T>;
/** A message to print at the end of the usage instructions */
epilog(msg:string):Argv<T>;
/** A message to print at the end of the usage instructions */
epilogue(msg:string):Argv<T>;
/**
* Give some example invocations of your program.
* Inside `cmd`, the string `$0` will get interpolated to the current script name or node command for the present script similar to how `$0` works in bash or perl.
* Examples will be printed out as part of the help message.
/** Manually indicate that the program should exit, and provide context about why we wanted to exit. Follows the behavior set by `.exitProcess().` */
exit(code:number,err:Error):void;
/**
* By default, yargs exits the process when the user passes a help flag, the user uses the `.version` functionality, validation fails, or the command handler fails.
* Calling `.exitProcess(false)` disables this behavior, enabling further actions after yargs have been validated.
*/
exitProcess(enabled:boolean):Argv<T>;
/**
* Method to execute when a failure occurs, rather than printing the failure message.
* @param func Is called with the failure message that would have been printed, the Error instance originally thrown and yargs state when the failure occurred.
* Given the key `x` is set, it is required that the key `y` is set.
* y` can either be the name of an argument to imply, a number indicating the position of an argument or an array of multiple implications to associate with `x`.
*
* Optionally `.implies()` can accept an object specifying multiple implications.
* Return the locale that yargs is currently using.
*
* By default, yargs will auto-detect the operating system's locale so that yargs-generated help content will display in the user's language.
*/
locale():string;
/**
* Override the auto-detected locale from the user's operating system with a static locale.
* Note that the OS locale can be modified by setting/exporting the `LC_ALL` environment variable.
*/
locale(loc:string):Argv<T>;
/**
* Define global middleware functions to be called first, in list order, for all cli command.
* @param callbacks Can be a function or a list of functions. Each callback gets passed a reference to argv.
* @param [applyBeforeValidation] Set to `true` to apply middleware before validation. This will execute the middleware prior to validation checks, but after parsing.
* Allows you to configure a command's positional arguments with an API similar to `.option()`.
* `.positional()` should be called in a command's builder function, and is not available on the top-level yargs instance. If so, it will throw an error.
* Override the default strings used by yargs with the key/value pairs provided in obj
*
* If you explicitly specify a locale(), you should do so before calling `updateStrings()`.
*/
updateStrings(obj:{[key:string]:string}):Argv<T>;
/**
* Set a usage message to show which commands to use.
* Inside `message`, the string `$0` will get interpolated to the current script name or node command for the present script similar to how `$0` works in bash or perl.
*
* If the optional `description`/`builder`/`handler` are provided, `.usage()` acts an an alias for `.command()`.
* This allows you to use `.usage()` to configure the default command that will be run as an entry-point to your application
* and allows you to provide configuration for the positional arguments accepted by your program:
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.
Default: `false`*(Matches any ANSI escape codes in a string)*
Match only the first ANSI escape.
## FAQ
### Why do you test for codes not in the ECMA 48 standard?
Some of the codes we run as a test are codes that we acquired finding various lists of non-standard or manufacturer specific codes. We test for both standard and non-standard codes, as most of them follow the same or similar format and can be safely matched in strings without the risk of removing actual string content. There are a few non-standard control codes that do not follow the traditional format (i.e. they end in numbers) thus forcing us to exclude them from the test because we cannot reliably match them.
On the historical side, those ECMA standards were established in the early 90's whereas the VT100, for example, was designed in the mid/late 70's. At that point in time, control codes were still pretty ungoverned and engineers used them for a multitude of things, namely to activate hardware ports that may have been proprietary. Somewhere else you see a similar 'anarchy' of codes is in the x86 architecture for processors; there are a ton of "interrupts" that can mean different things on certain brands of processors, most of which have been phased out.
## Maintainers
-[Sindre Sorhus](https://github.com/sindresorhus)
-[Josh Junon](https://github.com/qix-)
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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.
