bitburner-src/markdown/bitburner.ns.flags.md

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NS.flags() method

Parse command line flags.

Signature:

flags(schema: [string, string | number | boolean | string[]][]): { [key: string]: ScriptArg | string[] };

Parameters

Parameter	Type	Description
schema	[string, string | number | boolean | string[]][]

Returns:

{ [key: string]: ScriptArg | string[] }

Remarks

RAM cost: 0 GB

Allows Unix-like flag parsing.

We support 2 forms:

• Short form: the flag contains only 1 character, e.g. -v.

• Long form: the flag contains more than 1 character, e.g. --version.

Note that if an argument is given and its default value is nullish, the parsed value will be a string. This may cause subtle issues if you are not careful with type coercion.

Example

export async function main(ns) {
  const data = ns.flags([
    ['delay', 0], // a default number means this flag is a number
    ['server', 'foodnstuff'], //  a default string means this flag is a string
    ['exclude', []], // a default array means this flag is a default array of string
    ['help', false], // a default boolean means this flag is a boolean
    ['v', false], // short form
  ]);
  ns.tprint(data);
}

// [home /]> run example.js
// {"_":[],"delay":0,"server":"foodnstuff","exclude":[],"help":false,"v":false}
// [home /]> run example.js --delay 3000
// {"_":[],"delay":3000,"server":"foodnstuff","exclude":[],"help":false,"v":false}
// [home /]> run example.js --delay 3000 --server harakiri-sushi
// {"_":[],"delay":3000,"server":"harakiri-sushi","exclude":[],"help":false,"v":false}
// [home /]> run example.js --delay 3000 --server harakiri-sushi hello world
// {"_":["hello","world"],"delay":3000,"server":"harakiri-sushi","exclude":[],"help":false,"v":false}
// [home /]> run example.js --delay 3000 --server harakiri-sushi hello world --exclude a --exclude b
// {"_":["hello","world"],"delay":3000,"server":"harakiri-sushi","exclude":["a","b"],"help":false,"v":false}
// [home /]> run example.js --help
// {"_":[],"delay":0,"server":"foodnstuff","exclude":[],"help":true,"v":false}
// [home /]> run example.js -v
// {"_":[],"delay":0,"server":"foodnstuff","exclude":[],"help":false,"v":true}

export async function main(ns) {
  const data = ns.flags([
    ["foo", null],
    ["bar", undefined],
  ]);
  console.log(data);
}

// [home /]> run example.js
// { _: [], foo: null, bar: undefined }
// [home /]> run example.js --foo 1000
// { _: [], foo: "1000", bar: undefined }
// [home /]> run example.js --foo 1000 --bar false
// { _: [], foo: "1000", bar: "false" }

bar in the last example is "false" (a string), not false (a boolean). data.bar is truthy, not falsy.